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llvm-6502/lib/CodeGen/SelectionDAG/TargetLowering.cpp
Benjamin Kramer 1c10b8de46 BuildUDIV: If the divisor is even we can simplify the fixup of the multiplied value by introducing an early shift. 
This allows us to compile "unsigned foo(unsigned x) { return x/28; }" into
	shrl	$2, %edi
	imulq	$613566757, %rdi, %rax
	shrq	$32, %rax
	ret

instead of
	movl    %edi, %eax
	imulq   $613566757, %rax, %rcx
	shrq    $32, %rcx
	subl    %ecx, %eax
	shrl    %eax
	addl    %ecx, %eax
	shrl    $4, %eax

on x86_64

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127829 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-17 20:39:14 +00:00

3228 lines
127 KiB
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//===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements the TargetLowering class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetLowering.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/GlobalVariable.h"
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include <cctype>
using namespace llvm;
namespace llvm {
TLSModel::Model getTLSModel(const GlobalValue *GV, Reloc::Model reloc) {
bool isLocal = GV->hasLocalLinkage();
bool isDeclaration = GV->isDeclaration();
// FIXME: what should we do for protected and internal visibility?
// For variables, is internal different from hidden?
bool isHidden = GV->hasHiddenVisibility();
if (reloc == Reloc::PIC_) {
if (isLocal || isHidden)
return TLSModel::LocalDynamic;
else
return TLSModel::GeneralDynamic;
} else {
if (!isDeclaration || isHidden)
return TLSModel::LocalExec;
else
return TLSModel::InitialExec;
}
}
}
/// InitLibcallNames - Set default libcall names.
///
static void InitLibcallNames(const char **Names) {
Names[RTLIB::SHL_I16] = "__ashlhi3";
Names[RTLIB::SHL_I32] = "__ashlsi3";
Names[RTLIB::SHL_I64] = "__ashldi3";
Names[RTLIB::SHL_I128] = "__ashlti3";
Names[RTLIB::SRL_I16] = "__lshrhi3";
Names[RTLIB::SRL_I32] = "__lshrsi3";
Names[RTLIB::SRL_I64] = "__lshrdi3";
Names[RTLIB::SRL_I128] = "__lshrti3";
Names[RTLIB::SRA_I16] = "__ashrhi3";
Names[RTLIB::SRA_I32] = "__ashrsi3";
Names[RTLIB::SRA_I64] = "__ashrdi3";
Names[RTLIB::SRA_I128] = "__ashrti3";
Names[RTLIB::MUL_I8] = "__mulqi3";
Names[RTLIB::MUL_I16] = "__mulhi3";
Names[RTLIB::MUL_I32] = "__mulsi3";
Names[RTLIB::MUL_I64] = "__muldi3";
Names[RTLIB::MUL_I128] = "__multi3";
Names[RTLIB::SDIV_I8] = "__divqi3";
Names[RTLIB::SDIV_I16] = "__divhi3";
Names[RTLIB::SDIV_I32] = "__divsi3";
Names[RTLIB::SDIV_I64] = "__divdi3";
Names[RTLIB::SDIV_I128] = "__divti3";
Names[RTLIB::UDIV_I8] = "__udivqi3";
Names[RTLIB::UDIV_I16] = "__udivhi3";
Names[RTLIB::UDIV_I32] = "__udivsi3";
Names[RTLIB::UDIV_I64] = "__udivdi3";
Names[RTLIB::UDIV_I128] = "__udivti3";
Names[RTLIB::SREM_I8] = "__modqi3";
Names[RTLIB::SREM_I16] = "__modhi3";
Names[RTLIB::SREM_I32] = "__modsi3";
Names[RTLIB::SREM_I64] = "__moddi3";
Names[RTLIB::SREM_I128] = "__modti3";
Names[RTLIB::UREM_I8] = "__umodqi3";
Names[RTLIB::UREM_I16] = "__umodhi3";
Names[RTLIB::UREM_I32] = "__umodsi3";
Names[RTLIB::UREM_I64] = "__umoddi3";
Names[RTLIB::UREM_I128] = "__umodti3";
Names[RTLIB::NEG_I32] = "__negsi2";
Names[RTLIB::NEG_I64] = "__negdi2";
Names[RTLIB::ADD_F32] = "__addsf3";
Names[RTLIB::ADD_F64] = "__adddf3";
Names[RTLIB::ADD_F80] = "__addxf3";
Names[RTLIB::ADD_PPCF128] = "__gcc_qadd";
Names[RTLIB::SUB_F32] = "__subsf3";
Names[RTLIB::SUB_F64] = "__subdf3";
Names[RTLIB::SUB_F80] = "__subxf3";
Names[RTLIB::SUB_PPCF128] = "__gcc_qsub";
Names[RTLIB::MUL_F32] = "__mulsf3";
Names[RTLIB::MUL_F64] = "__muldf3";
Names[RTLIB::MUL_F80] = "__mulxf3";
Names[RTLIB::MUL_PPCF128] = "__gcc_qmul";
Names[RTLIB::DIV_F32] = "__divsf3";
Names[RTLIB::DIV_F64] = "__divdf3";
Names[RTLIB::DIV_F80] = "__divxf3";
Names[RTLIB::DIV_PPCF128] = "__gcc_qdiv";
Names[RTLIB::REM_F32] = "fmodf";
Names[RTLIB::REM_F64] = "fmod";
Names[RTLIB::REM_F80] = "fmodl";
Names[RTLIB::REM_PPCF128] = "fmodl";
Names[RTLIB::POWI_F32] = "__powisf2";
Names[RTLIB::POWI_F64] = "__powidf2";
Names[RTLIB::POWI_F80] = "__powixf2";
Names[RTLIB::POWI_PPCF128] = "__powitf2";
Names[RTLIB::SQRT_F32] = "sqrtf";
Names[RTLIB::SQRT_F64] = "sqrt";
Names[RTLIB::SQRT_F80] = "sqrtl";
Names[RTLIB::SQRT_PPCF128] = "sqrtl";
Names[RTLIB::LOG_F32] = "logf";
Names[RTLIB::LOG_F64] = "log";
Names[RTLIB::LOG_F80] = "logl";
Names[RTLIB::LOG_PPCF128] = "logl";
Names[RTLIB::LOG2_F32] = "log2f";
Names[RTLIB::LOG2_F64] = "log2";
Names[RTLIB::LOG2_F80] = "log2l";
Names[RTLIB::LOG2_PPCF128] = "log2l";
Names[RTLIB::LOG10_F32] = "log10f";
Names[RTLIB::LOG10_F64] = "log10";
Names[RTLIB::LOG10_F80] = "log10l";
Names[RTLIB::LOG10_PPCF128] = "log10l";
Names[RTLIB::EXP_F32] = "expf";
Names[RTLIB::EXP_F64] = "exp";
Names[RTLIB::EXP_F80] = "expl";
Names[RTLIB::EXP_PPCF128] = "expl";
Names[RTLIB::EXP2_F32] = "exp2f";
Names[RTLIB::EXP2_F64] = "exp2";
Names[RTLIB::EXP2_F80] = "exp2l";
Names[RTLIB::EXP2_PPCF128] = "exp2l";
Names[RTLIB::SIN_F32] = "sinf";
Names[RTLIB::SIN_F64] = "sin";
Names[RTLIB::SIN_F80] = "sinl";
Names[RTLIB::SIN_PPCF128] = "sinl";
Names[RTLIB::COS_F32] = "cosf";
Names[RTLIB::COS_F64] = "cos";
Names[RTLIB::COS_F80] = "cosl";
Names[RTLIB::COS_PPCF128] = "cosl";
Names[RTLIB::POW_F32] = "powf";
Names[RTLIB::POW_F64] = "pow";
Names[RTLIB::POW_F80] = "powl";
Names[RTLIB::POW_PPCF128] = "powl";
Names[RTLIB::CEIL_F32] = "ceilf";
Names[RTLIB::CEIL_F64] = "ceil";
Names[RTLIB::CEIL_F80] = "ceill";
Names[RTLIB::CEIL_PPCF128] = "ceill";
Names[RTLIB::TRUNC_F32] = "truncf";
Names[RTLIB::TRUNC_F64] = "trunc";
Names[RTLIB::TRUNC_F80] = "truncl";
Names[RTLIB::TRUNC_PPCF128] = "truncl";
Names[RTLIB::RINT_F32] = "rintf";
Names[RTLIB::RINT_F64] = "rint";
Names[RTLIB::RINT_F80] = "rintl";
Names[RTLIB::RINT_PPCF128] = "rintl";
Names[RTLIB::NEARBYINT_F32] = "nearbyintf";
Names[RTLIB::NEARBYINT_F64] = "nearbyint";
Names[RTLIB::NEARBYINT_F80] = "nearbyintl";
Names[RTLIB::NEARBYINT_PPCF128] = "nearbyintl";
Names[RTLIB::FLOOR_F32] = "floorf";
Names[RTLIB::FLOOR_F64] = "floor";
Names[RTLIB::FLOOR_F80] = "floorl";
Names[RTLIB::FLOOR_PPCF128] = "floorl";
Names[RTLIB::COPYSIGN_F32] = "copysignf";
Names[RTLIB::COPYSIGN_F64] = "copysign";
Names[RTLIB::COPYSIGN_F80] = "copysignl";
Names[RTLIB::COPYSIGN_PPCF128] = "copysignl";
Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2";
Names[RTLIB::FPEXT_F16_F32] = "__gnu_h2f_ieee";
Names[RTLIB::FPROUND_F32_F16] = "__gnu_f2h_ieee";
Names[RTLIB::FPROUND_F64_F32] = "__truncdfsf2";
Names[RTLIB::FPROUND_F80_F32] = "__truncxfsf2";
Names[RTLIB::FPROUND_PPCF128_F32] = "__trunctfsf2";
Names[RTLIB::FPROUND_F80_F64] = "__truncxfdf2";
Names[RTLIB::FPROUND_PPCF128_F64] = "__trunctfdf2";
Names[RTLIB::FPTOSINT_F32_I8] = "__fixsfqi";
Names[RTLIB::FPTOSINT_F32_I16] = "__fixsfhi";
Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi";
Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi";
Names[RTLIB::FPTOSINT_F32_I128] = "__fixsfti";
Names[RTLIB::FPTOSINT_F64_I8] = "__fixdfqi";
Names[RTLIB::FPTOSINT_F64_I16] = "__fixdfhi";
Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi";
Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi";
Names[RTLIB::FPTOSINT_F64_I128] = "__fixdfti";
Names[RTLIB::FPTOSINT_F80_I32] = "__fixxfsi";
Names[RTLIB::FPTOSINT_F80_I64] = "__fixxfdi";
Names[RTLIB::FPTOSINT_F80_I128] = "__fixxfti";
Names[RTLIB::FPTOSINT_PPCF128_I32] = "__fixtfsi";
Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi";
Names[RTLIB::FPTOSINT_PPCF128_I128] = "__fixtfti";
Names[RTLIB::FPTOUINT_F32_I8] = "__fixunssfqi";
Names[RTLIB::FPTOUINT_F32_I16] = "__fixunssfhi";
Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi";
Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi";
Names[RTLIB::FPTOUINT_F32_I128] = "__fixunssfti";
Names[RTLIB::FPTOUINT_F64_I8] = "__fixunsdfqi";
Names[RTLIB::FPTOUINT_F64_I16] = "__fixunsdfhi";
Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi";
Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi";
Names[RTLIB::FPTOUINT_F64_I128] = "__fixunsdfti";
Names[RTLIB::FPTOUINT_F80_I32] = "__fixunsxfsi";
Names[RTLIB::FPTOUINT_F80_I64] = "__fixunsxfdi";
Names[RTLIB::FPTOUINT_F80_I128] = "__fixunsxfti";
Names[RTLIB::FPTOUINT_PPCF128_I32] = "__fixunstfsi";
Names[RTLIB::FPTOUINT_PPCF128_I64] = "__fixunstfdi";
Names[RTLIB::FPTOUINT_PPCF128_I128] = "__fixunstfti";
Names[RTLIB::SINTTOFP_I32_F32] = "__floatsisf";
Names[RTLIB::SINTTOFP_I32_F64] = "__floatsidf";
Names[RTLIB::SINTTOFP_I32_F80] = "__floatsixf";
Names[RTLIB::SINTTOFP_I32_PPCF128] = "__floatsitf";
Names[RTLIB::SINTTOFP_I64_F32] = "__floatdisf";
Names[RTLIB::SINTTOFP_I64_F64] = "__floatdidf";
Names[RTLIB::SINTTOFP_I64_F80] = "__floatdixf";
Names[RTLIB::SINTTOFP_I64_PPCF128] = "__floatditf";
Names[RTLIB::SINTTOFP_I128_F32] = "__floattisf";
Names[RTLIB::SINTTOFP_I128_F64] = "__floattidf";
Names[RTLIB::SINTTOFP_I128_F80] = "__floattixf";
Names[RTLIB::SINTTOFP_I128_PPCF128] = "__floattitf";
Names[RTLIB::UINTTOFP_I32_F32] = "__floatunsisf";
Names[RTLIB::UINTTOFP_I32_F64] = "__floatunsidf";
Names[RTLIB::UINTTOFP_I32_F80] = "__floatunsixf";
Names[RTLIB::UINTTOFP_I32_PPCF128] = "__floatunsitf";
Names[RTLIB::UINTTOFP_I64_F32] = "__floatundisf";
Names[RTLIB::UINTTOFP_I64_F64] = "__floatundidf";
Names[RTLIB::UINTTOFP_I64_F80] = "__floatundixf";
Names[RTLIB::UINTTOFP_I64_PPCF128] = "__floatunditf";
Names[RTLIB::UINTTOFP_I128_F32] = "__floatuntisf";
Names[RTLIB::UINTTOFP_I128_F64] = "__floatuntidf";
Names[RTLIB::UINTTOFP_I128_F80] = "__floatuntixf";
Names[RTLIB::UINTTOFP_I128_PPCF128] = "__floatuntitf";
Names[RTLIB::OEQ_F32] = "__eqsf2";
Names[RTLIB::OEQ_F64] = "__eqdf2";
Names[RTLIB::UNE_F32] = "__nesf2";
Names[RTLIB::UNE_F64] = "__nedf2";
Names[RTLIB::OGE_F32] = "__gesf2";
Names[RTLIB::OGE_F64] = "__gedf2";
Names[RTLIB::OLT_F32] = "__ltsf2";
Names[RTLIB::OLT_F64] = "__ltdf2";
Names[RTLIB::OLE_F32] = "__lesf2";
Names[RTLIB::OLE_F64] = "__ledf2";
Names[RTLIB::OGT_F32] = "__gtsf2";
Names[RTLIB::OGT_F64] = "__gtdf2";
Names[RTLIB::UO_F32] = "__unordsf2";
Names[RTLIB::UO_F64] = "__unorddf2";
Names[RTLIB::O_F32] = "__unordsf2";
Names[RTLIB::O_F64] = "__unorddf2";
Names[RTLIB::MEMCPY] = "memcpy";
Names[RTLIB::MEMMOVE] = "memmove";
Names[RTLIB::MEMSET] = "memset";
Names[RTLIB::UNWIND_RESUME] = "_Unwind_Resume";
Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_1] = "__sync_val_compare_and_swap_1";
Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_2] = "__sync_val_compare_and_swap_2";
Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_4] = "__sync_val_compare_and_swap_4";
Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_8] = "__sync_val_compare_and_swap_8";
Names[RTLIB::SYNC_LOCK_TEST_AND_SET_1] = "__sync_lock_test_and_set_1";
Names[RTLIB::SYNC_LOCK_TEST_AND_SET_2] = "__sync_lock_test_and_set_2";
Names[RTLIB::SYNC_LOCK_TEST_AND_SET_4] = "__sync_lock_test_and_set_4";
Names[RTLIB::SYNC_LOCK_TEST_AND_SET_8] = "__sync_lock_test_and_set_8";
Names[RTLIB::SYNC_FETCH_AND_ADD_1] = "__sync_fetch_and_add_1";
Names[RTLIB::SYNC_FETCH_AND_ADD_2] = "__sync_fetch_and_add_2";
Names[RTLIB::SYNC_FETCH_AND_ADD_4] = "__sync_fetch_and_add_4";
Names[RTLIB::SYNC_FETCH_AND_ADD_8] = "__sync_fetch_and_add_8";
Names[RTLIB::SYNC_FETCH_AND_SUB_1] = "__sync_fetch_and_sub_1";
Names[RTLIB::SYNC_FETCH_AND_SUB_2] = "__sync_fetch_and_sub_2";
Names[RTLIB::SYNC_FETCH_AND_SUB_4] = "__sync_fetch_and_sub_4";
Names[RTLIB::SYNC_FETCH_AND_SUB_8] = "__sync_fetch_and_sub_8";
Names[RTLIB::SYNC_FETCH_AND_AND_1] = "__sync_fetch_and_and_1";
Names[RTLIB::SYNC_FETCH_AND_AND_2] = "__sync_fetch_and_and_2";
Names[RTLIB::SYNC_FETCH_AND_AND_4] = "__sync_fetch_and_and_4";
Names[RTLIB::SYNC_FETCH_AND_AND_8] = "__sync_fetch_and_and_8";
Names[RTLIB::SYNC_FETCH_AND_OR_1] = "__sync_fetch_and_or_1";
Names[RTLIB::SYNC_FETCH_AND_OR_2] = "__sync_fetch_and_or_2";
Names[RTLIB::SYNC_FETCH_AND_OR_4] = "__sync_fetch_and_or_4";
Names[RTLIB::SYNC_FETCH_AND_OR_8] = "__sync_fetch_and_or_8";
Names[RTLIB::SYNC_FETCH_AND_XOR_1] = "__sync_fetch_and_xor_1";
Names[RTLIB::SYNC_FETCH_AND_XOR_2] = "__sync_fetch_and_xor_2";
Names[RTLIB::SYNC_FETCH_AND_XOR_4] = "__sync_fetch_and-xor_4";
Names[RTLIB::SYNC_FETCH_AND_XOR_8] = "__sync_fetch_and_xor_8";
Names[RTLIB::SYNC_FETCH_AND_NAND_1] = "__sync_fetch_and_nand_1";
Names[RTLIB::SYNC_FETCH_AND_NAND_2] = "__sync_fetch_and_nand_2";
Names[RTLIB::SYNC_FETCH_AND_NAND_4] = "__sync_fetch_and_nand_4";
Names[RTLIB::SYNC_FETCH_AND_NAND_8] = "__sync_fetch_and_nand_8";
}
/// InitLibcallCallingConvs - Set default libcall CallingConvs.
///
static void InitLibcallCallingConvs(CallingConv::ID *CCs) {
for (int i = 0; i < RTLIB::UNKNOWN_LIBCALL; ++i) {
CCs[i] = CallingConv::C;
}
}
/// getFPEXT - Return the FPEXT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
if (OpVT == MVT::f32) {
if (RetVT == MVT::f64)
return FPEXT_F32_F64;
}
return UNKNOWN_LIBCALL;
}
/// getFPROUND - Return the FPROUND_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
if (RetVT == MVT::f32) {
if (OpVT == MVT::f64)
return FPROUND_F64_F32;
if (OpVT == MVT::f80)
return FPROUND_F80_F32;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F32;
} else if (RetVT == MVT::f64) {
if (OpVT == MVT::f80)
return FPROUND_F80_F64;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F64;
}
return UNKNOWN_LIBCALL;
}
/// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
if (OpVT == MVT::f32) {
if (RetVT == MVT::i8)
return FPTOSINT_F32_I8;
if (RetVT == MVT::i16)
return FPTOSINT_F32_I16;
if (RetVT == MVT::i32)
return FPTOSINT_F32_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F32_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F32_I128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::i8)
return FPTOSINT_F64_I8;
if (RetVT == MVT::i16)
return FPTOSINT_F64_I16;
if (RetVT == MVT::i32)
return FPTOSINT_F64_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F64_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F64_I128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::i32)
return FPTOSINT_F80_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F80_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F80_I128;
} else if (OpVT == MVT::ppcf128) {
if (RetVT == MVT::i32)
return FPTOSINT_PPCF128_I32;
if (RetVT == MVT::i64)
return FPTOSINT_PPCF128_I64;
if (RetVT == MVT::i128)
return FPTOSINT_PPCF128_I128;
}
return UNKNOWN_LIBCALL;
}
/// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
if (OpVT == MVT::f32) {
if (RetVT == MVT::i8)
return FPTOUINT_F32_I8;
if (RetVT == MVT::i16)
return FPTOUINT_F32_I16;
if (RetVT == MVT::i32)
return FPTOUINT_F32_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F32_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F32_I128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::i8)
return FPTOUINT_F64_I8;
if (RetVT == MVT::i16)
return FPTOUINT_F64_I16;
if (RetVT == MVT::i32)
return FPTOUINT_F64_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F64_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F64_I128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::i32)
return FPTOUINT_F80_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F80_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F80_I128;
} else if (OpVT == MVT::ppcf128) {
if (RetVT == MVT::i32)
return FPTOUINT_PPCF128_I32;
if (RetVT == MVT::i64)
return FPTOUINT_PPCF128_I64;
if (RetVT == MVT::i128)
return FPTOUINT_PPCF128_I128;
}
return UNKNOWN_LIBCALL;
}
/// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
if (OpVT == MVT::i32) {
if (RetVT == MVT::f32)
return SINTTOFP_I32_F32;
else if (RetVT == MVT::f64)
return SINTTOFP_I32_F64;
else if (RetVT == MVT::f80)
return SINTTOFP_I32_F80;
else if (RetVT == MVT::ppcf128)
return SINTTOFP_I32_PPCF128;
} else if (OpVT == MVT::i64) {
if (RetVT == MVT::f32)
return SINTTOFP_I64_F32;
else if (RetVT == MVT::f64)
return SINTTOFP_I64_F64;
else if (RetVT == MVT::f80)
return SINTTOFP_I64_F80;
else if (RetVT == MVT::ppcf128)
return SINTTOFP_I64_PPCF128;
} else if (OpVT == MVT::i128) {
if (RetVT == MVT::f32)
return SINTTOFP_I128_F32;
else if (RetVT == MVT::f64)
return SINTTOFP_I128_F64;
else if (RetVT == MVT::f80)
return SINTTOFP_I128_F80;
else if (RetVT == MVT::ppcf128)
return SINTTOFP_I128_PPCF128;
}
return UNKNOWN_LIBCALL;
}
/// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
if (OpVT == MVT::i32) {
if (RetVT == MVT::f32)
return UINTTOFP_I32_F32;
else if (RetVT == MVT::f64)
return UINTTOFP_I32_F64;
else if (RetVT == MVT::f80)
return UINTTOFP_I32_F80;
else if (RetVT == MVT::ppcf128)
return UINTTOFP_I32_PPCF128;
} else if (OpVT == MVT::i64) {
if (RetVT == MVT::f32)
return UINTTOFP_I64_F32;
else if (RetVT == MVT::f64)
return UINTTOFP_I64_F64;
else if (RetVT == MVT::f80)
return UINTTOFP_I64_F80;
else if (RetVT == MVT::ppcf128)
return UINTTOFP_I64_PPCF128;
} else if (OpVT == MVT::i128) {
if (RetVT == MVT::f32)
return UINTTOFP_I128_F32;
else if (RetVT == MVT::f64)
return UINTTOFP_I128_F64;
else if (RetVT == MVT::f80)
return UINTTOFP_I128_F80;
else if (RetVT == MVT::ppcf128)
return UINTTOFP_I128_PPCF128;
}
return UNKNOWN_LIBCALL;
}
/// InitCmpLibcallCCs - Set default comparison libcall CC.
///
static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
CCs[RTLIB::UNE_F32] = ISD::SETNE;
CCs[RTLIB::UNE_F64] = ISD::SETNE;
CCs[RTLIB::OGE_F32] = ISD::SETGE;
CCs[RTLIB::OGE_F64] = ISD::SETGE;
CCs[RTLIB::OLT_F32] = ISD::SETLT;
CCs[RTLIB::OLT_F64] = ISD::SETLT;
CCs[RTLIB::OLE_F32] = ISD::SETLE;
CCs[RTLIB::OLE_F64] = ISD::SETLE;
CCs[RTLIB::OGT_F32] = ISD::SETGT;
CCs[RTLIB::OGT_F64] = ISD::SETGT;
CCs[RTLIB::UO_F32] = ISD::SETNE;
CCs[RTLIB::UO_F64] = ISD::SETNE;
CCs[RTLIB::O_F32] = ISD::SETEQ;
CCs[RTLIB::O_F64] = ISD::SETEQ;
}
/// NOTE: The constructor takes ownership of TLOF.
TargetLowering::TargetLowering(const TargetMachine &tm,
const TargetLoweringObjectFile *tlof)
: TM(tm), TD(TM.getTargetData()), TLOF(*tlof) {
// All operations default to being supported.
memset(OpActions, 0, sizeof(OpActions));
memset(LoadExtActions, 0, sizeof(LoadExtActions));
memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
memset(CondCodeActions, 0, sizeof(CondCodeActions));
// Set default actions for various operations.
for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) {
// Default all indexed load / store to expand.
for (unsigned IM = (unsigned)ISD::PRE_INC;
IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
setIndexedLoadAction(IM, (MVT::SimpleValueType)VT, Expand);
setIndexedStoreAction(IM, (MVT::SimpleValueType)VT, Expand);
}
// These operations default to expand.
setOperationAction(ISD::FGETSIGN, (MVT::SimpleValueType)VT, Expand);
setOperationAction(ISD::CONCAT_VECTORS, (MVT::SimpleValueType)VT, Expand);
}
// Most targets ignore the @llvm.prefetch intrinsic.
setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
// ConstantFP nodes default to expand. Targets can either change this to
// Legal, in which case all fp constants are legal, or use isFPImmLegal()
// to optimize expansions for certain constants.
setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
// These library functions default to expand.
setOperationAction(ISD::FLOG , MVT::f64, Expand);
setOperationAction(ISD::FLOG2, MVT::f64, Expand);
setOperationAction(ISD::FLOG10,MVT::f64, Expand);
setOperationAction(ISD::FEXP , MVT::f64, Expand);
setOperationAction(ISD::FEXP2, MVT::f64, Expand);
setOperationAction(ISD::FLOG , MVT::f32, Expand);
setOperationAction(ISD::FLOG2, MVT::f32, Expand);
setOperationAction(ISD::FLOG10,MVT::f32, Expand);
setOperationAction(ISD::FEXP , MVT::f32, Expand);
setOperationAction(ISD::FEXP2, MVT::f32, Expand);
// Default ISD::TRAP to expand (which turns it into abort).
setOperationAction(ISD::TRAP, MVT::Other, Expand);
IsLittleEndian = TD->isLittleEndian();
PointerTy = MVT::getIntegerVT(8*TD->getPointerSize());
memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
memset(TargetDAGCombineArray, 0, array_lengthof(TargetDAGCombineArray));
maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8;
maxStoresPerMemsetOptSize = maxStoresPerMemcpyOptSize
= maxStoresPerMemmoveOptSize = 4;
benefitFromCodePlacementOpt = false;
UseUnderscoreSetJmp = false;
UseUnderscoreLongJmp = false;
SelectIsExpensive = false;
IntDivIsCheap = false;
Pow2DivIsCheap = false;
JumpIsExpensive = false;
StackPointerRegisterToSaveRestore = 0;
ExceptionPointerRegister = 0;
ExceptionSelectorRegister = 0;
BooleanContents = UndefinedBooleanContent;
SchedPreferenceInfo = Sched::Latency;
JumpBufSize = 0;
JumpBufAlignment = 0;
PrefLoopAlignment = 0;
MinStackArgumentAlignment = 1;
ShouldFoldAtomicFences = false;
InitLibcallNames(LibcallRoutineNames);
InitCmpLibcallCCs(CmpLibcallCCs);
InitLibcallCallingConvs(LibcallCallingConvs);
}
TargetLowering::~TargetLowering() {
delete &TLOF;
}
MVT TargetLowering::getShiftAmountTy(EVT LHSTy) const {
return MVT::getIntegerVT(8*TD->getPointerSize());
}
/// canOpTrap - Returns true if the operation can trap for the value type.
/// VT must be a legal type.
bool TargetLowering::canOpTrap(unsigned Op, EVT VT) const {
assert(isTypeLegal(VT));
switch (Op) {
default:
return false;
case ISD::FDIV:
case ISD::FREM:
case ISD::SDIV:
case ISD::UDIV:
case ISD::SREM:
case ISD::UREM:
return true;
}
}
static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
unsigned &NumIntermediates,
EVT &RegisterVT,
TargetLowering *TLI) {
// Figure out the right, legal destination reg to copy into.
unsigned NumElts = VT.getVectorNumElements();
MVT EltTy = VT.getVectorElementType();
unsigned NumVectorRegs = 1;
// FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we
// could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(NumElts)) {
NumVectorRegs = NumElts;
NumElts = 1;
}
// Divide the input until we get to a supported size. This will always
// end with a scalar if the target doesn't support vectors.
while (NumElts > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, NumElts))) {
NumElts >>= 1;
NumVectorRegs <<= 1;
}
NumIntermediates = NumVectorRegs;
MVT NewVT = MVT::getVectorVT(EltTy, NumElts);
if (!TLI->isTypeLegal(NewVT))
NewVT = EltTy;
IntermediateVT = NewVT;
EVT DestVT = TLI->getRegisterType(NewVT);
RegisterVT = DestVT;
if (EVT(DestVT).bitsLT(NewVT)) // Value is expanded, e.g. i64 -> i16.
return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits());
// Otherwise, promotion or legal types use the same number of registers as
// the vector decimated to the appropriate level.
return NumVectorRegs;
}
/// isLegalRC - Return true if the value types that can be represented by the
/// specified register class are all legal.
bool TargetLowering::isLegalRC(const TargetRegisterClass *RC) const {
for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end();
I != E; ++I) {
if (isTypeLegal(*I))
return true;
}
return false;
}
/// hasLegalSuperRegRegClasses - Return true if the specified register class
/// has one or more super-reg register classes that are legal.
bool
TargetLowering::hasLegalSuperRegRegClasses(const TargetRegisterClass *RC) const{
if (*RC->superregclasses_begin() == 0)
return false;
for (TargetRegisterInfo::regclass_iterator I = RC->superregclasses_begin(),
E = RC->superregclasses_end(); I != E; ++I) {
const TargetRegisterClass *RRC = *I;
if (isLegalRC(RRC))
return true;
}
return false;
}
/// findRepresentativeClass - Return the largest legal super-reg register class
/// of the register class for the specified type and its associated "cost".
std::pair<const TargetRegisterClass*, uint8_t>
TargetLowering::findRepresentativeClass(EVT VT) const {
const TargetRegisterClass *RC = RegClassForVT[VT.getSimpleVT().SimpleTy];
if (!RC)
return std::make_pair(RC, 0);
const TargetRegisterClass *BestRC = RC;
for (TargetRegisterInfo::regclass_iterator I = RC->superregclasses_begin(),
E = RC->superregclasses_end(); I != E; ++I) {
const TargetRegisterClass *RRC = *I;
if (RRC->isASubClass() || !isLegalRC(RRC))
continue;
if (!hasLegalSuperRegRegClasses(RRC))
return std::make_pair(RRC, 1);
BestRC = RRC;
}
return std::make_pair(BestRC, 1);
}
/// computeRegisterProperties - Once all of the register classes are added,
/// this allows us to compute derived properties we expose.
void TargetLowering::computeRegisterProperties() {
assert(MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_VALUETYPE &&
"Too many value types for ValueTypeActions to hold!");
// Everything defaults to needing one register.
for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
NumRegistersForVT[i] = 1;
RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
}
// ...except isVoid, which doesn't need any registers.
NumRegistersForVT[MVT::isVoid] = 0;
// Find the largest integer register class.
unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg)
assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
// Every integer value type larger than this largest register takes twice as
// many registers to represent as the previous ValueType.
for (unsigned ExpandedReg = LargestIntReg + 1; ; ++ExpandedReg) {
EVT ExpandedVT = (MVT::SimpleValueType)ExpandedReg;
if (!ExpandedVT.isInteger())
break;
NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
ValueTypeActions.setTypeAction(ExpandedVT, Expand);
}
// Inspect all of the ValueType's smaller than the largest integer
// register to see which ones need promotion.
unsigned LegalIntReg = LargestIntReg;
for (unsigned IntReg = LargestIntReg - 1;
IntReg >= (unsigned)MVT::i1; --IntReg) {
EVT IVT = (MVT::SimpleValueType)IntReg;
if (isTypeLegal(IVT)) {
LegalIntReg = IntReg;
} else {
RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
(MVT::SimpleValueType)LegalIntReg;
ValueTypeActions.setTypeAction(IVT, Promote);
}
}
// ppcf128 type is really two f64's.
if (!isTypeLegal(MVT::ppcf128)) {
NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
TransformToType[MVT::ppcf128] = MVT::f64;
ValueTypeActions.setTypeAction(MVT::ppcf128, Expand);
}
// Decide how to handle f64. If the target does not have native f64 support,
// expand it to i64 and we will be generating soft float library calls.
if (!isTypeLegal(MVT::f64)) {
NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
TransformToType[MVT::f64] = MVT::i64;
ValueTypeActions.setTypeAction(MVT::f64, Expand);
}
// Decide how to handle f32. If the target does not have native support for
// f32, promote it to f64 if it is legal. Otherwise, expand it to i32.
if (!isTypeLegal(MVT::f32)) {
if (isTypeLegal(MVT::f64)) {
NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::f64];
RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::f64];
TransformToType[MVT::f32] = MVT::f64;
ValueTypeActions.setTypeAction(MVT::f32, Promote);
} else {
NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
TransformToType[MVT::f32] = MVT::i32;
ValueTypeActions.setTypeAction(MVT::f32, Expand);
}
}
// Loop over all of the vector value types to see which need transformations.
for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
MVT VT = (MVT::SimpleValueType)i;
if (isTypeLegal(VT)) continue;
// Determine if there is a legal wider type. If so, we should promote to
// that wider vector type.
EVT EltVT = VT.getVectorElementType();
unsigned NElts = VT.getVectorNumElements();
if (NElts != 1) {
bool IsLegalWiderType = false;
for (unsigned nVT = i+1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
EVT SVT = (MVT::SimpleValueType)nVT;
if (SVT.getVectorElementType() == EltVT &&
SVT.getVectorNumElements() > NElts &&
isTypeLegal(SVT)) {
TransformToType[i] = SVT;
RegisterTypeForVT[i] = SVT;
NumRegistersForVT[i] = 1;
ValueTypeActions.setTypeAction(VT, Promote);
IsLegalWiderType = true;
break;
}
}
if (IsLegalWiderType) continue;
}
MVT IntermediateVT;
EVT RegisterVT;
unsigned NumIntermediates;
NumRegistersForVT[i] =
getVectorTypeBreakdownMVT(VT, IntermediateVT, NumIntermediates,
RegisterVT, this);
RegisterTypeForVT[i] = RegisterVT;
EVT NVT = VT.getPow2VectorType();
if (NVT == VT) {
// Type is already a power of 2. The default action is to split.
TransformToType[i] = MVT::Other;
ValueTypeActions.setTypeAction(VT, Expand);
} else {
TransformToType[i] = NVT;
ValueTypeActions.setTypeAction(VT, Promote);
}
}
// Determine the 'representative' register class for each value type.
// An representative register class is the largest (meaning one which is
// not a sub-register class / subreg register class) legal register class for
// a group of value types. For example, on i386, i8, i16, and i32
// representative would be GR32; while on x86_64 it's GR64.
for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
const TargetRegisterClass* RRC;
uint8_t Cost;
tie(RRC, Cost) = findRepresentativeClass((MVT::SimpleValueType)i);
RepRegClassForVT[i] = RRC;
RepRegClassCostForVT[i] = Cost;
}
}
const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
return NULL;
}
MVT::SimpleValueType TargetLowering::getSetCCResultType(EVT VT) const {
return PointerTy.SimpleTy;
}
MVT::SimpleValueType TargetLowering::getCmpLibcallReturnType() const {
return MVT::i32; // return the default value
}
/// getVectorTypeBreakdown - Vector types are broken down into some number of
/// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32
/// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
/// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
///
/// This method returns the number of registers needed, and the VT for each
/// register. It also returns the VT and quantity of the intermediate values
/// before they are promoted/expanded.
///
unsigned TargetLowering::getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
EVT &IntermediateVT,
unsigned &NumIntermediates,
EVT &RegisterVT) const {
unsigned NumElts = VT.getVectorNumElements();
// If there is a wider vector type with the same element type as this one,
// we should widen to that legal vector type. This handles things like
// <2 x float> -> <4 x float>.
if (NumElts != 1 && getTypeAction(VT) == Promote) {
RegisterVT = getTypeToTransformTo(Context, VT);
if (isTypeLegal(RegisterVT)) {
IntermediateVT = RegisterVT;
NumIntermediates = 1;
return 1;
}
}
// Figure out the right, legal destination reg to copy into.
EVT EltTy = VT.getVectorElementType();
unsigned NumVectorRegs = 1;
// FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we
// could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(NumElts)) {
NumVectorRegs = NumElts;
NumElts = 1;
}
// Divide the input until we get to a supported size. This will always
// end with a scalar if the target doesn't support vectors.
while (NumElts > 1 && !isTypeLegal(
EVT::getVectorVT(Context, EltTy, NumElts))) {
NumElts >>= 1;
NumVectorRegs <<= 1;
}
NumIntermediates = NumVectorRegs;
EVT NewVT = EVT::getVectorVT(Context, EltTy, NumElts);
if (!isTypeLegal(NewVT))
NewVT = EltTy;
IntermediateVT = NewVT;
EVT DestVT = getRegisterType(Context, NewVT);
RegisterVT = DestVT;
if (DestVT.bitsLT(NewVT)) // Value is expanded, e.g. i64 -> i16.
return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits());
// Otherwise, promotion or legal types use the same number of registers as
// the vector decimated to the appropriate level.
return NumVectorRegs;
}
/// Get the EVTs and ArgFlags collections that represent the legalized return
/// type of the given function. This does not require a DAG or a return value,
/// and is suitable for use before any DAGs for the function are constructed.
/// TODO: Move this out of TargetLowering.cpp.
void llvm::GetReturnInfo(const Type* ReturnType, Attributes attr,
SmallVectorImpl<ISD::OutputArg> &Outs,
const TargetLowering &TLI,
SmallVectorImpl<uint64_t> *Offsets) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, ReturnType, ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0) return;
unsigned Offset = 0;
for (unsigned j = 0, f = NumValues; j != f; ++j) {
EVT VT = ValueVTs[j];
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (attr & Attribute::SExt)
ExtendKind = ISD::SIGN_EXTEND;
else if (attr & Attribute::ZExt)
ExtendKind = ISD::ZERO_EXTEND;
// FIXME: C calling convention requires the return type to be promoted to
// at least 32-bit. But this is not necessary for non-C calling
// conventions. The frontend should mark functions whose return values
// require promoting with signext or zeroext attributes.
if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) {
EVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32);
if (VT.bitsLT(MinVT))
VT = MinVT;
}
unsigned NumParts = TLI.getNumRegisters(ReturnType->getContext(), VT);
EVT PartVT = TLI.getRegisterType(ReturnType->getContext(), VT);
unsigned PartSize = TLI.getTargetData()->getTypeAllocSize(
PartVT.getTypeForEVT(ReturnType->getContext()));
// 'inreg' on function refers to return value
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
if (attr & Attribute::InReg)
Flags.setInReg();
// Propagate extension type if any
if (attr & Attribute::SExt)
Flags.setSExt();
else if (attr & Attribute::ZExt)
Flags.setZExt();
for (unsigned i = 0; i < NumParts; ++i) {
Outs.push_back(ISD::OutputArg(Flags, PartVT, /*isFixed=*/true));
if (Offsets) {
Offsets->push_back(Offset);
Offset += PartSize;
}
}
}
}
/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
/// function arguments in the caller parameter area. This is the actual
/// alignment, not its logarithm.
unsigned TargetLowering::getByValTypeAlignment(const Type *Ty) const {
return TD->getCallFrameTypeAlignment(Ty);
}
/// getJumpTableEncoding - Return the entry encoding for a jump table in the
/// current function. The returned value is a member of the
/// MachineJumpTableInfo::JTEntryKind enum.
unsigned TargetLowering::getJumpTableEncoding() const {
// In non-pic modes, just use the address of a block.
if (getTargetMachine().getRelocationModel() != Reloc::PIC_)
return MachineJumpTableInfo::EK_BlockAddress;
// In PIC mode, if the target supports a GPRel32 directive, use it.
if (getTargetMachine().getMCAsmInfo()->getGPRel32Directive() != 0)
return MachineJumpTableInfo::EK_GPRel32BlockAddress;
// Otherwise, use a label difference.
return MachineJumpTableInfo::EK_LabelDifference32;
}
SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
SelectionDAG &DAG) const {
// If our PIC model is GP relative, use the global offset table as the base.
if (getJumpTableEncoding() == MachineJumpTableInfo::EK_GPRel32BlockAddress)
return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy());
return Table;
}
/// getPICJumpTableRelocBaseExpr - This returns the relocation base for the
/// given PIC jumptable, the same as getPICJumpTableRelocBase, but as an
/// MCExpr.
const MCExpr *
TargetLowering::getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
unsigned JTI,MCContext &Ctx) const{
// The normal PIC reloc base is the label at the start of the jump table.
return MCSymbolRefExpr::Create(MF->getJTISymbol(JTI, Ctx), Ctx);
}
bool
TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
// Assume that everything is safe in static mode.
if (getTargetMachine().getRelocationModel() == Reloc::Static)
return true;
// In dynamic-no-pic mode, assume that known defined values are safe.
if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC &&
GA &&
!GA->getGlobal()->isDeclaration() &&
!GA->getGlobal()->isWeakForLinker())
return true;
// Otherwise assume nothing is safe.
return false;
}
//===----------------------------------------------------------------------===//
// Optimization Methods
//===----------------------------------------------------------------------===//
/// ShrinkDemandedConstant - Check to see if the specified operand of the
/// specified instruction is a constant integer. If so, check to see if there
/// are any bits set in the constant that are not demanded. If so, shrink the
/// constant and return true.
bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDValue Op,
const APInt &Demanded) {
DebugLoc dl = Op.getDebugLoc();
// FIXME: ISD::SELECT, ISD::SELECT_CC
switch (Op.getOpcode()) {
default: break;
case ISD::XOR:
case ISD::AND:
case ISD::OR: {
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
if (!C) return false;
if (Op.getOpcode() == ISD::XOR &&
(C->getAPIntValue() | (~Demanded)).isAllOnesValue())
return false;
// if we can expand it to have all bits set, do it
if (C->getAPIntValue().intersects(~Demanded)) {
EVT VT = Op.getValueType();
SDValue New = DAG.getNode(Op.getOpcode(), dl, VT, Op.getOperand(0),
DAG.getConstant(Demanded &
C->getAPIntValue(),
VT));
return CombineTo(Op, New);
}
break;
}
}
return false;
}
/// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the
/// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening
/// cast, but it could be generalized for targets with other types of
/// implicit widening casts.
bool
TargetLowering::TargetLoweringOpt::ShrinkDemandedOp(SDValue Op,
unsigned BitWidth,
const APInt &Demanded,
DebugLoc dl) {
assert(Op.getNumOperands() == 2 &&
"ShrinkDemandedOp only supports binary operators!");
assert(Op.getNode()->getNumValues() == 1 &&
"ShrinkDemandedOp only supports nodes with one result!");
// Don't do this if the node has another user, which may require the
// full value.
if (!Op.getNode()->hasOneUse())
return false;
// Search for the smallest integer type with free casts to and from
// Op's type. For expedience, just check power-of-2 integer types.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned SmallVTBits = BitWidth - Demanded.countLeadingZeros();
if (!isPowerOf2_32(SmallVTBits))
SmallVTBits = NextPowerOf2(SmallVTBits);
for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) {
EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), SmallVTBits);
if (TLI.isTruncateFree(Op.getValueType(), SmallVT) &&
TLI.isZExtFree(SmallVT, Op.getValueType())) {
// We found a type with free casts.
SDValue X = DAG.getNode(Op.getOpcode(), dl, SmallVT,
DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
Op.getNode()->getOperand(0)),
DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
Op.getNode()->getOperand(1)));
SDValue Z = DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), X);
return CombineTo(Op, Z);
}
}
return false;
}
/// SimplifyDemandedBits - Look at Op. At this point, we know that only the
/// DemandedMask bits of the result of Op are ever used downstream. If we can
/// use this information to simplify Op, create a new simplified DAG node and
/// return true, returning the original and new nodes in Old and New. Otherwise,
/// analyze the expression and return a mask of KnownOne and KnownZero bits for
/// the expression (used to simplify the caller). The KnownZero/One bits may
/// only be accurate for those bits in the DemandedMask.
bool TargetLowering::SimplifyDemandedBits(SDValue Op,
const APInt &DemandedMask,
APInt &KnownZero,
APInt &KnownOne,
TargetLoweringOpt &TLO,
unsigned Depth) const {
unsigned BitWidth = DemandedMask.getBitWidth();
assert(Op.getValueType().getScalarType().getSizeInBits() == BitWidth &&
"Mask size mismatches value type size!");
APInt NewMask = DemandedMask;
DebugLoc dl = Op.getDebugLoc();
// Don't know anything.
KnownZero = KnownOne = APInt(BitWidth, 0);
// Other users may use these bits.
if (!Op.getNode()->hasOneUse()) {
if (Depth != 0) {
// If not at the root, Just compute the KnownZero/KnownOne bits to
// simplify things downstream.
TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
return false;
}
// If this is the root being simplified, allow it to have multiple uses,
// just set the NewMask to all bits.
NewMask = APInt::getAllOnesValue(BitWidth);
} else if (DemandedMask == 0) {
// Not demanding any bits from Op.
if (Op.getOpcode() != ISD::UNDEF)
return TLO.CombineTo(Op, TLO.DAG.getUNDEF(Op.getValueType()));
return false;
} else if (Depth == 6) { // Limit search depth.
return false;
}
APInt KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut;
switch (Op.getOpcode()) {
case ISD::Constant:
// We know all of the bits for a constant!
KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue() & NewMask;
KnownZero = ~KnownOne & NewMask;
return false; // Don't fall through, will infinitely loop.
case ISD::AND:
// If the RHS is a constant, check to see if the LHS would be zero without
// using the bits from the RHS. Below, we use knowledge about the RHS to
// simplify the LHS, here we're using information from the LHS to simplify
// the RHS.
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
APInt LHSZero, LHSOne;
// Do not increment Depth here; that can cause an infinite loop.
TLO.DAG.ComputeMaskedBits(Op.getOperand(0), NewMask,
LHSZero, LHSOne, Depth);
// If the LHS already has zeros where RHSC does, this and is dead.
if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
// If any of the set bits in the RHS are known zero on the LHS, shrink
// the constant.
if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & NewMask))
return true;
}
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
if (SimplifyDemandedBits(Op.getOperand(0), ~KnownZero & NewMask,
KnownZero2, KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If all of the demanded bits are known one on one side, return the other.
// These bits cannot contribute to the result of the 'and'.
if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
return TLO.CombineTo(Op, Op.getOperand(1));
// If all of the demanded bits in the inputs are known zeros, return zero.
if ((NewMask & (KnownZero|KnownZero2)) == NewMask)
return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType()));
// If the RHS is a constant, see if we can simplify it.
if (TLO.ShrinkDemandedConstant(Op, ~KnownZero2 & NewMask))
return true;
// If the operation can be done in a smaller type, do so.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
// Output known-1 bits are only known if set in both the LHS & RHS.
KnownOne &= KnownOne2;
// Output known-0 are known to be clear if zero in either the LHS | RHS.
KnownZero |= KnownZero2;
break;
case ISD::OR:
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask,
KnownZero2, KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If all of the demanded bits are known zero on one side, return the other.
// These bits cannot contribute to the result of the 'or'.
if ((NewMask & ~KnownOne2 & KnownZero) == (~KnownOne2 & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask))
return TLO.CombineTo(Op, Op.getOperand(1));
// If all of the potentially set bits on one side are known to be set on
// the other side, just use the 'other' side.
if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
return TLO.CombineTo(Op, Op.getOperand(1));
// If the RHS is a constant, see if we can simplify it.
if (TLO.ShrinkDemandedConstant(Op, NewMask))
return true;
// If the operation can be done in a smaller type, do so.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
// Output known-0 bits are only known if clear in both the LHS & RHS.
KnownZero &= KnownZero2;
// Output known-1 are known to be set if set in either the LHS | RHS.
KnownOne |= KnownOne2;
break;
case ISD::XOR:
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
if (SimplifyDemandedBits(Op.getOperand(0), NewMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If all of the demanded bits are known zero on one side, return the other.
// These bits cannot contribute to the result of the 'xor'.
if ((KnownZero & NewMask) == NewMask)
return TLO.CombineTo(Op, Op.getOperand(0));
if ((KnownZero2 & NewMask) == NewMask)
return TLO.CombineTo(Op, Op.getOperand(1));
// If the operation can be done in a smaller type, do so.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
// If all of the unknown bits are known to be zero on one side or the other
// (but not both) turn this into an *inclusive* or.
// e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
if ((NewMask & ~KnownZero & ~KnownZero2) == 0)
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(),
Op.getOperand(0),
Op.getOperand(1)));
// Output known-0 bits are known if clear or set in both the LHS & RHS.
KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
// Output known-1 are known to be set if set in only one of the LHS, RHS.
KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
// If all of the demanded bits on one side are known, and all of the set
// bits on that side are also known to be set on the other side, turn this
// into an AND, as we know the bits will be cleared.
// e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known
if ((KnownOne & KnownOne2) == KnownOne) {
EVT VT = Op.getValueType();
SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT);
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT,
Op.getOperand(0), ANDC));
}
}
// If the RHS is a constant, see if we can simplify it.
// for XOR, we prefer to force bits to 1 if they will make a -1.
// if we can't force bits, try to shrink constant
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
APInt Expanded = C->getAPIntValue() | (~NewMask);
// if we can expand it to have all bits set, do it
if (Expanded.isAllOnesValue()) {
if (Expanded != C->getAPIntValue()) {
EVT VT = Op.getValueType();
SDValue New = TLO.DAG.getNode(Op.getOpcode(), dl,VT, Op.getOperand(0),
TLO.DAG.getConstant(Expanded, VT));
return TLO.CombineTo(Op, New);
}
// if it already has all the bits set, nothing to change
// but don't shrink either!
} else if (TLO.ShrinkDemandedConstant(Op, NewMask)) {
return true;
}
}
KnownZero = KnownZeroOut;
KnownOne = KnownOneOut;
break;
case ISD::SELECT:
if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If the operands are constants, see if we can simplify them.
if (TLO.ShrinkDemandedConstant(Op, NewMask))
return true;
// Only known if known in both the LHS and RHS.
KnownOne &= KnownOne2;
KnownZero &= KnownZero2;
break;
case ISD::SELECT_CC:
if (SimplifyDemandedBits(Op.getOperand(3), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If the operands are constants, see if we can simplify them.
if (TLO.ShrinkDemandedConstant(Op, NewMask))
return true;
// Only known if known in both the LHS and RHS.
KnownOne &= KnownOne2;
KnownZero &= KnownZero2;
break;
case ISD::SHL:
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
unsigned ShAmt = SA->getZExtValue();
SDValue InOp = Op.getOperand(0);
// If the shift count is an invalid immediate, don't do anything.
if (ShAmt >= BitWidth)
break;
// If this is ((X >>u C1) << ShAmt), see if we can simplify this into a
// single shift. We can do this if the bottom bits (which are shifted
// out) are never demanded.
if (InOp.getOpcode() == ISD::SRL &&
isa<ConstantSDNode>(InOp.getOperand(1))) {
if (ShAmt && (NewMask & APInt::getLowBitsSet(BitWidth, ShAmt)) == 0) {
unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
unsigned Opc = ISD::SHL;
int Diff = ShAmt-C1;
if (Diff < 0) {
Diff = -Diff;
Opc = ISD::SRL;
}
SDValue NewSA =
TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
EVT VT = Op.getValueType();
return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
InOp.getOperand(0), NewSA));
}
}
if (SimplifyDemandedBits(InOp, NewMask.lshr(ShAmt),
KnownZero, KnownOne, TLO, Depth+1))
return true;
// Convert (shl (anyext x, c)) to (anyext (shl x, c)) if the high bits
// are not demanded. This will likely allow the anyext to be folded away.
if (InOp.getNode()->getOpcode() == ISD::ANY_EXTEND) {
SDValue InnerOp = InOp.getNode()->getOperand(0);
EVT InnerVT = InnerOp.getValueType();
if ((APInt::getHighBitsSet(BitWidth,
BitWidth - InnerVT.getSizeInBits()) &
DemandedMask) == 0 &&
isTypeDesirableForOp(ISD::SHL, InnerVT)) {
EVT ShTy = getShiftAmountTy(InnerVT);
if (!APInt(BitWidth, ShAmt).isIntN(ShTy.getSizeInBits()))
ShTy = InnerVT;
SDValue NarrowShl =
TLO.DAG.getNode(ISD::SHL, dl, InnerVT, InnerOp,
TLO.DAG.getConstant(ShAmt, ShTy));
return
TLO.CombineTo(Op,
TLO.DAG.getNode(ISD::ANY_EXTEND, dl, Op.getValueType(),
NarrowShl));
}
}
KnownZero <<= SA->getZExtValue();
KnownOne <<= SA->getZExtValue();
// low bits known zero.
KnownZero |= APInt::getLowBitsSet(BitWidth, SA->getZExtValue());
}
break;
case ISD::SRL:
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
EVT VT = Op.getValueType();
unsigned ShAmt = SA->getZExtValue();
unsigned VTSize = VT.getSizeInBits();
SDValue InOp = Op.getOperand(0);
// If the shift count is an invalid immediate, don't do anything.
if (ShAmt >= BitWidth)
break;
// If this is ((X << C1) >>u ShAmt), see if we can simplify this into a
// single shift. We can do this if the top bits (which are shifted out)
// are never demanded.
if (InOp.getOpcode() == ISD::SHL &&
isa<ConstantSDNode>(InOp.getOperand(1))) {
if (ShAmt && (NewMask & APInt::getHighBitsSet(VTSize, ShAmt)) == 0) {
unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
unsigned Opc = ISD::SRL;
int Diff = ShAmt-C1;
if (Diff < 0) {
Diff = -Diff;
Opc = ISD::SHL;
}
SDValue NewSA =
TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
InOp.getOperand(0), NewSA));
}
}
// Compute the new bits that are at the top now.
if (SimplifyDemandedBits(InOp, (NewMask << ShAmt),
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero = KnownZero.lshr(ShAmt);
KnownOne = KnownOne.lshr(ShAmt);
APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
KnownZero |= HighBits; // High bits known zero.
}
break;
case ISD::SRA:
// If this is an arithmetic shift right and only the low-bit is set, we can
// always convert this into a logical shr, even if the shift amount is
// variable. The low bit of the shift cannot be an input sign bit unless
// the shift amount is >= the size of the datatype, which is undefined.
if (DemandedMask == 1)
return TLO.CombineTo(Op,
TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(),
Op.getOperand(0), Op.getOperand(1)));
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
EVT VT = Op.getValueType();
unsigned ShAmt = SA->getZExtValue();
// If the shift count is an invalid immediate, don't do anything.
if (ShAmt >= BitWidth)
break;
APInt InDemandedMask = (NewMask << ShAmt);
// If any of the demanded bits are produced by the sign extension, we also
// demand the input sign bit.
APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
if (HighBits.intersects(NewMask))
InDemandedMask |= APInt::getSignBit(VT.getScalarType().getSizeInBits());
if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero = KnownZero.lshr(ShAmt);
KnownOne = KnownOne.lshr(ShAmt);
// Handle the sign bit, adjusted to where it is now in the mask.
APInt SignBit = APInt::getSignBit(BitWidth).lshr(ShAmt);
// If the input sign bit is known to be zero, or if none of the top bits
// are demanded, turn this into an unsigned shift right.
if (KnownZero.intersects(SignBit) || (HighBits & ~NewMask) == HighBits) {
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT,
Op.getOperand(0),
Op.getOperand(1)));
} else if (KnownOne.intersects(SignBit)) { // New bits are known one.
KnownOne |= HighBits;
}
}
break;
case ISD::SIGN_EXTEND_INREG: {
EVT EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
// Sign extension. Compute the demanded bits in the result that are not
// present in the input.
APInt NewBits =
APInt::getHighBitsSet(BitWidth,
BitWidth - EVT.getScalarType().getSizeInBits());
// If none of the extended bits are demanded, eliminate the sextinreg.
if ((NewBits & NewMask) == 0)
return TLO.CombineTo(Op, Op.getOperand(0));
APInt InSignBit =
APInt::getSignBit(EVT.getScalarType().getSizeInBits()).zext(BitWidth);
APInt InputDemandedBits =
APInt::getLowBitsSet(BitWidth,
EVT.getScalarType().getSizeInBits()) &
NewMask;
// Since the sign extended bits are demanded, we know that the sign
// bit is demanded.
InputDemandedBits |= InSignBit;
if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
// If the sign bit of the input is known set or clear, then we know the
// top bits of the result.
// If the input sign bit is known zero, convert this into a zero extension.
if (KnownZero.intersects(InSignBit))
return TLO.CombineTo(Op,
TLO.DAG.getZeroExtendInReg(Op.getOperand(0),dl,EVT));
if (KnownOne.intersects(InSignBit)) { // Input sign bit known set
KnownOne |= NewBits;
KnownZero &= ~NewBits;
} else { // Input sign bit unknown
KnownZero &= ~NewBits;
KnownOne &= ~NewBits;
}
break;
}
case ISD::ZERO_EXTEND: {
unsigned OperandBitWidth =
Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
APInt InMask = NewMask.trunc(OperandBitWidth);
// If none of the top bits are demanded, convert this into an any_extend.
APInt NewBits =
APInt::getHighBitsSet(BitWidth, BitWidth - OperandBitWidth) & NewMask;
if (!NewBits.intersects(NewMask))
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
Op.getValueType(),
Op.getOperand(0)));
if (SimplifyDemandedBits(Op.getOperand(0), InMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero = KnownZero.zext(BitWidth);
KnownOne = KnownOne.zext(BitWidth);
KnownZero |= NewBits;
break;
}
case ISD::SIGN_EXTEND: {
EVT InVT = Op.getOperand(0).getValueType();
unsigned InBits = InVT.getScalarType().getSizeInBits();
APInt InMask = APInt::getLowBitsSet(BitWidth, InBits);
APInt InSignBit = APInt::getBitsSet(BitWidth, InBits - 1, InBits);
APInt NewBits = ~InMask & NewMask;
// If none of the top bits are demanded, convert this into an any_extend.
if (NewBits == 0)
return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
Op.getValueType(),
Op.getOperand(0)));
// Since some of the sign extended bits are demanded, we know that the sign
// bit is demanded.
APInt InDemandedBits = InMask & NewMask;
InDemandedBits |= InSignBit;
InDemandedBits = InDemandedBits.trunc(InBits);
if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
KnownOne, TLO, Depth+1))
return true;
KnownZero = KnownZero.zext(BitWidth);
KnownOne = KnownOne.zext(BitWidth);
// If the sign bit is known zero, convert this to a zero extend.
if (KnownZero.intersects(InSignBit))
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND, dl,
Op.getValueType(),
Op.getOperand(0)));
// If the sign bit is known one, the top bits match.
if (KnownOne.intersects(InSignBit)) {
KnownOne |= NewBits;
KnownZero &= ~NewBits;
} else { // Otherwise, top bits aren't known.
KnownOne &= ~NewBits;
KnownZero &= ~NewBits;
}
break;
}
case ISD::ANY_EXTEND: {
unsigned OperandBitWidth =
Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
APInt InMask = NewMask.trunc(OperandBitWidth);
if (SimplifyDemandedBits(Op.getOperand(0), InMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero = KnownZero.zext(BitWidth);
KnownOne = KnownOne.zext(BitWidth);
break;
}
case ISD::TRUNCATE: {
// Simplify the input, using demanded bit information, and compute the known
// zero/one bits live out.
unsigned OperandBitWidth =
Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
APInt TruncMask = NewMask.zext(OperandBitWidth);
if (SimplifyDemandedBits(Op.getOperand(0), TruncMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
KnownZero = KnownZero.trunc(BitWidth);
KnownOne = KnownOne.trunc(BitWidth);
// If the input is only used by this truncate, see if we can shrink it based
// on the known demanded bits.
if (Op.getOperand(0).getNode()->hasOneUse()) {
SDValue In = Op.getOperand(0);
switch (In.getOpcode()) {
default: break;
case ISD::SRL:
// Shrink SRL by a constant if none of the high bits shifted in are
// demanded.
if (TLO.LegalTypes() &&
!isTypeDesirableForOp(ISD::SRL, Op.getValueType()))
// Do not turn (vt1 truncate (vt2 srl)) into (vt1 srl) if vt1 is
// undesirable.
break;
ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1));
if (!ShAmt)
break;
APInt HighBits = APInt::getHighBitsSet(OperandBitWidth,
OperandBitWidth - BitWidth);
HighBits = HighBits.lshr(ShAmt->getZExtValue()).trunc(BitWidth);
if (ShAmt->getZExtValue() < BitWidth && !(HighBits & NewMask)) {
// None of the shifted in bits are needed. Add a truncate of the
// shift input, then shift it.
SDValue NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE, dl,
Op.getValueType(),
In.getOperand(0));
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl,
Op.getValueType(),
NewTrunc,
In.getOperand(1)));
}
break;
}
}
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
break;
}
case ISD::AssertZext: {
// Demand all the bits of the input that are demanded in the output.
// The low bits are obvious; the high bits are demanded because we're
// asserting that they're zero here.
if (SimplifyDemandedBits(Op.getOperand(0), NewMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
EVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
APInt InMask = APInt::getLowBitsSet(BitWidth,
VT.getSizeInBits());
KnownZero |= ~InMask & NewMask;
break;
}
case ISD::BITCAST:
#if 0
// If this is an FP->Int bitcast and if the sign bit is the only thing that
// is demanded, turn this into a FGETSIGN.
if (NewMask == EVT::getIntegerVTSignBit(Op.getValueType()) &&
MVT::isFloatingPoint(Op.getOperand(0).getValueType()) &&
!MVT::isVector(Op.getOperand(0).getValueType())) {
// Only do this xform if FGETSIGN is valid or if before legalize.
if (!TLO.AfterLegalize ||
isOperationLegal(ISD::FGETSIGN, Op.getValueType())) {
// Make a FGETSIGN + SHL to move the sign bit into the appropriate
// place. We expect the SHL to be eliminated by other optimizations.
SDValue Sign = TLO.DAG.getNode(ISD::FGETSIGN, Op.getValueType(),
Op.getOperand(0));
unsigned ShVal = Op.getValueType().getSizeInBits()-1;
SDValue ShAmt = TLO.DAG.getConstant(ShVal, getShiftAmountTy());
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, Op.getValueType(),
Sign, ShAmt));
}
}
#endif
break;
case ISD::ADD:
case ISD::MUL:
case ISD::SUB: {
// Add, Sub, and Mul don't demand any bits in positions beyond that
// of the highest bit demanded of them.
APInt LoMask = APInt::getLowBitsSet(BitWidth,
BitWidth - NewMask.countLeadingZeros());
if (SimplifyDemandedBits(Op.getOperand(0), LoMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
if (SimplifyDemandedBits(Op.getOperand(1), LoMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
// See if the operation should be performed at a smaller bit width.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
}
// FALL THROUGH
default:
// Just use ComputeMaskedBits to compute output bits.
TLO.DAG.ComputeMaskedBits(Op, NewMask, KnownZero, KnownOne, Depth);
break;
}
// If we know the value of all of the demanded bits, return this as a
// constant.
if ((NewMask & (KnownZero|KnownOne)) == NewMask)
return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
return false;
}
/// computeMaskedBitsForTargetNode - Determine which of the bits specified
/// in Mask are known to be either zero or one and return them in the
/// KnownZero/KnownOne bitsets.
void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
const APInt &Mask,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth) const {
assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
"Should use MaskedValueIsZero if you don't know whether Op"
" is a target node!");
KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
}
/// ComputeNumSignBitsForTargetNode - This method can be implemented by
/// targets that want to expose additional information about sign bits to the
/// DAG Combiner.
unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
unsigned Depth) const {
assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
"Should use ComputeNumSignBits if you don't know whether Op"
" is a target node!");
return 1;
}
/// ValueHasExactlyOneBitSet - Test if the given value is known to have exactly
/// one bit set. This differs from ComputeMaskedBits in that it doesn't need to
/// determine which bit is set.
///
static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) {
// A left-shift of a constant one will have exactly one bit set, because
// shifting the bit off the end is undefined.
if (Val.getOpcode() == ISD::SHL)
if (ConstantSDNode *C =
dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
if (C->getAPIntValue() == 1)
return true;
// Similarly, a right-shift of a constant sign-bit will have exactly
// one bit set.
if (Val.getOpcode() == ISD::SRL)
if (ConstantSDNode *C =
dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
if (C->getAPIntValue().isSignBit())
return true;
// More could be done here, though the above checks are enough
// to handle some common cases.
// Fall back to ComputeMaskedBits to catch other known cases.
EVT OpVT = Val.getValueType();
unsigned BitWidth = OpVT.getScalarType().getSizeInBits();
APInt Mask = APInt::getAllOnesValue(BitWidth);
APInt KnownZero, KnownOne;
DAG.ComputeMaskedBits(Val, Mask, KnownZero, KnownOne);
return (KnownZero.countPopulation() == BitWidth - 1) &&
(KnownOne.countPopulation() == 1);
}
/// SimplifySetCC - Try to simplify a setcc built with the specified operands
/// and cc. If it is unable to simplify it, return a null SDValue.
SDValue
TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
ISD::CondCode Cond, bool foldBooleans,
DAGCombinerInfo &DCI, DebugLoc dl) const {
SelectionDAG &DAG = DCI.DAG;
LLVMContext &Context = *DAG.getContext();
// These setcc operations always fold.
switch (Cond) {
default: break;
case ISD::SETFALSE:
case ISD::SETFALSE2: return DAG.getConstant(0, VT);
case ISD::SETTRUE:
case ISD::SETTRUE2: return DAG.getConstant(1, VT);
}
if (isa<ConstantSDNode>(N0.getNode())) {
// Ensure that the constant occurs on the RHS, and fold constant
// comparisons.
return DAG.getSetCC(dl, VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
}
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) {
const APInt &C1 = N1C->getAPIntValue();
// If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an
// equality comparison, then we're just comparing whether X itself is
// zero.
if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) &&
N0.getOperand(0).getOpcode() == ISD::CTLZ &&
N0.getOperand(1).getOpcode() == ISD::Constant) {
const APInt &ShAmt
= cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
ShAmt == Log2_32(N0.getValueType().getSizeInBits())) {
if ((C1 == 0) == (Cond == ISD::SETEQ)) {
// (srl (ctlz x), 5) == 0 -> X != 0
// (srl (ctlz x), 5) != 1 -> X != 0
Cond = ISD::SETNE;
} else {
// (srl (ctlz x), 5) != 0 -> X == 0
// (srl (ctlz x), 5) == 1 -> X == 0
Cond = ISD::SETEQ;
}
SDValue Zero = DAG.getConstant(0, N0.getValueType());
return DAG.getSetCC(dl, VT, N0.getOperand(0).getOperand(0),
Zero, Cond);
}
}
SDValue CTPOP = N0;
// Look through truncs that don't change the value of a ctpop.
if (N0.hasOneUse() && N0.getOpcode() == ISD::TRUNCATE)
CTPOP = N0.getOperand(0);
if (CTPOP.hasOneUse() && CTPOP.getOpcode() == ISD::CTPOP &&
(N0 == CTPOP || N0.getValueType().getSizeInBits() >
Log2_32_Ceil(CTPOP.getValueType().getSizeInBits()))) {
EVT CTVT = CTPOP.getValueType();
SDValue CTOp = CTPOP.getOperand(0);
// (ctpop x) u< 2 -> (x & x-1) == 0
// (ctpop x) u> 1 -> (x & x-1) != 0
if ((Cond == ISD::SETULT && C1 == 2) || (Cond == ISD::SETUGT && C1 == 1)){
SDValue Sub = DAG.getNode(ISD::SUB, dl, CTVT, CTOp,
DAG.getConstant(1, CTVT));
SDValue And = DAG.getNode(ISD::AND, dl, CTVT, CTOp, Sub);
ISD::CondCode CC = Cond == ISD::SETULT ? ISD::SETEQ : ISD::SETNE;
return DAG.getSetCC(dl, VT, And, DAG.getConstant(0, CTVT), CC);
}
// TODO: (ctpop x) == 1 -> x && (x & x-1) == 0 iff ctpop is illegal.
}
// If the LHS is '(and load, const)', the RHS is 0,
// the test is for equality or unsigned, and all 1 bits of the const are
// in the same partial word, see if we can shorten the load.
if (DCI.isBeforeLegalize() &&
N0.getOpcode() == ISD::AND && C1 == 0 &&
N0.getNode()->hasOneUse() &&
isa<LoadSDNode>(N0.getOperand(0)) &&
N0.getOperand(0).getNode()->hasOneUse() &&
isa<ConstantSDNode>(N0.getOperand(1))) {
LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0));
APInt bestMask;
unsigned bestWidth = 0, bestOffset = 0;
if (!Lod->isVolatile() && Lod->isUnindexed()) {
unsigned origWidth = N0.getValueType().getSizeInBits();
unsigned maskWidth = origWidth;
// We can narrow (e.g.) 16-bit extending loads on 32-bit target to
// 8 bits, but have to be careful...
if (Lod->getExtensionType() != ISD::NON_EXTLOAD)
origWidth = Lod->getMemoryVT().getSizeInBits();
const APInt &Mask =
cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
for (unsigned width = origWidth / 2; width>=8; width /= 2) {
APInt newMask = APInt::getLowBitsSet(maskWidth, width);
for (unsigned offset=0; offset<origWidth/width; offset++) {
if ((newMask & Mask) == Mask) {
if (!TD->isLittleEndian())
bestOffset = (origWidth/width - offset - 1) * (width/8);
else
bestOffset = (uint64_t)offset * (width/8);
bestMask = Mask.lshr(offset * (width/8) * 8);
bestWidth = width;
break;
}
newMask = newMask << width;
}
}
}
if (bestWidth) {
EVT newVT = EVT::getIntegerVT(Context, bestWidth);
if (newVT.isRound()) {
EVT PtrType = Lod->getOperand(1).getValueType();
SDValue Ptr = Lod->getBasePtr();
if (bestOffset != 0)
Ptr = DAG.getNode(ISD::ADD, dl, PtrType, Lod->getBasePtr(),
DAG.getConstant(bestOffset, PtrType));
unsigned NewAlign = MinAlign(Lod->getAlignment(), bestOffset);
SDValue NewLoad = DAG.getLoad(newVT, dl, Lod->getChain(), Ptr,
Lod->getPointerInfo().getWithOffset(bestOffset),
false, false, NewAlign);
return DAG.getSetCC(dl, VT,
DAG.getNode(ISD::AND, dl, newVT, NewLoad,
DAG.getConstant(bestMask.trunc(bestWidth),
newVT)),
DAG.getConstant(0LL, newVT), Cond);
}
}
}
// If the LHS is a ZERO_EXTEND, perform the comparison on the input.
if (N0.getOpcode() == ISD::ZERO_EXTEND) {
unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits();
// If the comparison constant has bits in the upper part, the
// zero-extended value could never match.
if (C1.intersects(APInt::getHighBitsSet(C1.getBitWidth(),
C1.getBitWidth() - InSize))) {
switch (Cond) {
case ISD::SETUGT:
case ISD::SETUGE:
case ISD::SETEQ: return DAG.getConstant(0, VT);
case ISD::SETULT:
case ISD::SETULE:
case ISD::SETNE: return DAG.getConstant(1, VT);
case ISD::SETGT:
case ISD::SETGE:
// True if the sign bit of C1 is set.
return DAG.getConstant(C1.isNegative(), VT);
case ISD::SETLT:
case ISD::SETLE:
// True if the sign bit of C1 isn't set.
return DAG.getConstant(C1.isNonNegative(), VT);
default:
break;
}
}
// Otherwise, we can perform the comparison with the low bits.
switch (Cond) {
case ISD::SETEQ:
case ISD::SETNE:
case ISD::SETUGT:
case ISD::SETUGE:
case ISD::SETULT:
case ISD::SETULE: {
EVT newVT = N0.getOperand(0).getValueType();
if (DCI.isBeforeLegalizeOps() ||
(isOperationLegal(ISD::SETCC, newVT) &&
getCondCodeAction(Cond, newVT)==Legal))
return DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(C1.trunc(InSize), newVT),
Cond);
break;
}
default:
break; // todo, be more careful with signed comparisons
}
} else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
(Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
EVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits();
EVT ExtDstTy = N0.getValueType();
unsigned ExtDstTyBits = ExtDstTy.getSizeInBits();
// If the constant doesn't fit into the number of bits for the source of
// the sign extension, it is impossible for both sides to be equal.
if (C1.getMinSignedBits() > ExtSrcTyBits)
return DAG.getConstant(Cond == ISD::SETNE, VT);
SDValue ZextOp;
EVT Op0Ty = N0.getOperand(0).getValueType();
if (Op0Ty == ExtSrcTy) {
ZextOp = N0.getOperand(0);
} else {
APInt Imm = APInt::getLowBitsSet(ExtDstTyBits, ExtSrcTyBits);
ZextOp = DAG.getNode(ISD::AND, dl, Op0Ty, N0.getOperand(0),
DAG.getConstant(Imm, Op0Ty));
}
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(ZextOp.getNode());
// Otherwise, make this a use of a zext.
return DAG.getSetCC(dl, VT, ZextOp,
DAG.getConstant(C1 & APInt::getLowBitsSet(
ExtDstTyBits,
ExtSrcTyBits),
ExtDstTy),
Cond);
} else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) &&
(Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
// SETCC (SETCC), [0|1], [EQ|NE] -> SETCC
if (N0.getOpcode() == ISD::SETCC &&
isTypeLegal(VT) && VT.bitsLE(N0.getValueType())) {
bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getAPIntValue() != 1);
if (TrueWhenTrue)
return DAG.getNode(ISD::TRUNCATE, dl, VT, N0);
// Invert the condition.
ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
CC = ISD::getSetCCInverse(CC,
N0.getOperand(0).getValueType().isInteger());
return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
}
if ((N0.getOpcode() == ISD::XOR ||
(N0.getOpcode() == ISD::AND &&
N0.getOperand(0).getOpcode() == ISD::XOR &&
N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
isa<ConstantSDNode>(N0.getOperand(1)) &&
cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue() == 1) {
// If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We
// can only do this if the top bits are known zero.
unsigned BitWidth = N0.getValueSizeInBits();
if (DAG.MaskedValueIsZero(N0,
APInt::getHighBitsSet(BitWidth,
BitWidth-1))) {
// Okay, get the un-inverted input value.
SDValue Val;
if (N0.getOpcode() == ISD::XOR)
Val = N0.getOperand(0);
else {
assert(N0.getOpcode() == ISD::AND &&
N0.getOperand(0).getOpcode() == ISD::XOR);
// ((X^1)&1)^1 -> X & 1
Val = DAG.getNode(ISD::AND, dl, N0.getValueType(),
N0.getOperand(0).getOperand(0),
N0.getOperand(1));
}
return DAG.getSetCC(dl, VT, Val, N1,
Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
}
} else if (N1C->getAPIntValue() == 1 &&
(VT == MVT::i1 ||
getBooleanContents() == ZeroOrOneBooleanContent)) {
SDValue Op0 = N0;
if (Op0.getOpcode() == ISD::TRUNCATE)
Op0 = Op0.getOperand(0);
if ((Op0.getOpcode() == ISD::XOR) &&
Op0.getOperand(0).getOpcode() == ISD::SETCC &&
Op0.getOperand(1).getOpcode() == ISD::SETCC) {
// (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc)
Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
Cond);
} else if (Op0.getOpcode() == ISD::AND &&
isa<ConstantSDNode>(Op0.getOperand(1)) &&
cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
// If this is (X&1) == / != 1, normalize it to (X&1) != / == 0.
if (Op0.getValueType().bitsGT(VT))
Op0 = DAG.getNode(ISD::AND, dl, VT,
DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)),
DAG.getConstant(1, VT));
else if (Op0.getValueType().bitsLT(VT))
Op0 = DAG.getNode(ISD::AND, dl, VT,
DAG.getNode(ISD::ANY_EXTEND, dl, VT, Op0.getOperand(0)),
DAG.getConstant(1, VT));
return DAG.getSetCC(dl, VT, Op0,
DAG.getConstant(0, Op0.getValueType()),
Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
}
}
}
APInt MinVal, MaxVal;
unsigned OperandBitSize = N1C->getValueType(0).getSizeInBits();
if (ISD::isSignedIntSetCC(Cond)) {
MinVal = APInt::getSignedMinValue(OperandBitSize);
MaxVal = APInt::getSignedMaxValue(OperandBitSize);
} else {
MinVal = APInt::getMinValue(OperandBitSize);
MaxVal = APInt::getMaxValue(OperandBitSize);
}
// Canonicalize GE/LE comparisons to use GT/LT comparisons.
if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
// X >= C0 --> X > (C0-1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(C1-1, N1.getValueType()),
(Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
}
if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
// X <= C0 --> X < (C0+1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(C1+1, N1.getValueType()),
(Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
}
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
return DAG.getConstant(0, VT); // X < MIN --> false
if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal)
return DAG.getConstant(1, VT); // X >= MIN --> true
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal)
return DAG.getConstant(0, VT); // X > MAX --> false
if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal)
return DAG.getConstant(1, VT); // X <= MAX --> true
// Canonicalize setgt X, Min --> setne X, Min
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
// Canonicalize setlt X, Max --> setne X, Max
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
// If we have setult X, 1, turn it into seteq X, 0
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(MinVal, N0.getValueType()),
ISD::SETEQ);
// If we have setugt X, Max-1, turn it into seteq X, Max
else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(MaxVal, N0.getValueType()),
ISD::SETEQ);
// If we have "setcc X, C0", check to see if we can shrink the immediate
// by changing cc.
// SETUGT X, SINTMAX -> SETLT X, 0
if (Cond == ISD::SETUGT &&
C1 == APInt::getSignedMaxValue(OperandBitSize))
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(0, N1.getValueType()),
ISD::SETLT);
// SETULT X, SINTMIN -> SETGT X, -1
if (Cond == ISD::SETULT &&
C1 == APInt::getSignedMinValue(OperandBitSize)) {
SDValue ConstMinusOne =
DAG.getConstant(APInt::getAllOnesValue(OperandBitSize),
N1.getValueType());
return DAG.getSetCC(dl, VT, N0, ConstMinusOne, ISD::SETGT);
}
// Fold bit comparisons when we can.
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
(VT == N0.getValueType() ||
(isTypeLegal(VT) && VT.bitsLE(N0.getValueType()))) &&
N0.getOpcode() == ISD::AND)
if (ConstantSDNode *AndRHS =
dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
EVT ShiftTy = DCI.isBeforeLegalize() ?
getPointerTy() : getShiftAmountTy(N0.getValueType());
if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
// Perform the xform if the AND RHS is a single bit.
if (AndRHS->getAPIntValue().isPowerOf2()) {
return DAG.getNode(ISD::TRUNCATE, dl, VT,
DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0,
DAG.getConstant(AndRHS->getAPIntValue().logBase2(), ShiftTy)));
}
} else if (Cond == ISD::SETEQ && C1 == AndRHS->getAPIntValue()) {
// (X & 8) == 8 --> (X & 8) >> 3
// Perform the xform if C1 is a single bit.
if (C1.isPowerOf2()) {
return DAG.getNode(ISD::TRUNCATE, dl, VT,
DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0,
DAG.getConstant(C1.logBase2(), ShiftTy)));
}
}
}
}
if (isa<ConstantFPSDNode>(N0.getNode())) {
// Constant fold or commute setcc.
SDValue O = DAG.FoldSetCC(VT, N0, N1, Cond, dl);
if (O.getNode()) return O;
} else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.getNode())) {
// If the RHS of an FP comparison is a constant, simplify it away in
// some cases.
if (CFP->getValueAPF().isNaN()) {
// If an operand is known to be a nan, we can fold it.
switch (ISD::getUnorderedFlavor(Cond)) {
default: llvm_unreachable("Unknown flavor!");
case 0: // Known false.
return DAG.getConstant(0, VT);
case 1: // Known true.
return DAG.getConstant(1, VT);
case 2: // Undefined.
return DAG.getUNDEF(VT);
}
}
// Otherwise, we know the RHS is not a NaN. Simplify the node to drop the
// constant if knowing that the operand is non-nan is enough. We prefer to
// have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to
// materialize 0.0.
if (Cond == ISD::SETO || Cond == ISD::SETUO)
return DAG.getSetCC(dl, VT, N0, N0, Cond);
// If the condition is not legal, see if we can find an equivalent one
// which is legal.
if (!isCondCodeLegal(Cond, N0.getValueType())) {
// If the comparison was an awkward floating-point == or != and one of
// the comparison operands is infinity or negative infinity, convert the
// condition to a less-awkward <= or >=.
if (CFP->getValueAPF().isInfinity()) {
if (CFP->getValueAPF().isNegative()) {
if (Cond == ISD::SETOEQ &&
isCondCodeLegal(ISD::SETOLE, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLE);
if (Cond == ISD::SETUEQ &&
isCondCodeLegal(ISD::SETOLE, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULE);
if (Cond == ISD::SETUNE &&
isCondCodeLegal(ISD::SETUGT, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGT);
if (Cond == ISD::SETONE &&
isCondCodeLegal(ISD::SETUGT, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGT);
} else {
if (Cond == ISD::SETOEQ &&
isCondCodeLegal(ISD::SETOGE, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGE);
if (Cond == ISD::SETUEQ &&
isCondCodeLegal(ISD::SETOGE, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGE);
if (Cond == ISD::SETUNE &&
isCondCodeLegal(ISD::SETULT, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULT);
if (Cond == ISD::SETONE &&
isCondCodeLegal(ISD::SETULT, N0.getValueType()))
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLT);
}
}
}
}
if (N0 == N1) {
// We can always fold X == X for integer setcc's.
if (N0.getValueType().isInteger())
return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
unsigned UOF = ISD::getUnorderedFlavor(Cond);
if (UOF == 2) // FP operators that are undefined on NaNs.
return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
return DAG.getConstant(UOF, VT);
// Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
// if it is not already.
ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
if (NewCond != Cond)
return DAG.getSetCC(dl, VT, N0, N1, NewCond);
}
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
N0.getValueType().isInteger()) {
if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
N0.getOpcode() == ISD::XOR) {
// Simplify (X+Y) == (X+Z) --> Y == Z
if (N0.getOpcode() == N1.getOpcode()) {
if (N0.getOperand(0) == N1.getOperand(0))
return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(1), Cond);
if (N0.getOperand(1) == N1.getOperand(1))
return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(0), Cond);
if (DAG.isCommutativeBinOp(N0.getOpcode())) {
// If X op Y == Y op X, try other combinations.
if (N0.getOperand(0) == N1.getOperand(1))
return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(0),
Cond);
if (N0.getOperand(1) == N1.getOperand(0))
return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(1),
Cond);
}
}
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
// Turn (X+C1) == C2 --> X == C2-C1
if (N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse()) {
return DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(RHSC->getAPIntValue()-
LHSR->getAPIntValue(),
N0.getValueType()), Cond);
}
// Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
if (N0.getOpcode() == ISD::XOR)
// If we know that all of the inverted bits are zero, don't bother
// performing the inversion.
if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getAPIntValue()))
return
DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(LHSR->getAPIntValue() ^
RHSC->getAPIntValue(),
N0.getValueType()),
Cond);
}
// Turn (C1-X) == C2 --> X == C1-C2
if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
if (N0.getOpcode() == ISD::SUB && N0.getNode()->hasOneUse()) {
return
DAG.getSetCC(dl, VT, N0.getOperand(1),
DAG.getConstant(SUBC->getAPIntValue() -
RHSC->getAPIntValue(),
N0.getValueType()),
Cond);
}
}
}
// Simplify (X+Z) == X --> Z == 0
if (N0.getOperand(0) == N1)
return DAG.getSetCC(dl, VT, N0.getOperand(1),
DAG.getConstant(0, N0.getValueType()), Cond);
if (N0.getOperand(1) == N1) {
if (DAG.isCommutativeBinOp(N0.getOpcode()))
return DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(0, N0.getValueType()), Cond);
else if (N0.getNode()->hasOneUse()) {
assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
// (Z-X) == X --> Z == X<<1
SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(),
N1,
DAG.getConstant(1, getShiftAmountTy(N1.getValueType())));
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(SH.getNode());
return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond);
}
}
}
if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
N1.getOpcode() == ISD::XOR) {
// Simplify X == (X+Z) --> Z == 0
if (N1.getOperand(0) == N0) {
return DAG.getSetCC(dl, VT, N1.getOperand(1),
DAG.getConstant(0, N1.getValueType()), Cond);
} else if (N1.getOperand(1) == N0) {
if (DAG.isCommutativeBinOp(N1.getOpcode())) {
return DAG.getSetCC(dl, VT, N1.getOperand(0),
DAG.getConstant(0, N1.getValueType()), Cond);
} else if (N1.getNode()->hasOneUse()) {
assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
// X == (Z-X) --> X<<1 == Z
SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N0,
DAG.getConstant(1, getShiftAmountTy(N0.getValueType())));
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(SH.getNode());
return DAG.getSetCC(dl, VT, SH, N1.getOperand(0), Cond);
}
}
}
// Simplify x&y == y to x&y != 0 if y has exactly one bit set.
// Note that where y is variable and is known to have at most
// one bit set (for example, if it is z&1) we cannot do this;
// the expressions are not equivalent when y==0.
if (N0.getOpcode() == ISD::AND)
if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) {
if (ValueHasExactlyOneBitSet(N1, DAG)) {
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
SDValue Zero = DAG.getConstant(0, N1.getValueType());
return DAG.getSetCC(dl, VT, N0, Zero, Cond);
}
}
if (N1.getOpcode() == ISD::AND)
if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) {
if (ValueHasExactlyOneBitSet(N0, DAG)) {
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
SDValue Zero = DAG.getConstant(0, N0.getValueType());
return DAG.getSetCC(dl, VT, N1, Zero, Cond);
}
}
}
// Fold away ALL boolean setcc's.
SDValue Temp;
if (N0.getValueType() == MVT::i1 && foldBooleans) {
switch (Cond) {
default: llvm_unreachable("Unknown integer setcc!");
case ISD::SETEQ: // X == Y -> ~(X^Y)
Temp = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
N0 = DAG.getNOT(dl, Temp, MVT::i1);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETNE: // X != Y --> (X^Y)
N0 = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
break;
case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> ~X & Y
case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> ~X & Y
Temp = DAG.getNOT(dl, N0, MVT::i1);
N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N1, Temp);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> ~Y & X
case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> ~Y & X
Temp = DAG.getNOT(dl, N1, MVT::i1);
N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N0, Temp);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> ~X | Y
case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> ~X | Y
Temp = DAG.getNOT(dl, N0, MVT::i1);
N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N1, Temp);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> ~Y | X
case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> ~Y | X
Temp = DAG.getNOT(dl, N1, MVT::i1);
N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N0, Temp);
break;
}
if (VT != MVT::i1) {
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(N0.getNode());
// FIXME: If running after legalize, we probably can't do this.
N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0);
}
return N0;
}
// Could not fold it.
return SDValue();
}
/// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
/// node is a GlobalAddress + offset.
bool TargetLowering::isGAPlusOffset(SDNode *N, const GlobalValue *&GA,
int64_t &Offset) const {
if (isa<GlobalAddressSDNode>(N)) {
GlobalAddressSDNode *GASD = cast<GlobalAddressSDNode>(N);
GA = GASD->getGlobal();
Offset += GASD->getOffset();
return true;
}
if (N->getOpcode() == ISD::ADD) {
SDValue N1 = N->getOperand(0);
SDValue N2 = N->getOperand(1);
if (isGAPlusOffset(N1.getNode(), GA, Offset)) {
ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2);
if (V) {
Offset += V->getSExtValue();
return true;
}
} else if (isGAPlusOffset(N2.getNode(), GA, Offset)) {
ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1);
if (V) {
Offset += V->getSExtValue();
return true;
}
}
}
return false;
}
SDValue TargetLowering::
PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
// Default implementation: no optimization.
return SDValue();
}
//===----------------------------------------------------------------------===//
// Inline Assembler Implementation Methods
//===----------------------------------------------------------------------===//
TargetLowering::ConstraintType
TargetLowering::getConstraintType(const std::string &Constraint) const {
// FIXME: lots more standard ones to handle.
if (Constraint.size() == 1) {
switch (Constraint[0]) {
default: break;
case 'r': return C_RegisterClass;
case 'm': // memory
case 'o': // offsetable
case 'V': // not offsetable
return C_Memory;
case 'i': // Simple Integer or Relocatable Constant
case 'n': // Simple Integer
case 'E': // Floating Point Constant
case 'F': // Floating Point Constant
case 's': // Relocatable Constant
case 'p': // Address.
case 'X': // Allow ANY value.
case 'I': // Target registers.
case 'J':
case 'K':
case 'L':
case 'M':
case 'N':
case 'O':
case 'P':
case '<':
case '>':
return C_Other;
}
}
if (Constraint.size() > 1 && Constraint[0] == '{' &&
Constraint[Constraint.size()-1] == '}')
return C_Register;
return C_Unknown;
}
/// LowerXConstraint - try to replace an X constraint, which matches anything,
/// with another that has more specific requirements based on the type of the
/// corresponding operand.
const char *TargetLowering::LowerXConstraint(EVT ConstraintVT) const{
if (ConstraintVT.isInteger())
return "r";
if (ConstraintVT.isFloatingPoint())
return "f"; // works for many targets
return 0;
}
/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
/// vector. If it is invalid, don't add anything to Ops.
void TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
char ConstraintLetter,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const {
switch (ConstraintLetter) {
default: break;
case 'X': // Allows any operand; labels (basic block) use this.
if (Op.getOpcode() == ISD::BasicBlock) {
Ops.push_back(Op);
return;
}
// fall through
case 'i': // Simple Integer or Relocatable Constant
case 'n': // Simple Integer
case 's': { // Relocatable Constant
// These operands are interested in values of the form (GV+C), where C may
// be folded in as an offset of GV, or it may be explicitly added. Also, it
// is possible and fine if either GV or C are missing.
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
// If we have "(add GV, C)", pull out GV/C
if (Op.getOpcode() == ISD::ADD) {
C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0));
if (C == 0 || GA == 0) {
C = dyn_cast<ConstantSDNode>(Op.getOperand(0));
GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1));
}
if (C == 0 || GA == 0)
C = 0, GA = 0;
}
// If we find a valid operand, map to the TargetXXX version so that the
// value itself doesn't get selected.
if (GA) { // Either &GV or &GV+C
if (ConstraintLetter != 'n') {
int64_t Offs = GA->getOffset();
if (C) Offs += C->getZExtValue();
Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(),
C ? C->getDebugLoc() : DebugLoc(),
Op.getValueType(), Offs));
return;
}
}
if (C) { // just C, no GV.
// Simple constants are not allowed for 's'.
if (ConstraintLetter != 's') {
// gcc prints these as sign extended. Sign extend value to 64 bits
// now; without this it would get ZExt'd later in
// ScheduleDAGSDNodes::EmitNode, which is very generic.
Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(),
MVT::i64));
return;
}
}
break;
}
}
}
std::vector<unsigned> TargetLowering::
getRegClassForInlineAsmConstraint(const std::string &Constraint,
EVT VT) const {
return std::vector<unsigned>();
}
std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
getRegForInlineAsmConstraint(const std::string &Constraint,
EVT VT) const {
if (Constraint[0] != '{')
return std::make_pair(0u, static_cast<TargetRegisterClass*>(0));
assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");
// Remove the braces from around the name.
StringRef RegName(Constraint.data()+1, Constraint.size()-2);
// Figure out which register class contains this reg.
const TargetRegisterInfo *RI = TM.getRegisterInfo();
for (TargetRegisterInfo::regclass_iterator RCI = RI->regclass_begin(),
E = RI->regclass_end(); RCI != E; ++RCI) {
const TargetRegisterClass *RC = *RCI;
// If none of the value types for this register class are valid, we
// can't use it. For example, 64-bit reg classes on 32-bit targets.
bool isLegal = false;
for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end();
I != E; ++I) {
if (isTypeLegal(*I)) {
isLegal = true;
break;
}
}
if (!isLegal) continue;
for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
I != E; ++I) {
if (RegName.equals_lower(RI->getName(*I)))
return std::make_pair(*I, RC);
}
}
return std::make_pair(0u, static_cast<const TargetRegisterClass*>(0));
}
//===----------------------------------------------------------------------===//
// Constraint Selection.
/// isMatchingInputConstraint - Return true of this is an input operand that is
/// a matching constraint like "4".
bool TargetLowering::AsmOperandInfo::isMatchingInputConstraint() const {
assert(!ConstraintCode.empty() && "No known constraint!");
return isdigit(ConstraintCode[0]);
}
/// getMatchedOperand - If this is an input matching constraint, this method
/// returns the output operand it matches.
unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const {
assert(!ConstraintCode.empty() && "No known constraint!");
return atoi(ConstraintCode.c_str());
}
/// ParseConstraints - Split up the constraint string from the inline
/// assembly value into the specific constraints and their prefixes,
/// and also tie in the associated operand values.
/// If this returns an empty vector, and if the constraint string itself
/// isn't empty, there was an error parsing.
TargetLowering::AsmOperandInfoVector TargetLowering::ParseConstraints(
ImmutableCallSite CS) const {
/// ConstraintOperands - Information about all of the constraints.
AsmOperandInfoVector ConstraintOperands;
const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
unsigned maCount = 0; // Largest number of multiple alternative constraints.
// Do a prepass over the constraints, canonicalizing them, and building up the
// ConstraintOperands list.
InlineAsm::ConstraintInfoVector
ConstraintInfos = IA->ParseConstraints();
unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
unsigned ResNo = 0; // ResNo - The result number of the next output.
for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) {
ConstraintOperands.push_back(AsmOperandInfo(ConstraintInfos[i]));
AsmOperandInfo &OpInfo = ConstraintOperands.back();
// Update multiple alternative constraint count.
if (OpInfo.multipleAlternatives.size() > maCount)
maCount = OpInfo.multipleAlternatives.size();
OpInfo.ConstraintVT = MVT::Other;
// Compute the value type for each operand.
switch (OpInfo.Type) {
case InlineAsm::isOutput:
// Indirect outputs just consume an argument.
if (OpInfo.isIndirect) {
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
break;
}
// The return value of the call is this value. As such, there is no
// corresponding argument.
assert(!CS.getType()->isVoidTy() &&
"Bad inline asm!");
if (const StructType *STy = dyn_cast<StructType>(CS.getType())) {
OpInfo.ConstraintVT = getValueType(STy->getElementType(ResNo));
} else {
assert(ResNo == 0 && "Asm only has one result!");
OpInfo.ConstraintVT = getValueType(CS.getType());
}
++ResNo;
break;
case InlineAsm::isInput:
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
break;
case InlineAsm::isClobber:
// Nothing to do.
break;
}
if (OpInfo.CallOperandVal) {
const llvm::Type *OpTy = OpInfo.CallOperandVal->getType();
if (OpInfo.isIndirect) {
const llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy);
if (!PtrTy)
report_fatal_error("Indirect operand for inline asm not a pointer!");
OpTy = PtrTy->getElementType();
}
// If OpTy is not a single value, it may be a struct/union that we
// can tile with integers.
if (!OpTy->isSingleValueType() && OpTy->isSized()) {
unsigned BitSize = TD->getTypeSizeInBits(OpTy);
switch (BitSize) {
default: break;
case 1:
case 8:
case 16:
case 32:
case 64:
case 128:
OpInfo.ConstraintVT =
EVT::getEVT(IntegerType::get(OpTy->getContext(), BitSize), true);
break;
}
} else if (dyn_cast<PointerType>(OpTy)) {
OpInfo.ConstraintVT = MVT::getIntegerVT(8*TD->getPointerSize());
} else {
OpInfo.ConstraintVT = EVT::getEVT(OpTy, true);
}
}
}
// If we have multiple alternative constraints, select the best alternative.
if (ConstraintInfos.size()) {
if (maCount) {
unsigned bestMAIndex = 0;
int bestWeight = -1;
// weight: -1 = invalid match, and 0 = so-so match to 5 = good match.
int weight = -1;
unsigned maIndex;
// Compute the sums of the weights for each alternative, keeping track
// of the best (highest weight) one so far.
for (maIndex = 0; maIndex < maCount; ++maIndex) {
int weightSum = 0;
for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
cIndex != eIndex; ++cIndex) {
AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
if (OpInfo.Type == InlineAsm::isClobber)
continue;
// If this is an output operand with a matching input operand,
// look up the matching input. If their types mismatch, e.g. one
// is an integer, the other is floating point, or their sizes are
// different, flag it as an maCantMatch.
if (OpInfo.hasMatchingInput()) {
AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
if (OpInfo.ConstraintVT != Input.ConstraintVT) {
if ((OpInfo.ConstraintVT.isInteger() !=
Input.ConstraintVT.isInteger()) ||
(OpInfo.ConstraintVT.getSizeInBits() !=
Input.ConstraintVT.getSizeInBits())) {
weightSum = -1; // Can't match.
break;
}
}
}
weight = getMultipleConstraintMatchWeight(OpInfo, maIndex);
if (weight == -1) {
weightSum = -1;
break;
}
weightSum += weight;
}
// Update best.
if (weightSum > bestWeight) {
bestWeight = weightSum;
bestMAIndex = maIndex;
}
}
// Now select chosen alternative in each constraint.
for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
cIndex != eIndex; ++cIndex) {
AsmOperandInfo& cInfo = ConstraintOperands[cIndex];
if (cInfo.Type == InlineAsm::isClobber)
continue;
cInfo.selectAlternative(bestMAIndex);
}
}
}
// Check and hook up tied operands, choose constraint code to use.
for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
cIndex != eIndex; ++cIndex) {
AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
// If this is an output operand with a matching input operand, look up the
// matching input. If their types mismatch, e.g. one is an integer, the
// other is floating point, or their sizes are different, flag it as an
// error.
if (OpInfo.hasMatchingInput()) {
AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
if (OpInfo.ConstraintVT != Input.ConstraintVT) {
if ((OpInfo.ConstraintVT.isInteger() !=
Input.ConstraintVT.isInteger()) ||
(OpInfo.ConstraintVT.getSizeInBits() !=
Input.ConstraintVT.getSizeInBits())) {
report_fatal_error("Unsupported asm: input constraint"
" with a matching output constraint of"
" incompatible type!");
}
}
}
}
return ConstraintOperands;
}
/// getConstraintGenerality - Return an integer indicating how general CT
/// is.
static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {
switch (CT) {
default: llvm_unreachable("Unknown constraint type!");
case TargetLowering::C_Other:
case TargetLowering::C_Unknown:
return 0;
case TargetLowering::C_Register:
return 1;
case TargetLowering::C_RegisterClass:
return 2;
case TargetLowering::C_Memory:
return 3;
}
}
/// Examine constraint type and operand type and determine a weight value.
/// This object must already have been set up with the operand type
/// and the current alternative constraint selected.
TargetLowering::ConstraintWeight
TargetLowering::getMultipleConstraintMatchWeight(
AsmOperandInfo &info, int maIndex) const {
InlineAsm::ConstraintCodeVector *rCodes;
if (maIndex >= (int)info.multipleAlternatives.size())
rCodes = &info.Codes;
else
rCodes = &info.multipleAlternatives[maIndex].Codes;
ConstraintWeight BestWeight = CW_Invalid;
// Loop over the options, keeping track of the most general one.
for (unsigned i = 0, e = rCodes->size(); i != e; ++i) {
ConstraintWeight weight =
getSingleConstraintMatchWeight(info, (*rCodes)[i].c_str());
if (weight > BestWeight)
BestWeight = weight;
}
return BestWeight;
}
/// Examine constraint type and operand type and determine a weight value.
/// This object must already have been set up with the operand type
/// and the current alternative constraint selected.
TargetLowering::ConstraintWeight
TargetLowering::getSingleConstraintMatchWeight(
AsmOperandInfo &info, const char *constraint) const {
ConstraintWeight weight = CW_Invalid;
Value *CallOperandVal = info.CallOperandVal;
// If we don't have a value, we can't do a match,
// but allow it at the lowest weight.
if (CallOperandVal == NULL)
return CW_Default;
// Look at the constraint type.
switch (*constraint) {
case 'i': // immediate integer.
case 'n': // immediate integer with a known value.
if (isa<ConstantInt>(CallOperandVal))
weight = CW_Constant;
break;
case 's': // non-explicit intregal immediate.
if (isa<GlobalValue>(CallOperandVal))
weight = CW_Constant;
break;
case 'E': // immediate float if host format.
case 'F': // immediate float.
if (isa<ConstantFP>(CallOperandVal))
weight = CW_Constant;
break;
case '<': // memory operand with autodecrement.
case '>': // memory operand with autoincrement.
case 'm': // memory operand.
case 'o': // offsettable memory operand
case 'V': // non-offsettable memory operand
weight = CW_Memory;
break;
case 'r': // general register.
case 'g': // general register, memory operand or immediate integer.
// note: Clang converts "g" to "imr".
if (CallOperandVal->getType()->isIntegerTy())
weight = CW_Register;
break;
case 'X': // any operand.
default:
weight = CW_Default;
break;
}
return weight;
}
/// ChooseConstraint - If there are multiple different constraints that we
/// could pick for this operand (e.g. "imr") try to pick the 'best' one.
/// This is somewhat tricky: constraints fall into four classes:
/// Other -> immediates and magic values
/// Register -> one specific register
/// RegisterClass -> a group of regs
/// Memory -> memory
/// Ideally, we would pick the most specific constraint possible: if we have
/// something that fits into a register, we would pick it. The problem here
/// is that if we have something that could either be in a register or in
/// memory that use of the register could cause selection of *other*
/// operands to fail: they might only succeed if we pick memory. Because of
/// this the heuristic we use is:
///
/// 1) If there is an 'other' constraint, and if the operand is valid for
/// that constraint, use it. This makes us take advantage of 'i'
/// constraints when available.
/// 2) Otherwise, pick the most general constraint present. This prefers
/// 'm' over 'r', for example.
///
static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo,
const TargetLowering &TLI,
SDValue Op, SelectionDAG *DAG) {
assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options");
unsigned BestIdx = 0;
TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown;
int BestGenerality = -1;
// Loop over the options, keeping track of the most general one.
for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) {
TargetLowering::ConstraintType CType =
TLI.getConstraintType(OpInfo.Codes[i]);
// If this is an 'other' constraint, see if the operand is valid for it.
// For example, on X86 we might have an 'rI' constraint. If the operand
// is an integer in the range [0..31] we want to use I (saving a load
// of a register), otherwise we must use 'r'.
if (CType == TargetLowering::C_Other && Op.getNode()) {
assert(OpInfo.Codes[i].size() == 1 &&
"Unhandled multi-letter 'other' constraint");
std::vector<SDValue> ResultOps;
TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i][0],
ResultOps, *DAG);
if (!ResultOps.empty()) {
BestType = CType;
BestIdx = i;
break;
}
}
// Things with matching constraints can only be registers, per gcc
// documentation. This mainly affects "g" constraints.
if (CType == TargetLowering::C_Memory && OpInfo.hasMatchingInput())
continue;
// This constraint letter is more general than the previous one, use it.
int Generality = getConstraintGenerality(CType);
if (Generality > BestGenerality) {
BestType = CType;
BestIdx = i;
BestGenerality = Generality;
}
}
OpInfo.ConstraintCode = OpInfo.Codes[BestIdx];
OpInfo.ConstraintType = BestType;
}
/// ComputeConstraintToUse - Determines the constraint code and constraint
/// type to use for the specific AsmOperandInfo, setting
/// OpInfo.ConstraintCode and OpInfo.ConstraintType.
void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo,
SDValue Op,
SelectionDAG *DAG) const {
assert(!OpInfo.Codes.empty() && "Must have at least one constraint");
// Single-letter constraints ('r') are very common.
if (OpInfo.Codes.size() == 1) {
OpInfo.ConstraintCode = OpInfo.Codes[0];
OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
} else {
ChooseConstraint(OpInfo, *this, Op, DAG);
}
// 'X' matches anything.
if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) {
// Labels and constants are handled elsewhere ('X' is the only thing
// that matches labels). For Functions, the type here is the type of
// the result, which is not what we want to look at; leave them alone.
Value *v = OpInfo.CallOperandVal;
if (isa<BasicBlock>(v) || isa<ConstantInt>(v) || isa<Function>(v)) {
OpInfo.CallOperandVal = v;
return;
}
// Otherwise, try to resolve it to something we know about by looking at
// the actual operand type.
if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) {
OpInfo.ConstraintCode = Repl;
OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
}
}
}
//===----------------------------------------------------------------------===//
// Loop Strength Reduction hooks
//===----------------------------------------------------------------------===//
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
bool TargetLowering::isLegalAddressingMode(const AddrMode &AM,
const Type *Ty) const {
// The default implementation of this implements a conservative RISCy, r+r and
// r+i addr mode.
// Allows a sign-extended 16-bit immediate field.
if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
return false;
// No global is ever allowed as a base.
if (AM.BaseGV)
return false;
// Only support r+r,
switch (AM.Scale) {
case 0: // "r+i" or just "i", depending on HasBaseReg.
break;
case 1:
if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed.
return false;
// Otherwise we have r+r or r+i.
break;
case 2:
if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed.
return false;
// Allow 2*r as r+r.
break;
}
return true;
}
/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
/// return a DAG expression to select that will generate the same value by
/// multiplying by a magic number. See:
/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
std::vector<SDNode*>* Created) const {
EVT VT = N->getValueType(0);
DebugLoc dl= N->getDebugLoc();
// Check to see if we can do this.
// FIXME: We should be more aggressive here.
if (!isTypeLegal(VT))
return SDValue();
APInt d = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue();
APInt::ms magics = d.magic();
// Multiply the numerator (operand 0) by the magic value
// FIXME: We should support doing a MUL in a wider type
SDValue Q;
if (isOperationLegalOrCustom(ISD::MULHS, VT))
Q = DAG.getNode(ISD::MULHS, dl, VT, N->getOperand(0),
DAG.getConstant(magics.m, VT));
else if (isOperationLegalOrCustom(ISD::SMUL_LOHI, VT))
Q = SDValue(DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(VT, VT),
N->getOperand(0),
DAG.getConstant(magics.m, VT)).getNode(), 1);
else
return SDValue(); // No mulhs or equvialent
// If d > 0 and m < 0, add the numerator
if (d.isStrictlyPositive() && magics.m.isNegative()) {
Q = DAG.getNode(ISD::ADD, dl, VT, Q, N->getOperand(0));
if (Created)
Created->push_back(Q.getNode());
}
// If d < 0 and m > 0, subtract the numerator.
if (d.isNegative() && magics.m.isStrictlyPositive()) {
Q = DAG.getNode(ISD::SUB, dl, VT, Q, N->getOperand(0));
if (Created)
Created->push_back(Q.getNode());
}
// Shift right algebraic if shift value is nonzero
if (magics.s > 0) {
Q = DAG.getNode(ISD::SRA, dl, VT, Q,
DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType())));
if (Created)
Created->push_back(Q.getNode());
}
// Extract the sign bit and add it to the quotient
SDValue T =
DAG.getNode(ISD::SRL, dl, VT, Q, DAG.getConstant(VT.getSizeInBits()-1,
getShiftAmountTy(Q.getValueType())));
if (Created)
Created->push_back(T.getNode());
return DAG.getNode(ISD::ADD, dl, VT, Q, T);
}
/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
/// return a DAG expression to select that will generate the same value by
/// multiplying by a magic number. See:
/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
SDValue TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG,
std::vector<SDNode*>* Created) const {
EVT VT = N->getValueType(0);
DebugLoc dl = N->getDebugLoc();
// Check to see if we can do this.
// FIXME: We should be more aggressive here.
if (!isTypeLegal(VT))
return SDValue();
// FIXME: We should use a narrower constant when the upper
// bits are known to be zero.
const APInt &N1C = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue();
APInt::mu magics = N1C.magicu();
SDValue Q = N->getOperand(0);
// If the divisor is even, we can avoid using the expensive fixup by shifting
// the divided value upfront.
if (magics.a != 0 && !N1C[0]) {
unsigned Shift = N1C.countTrailingZeros();
Q = DAG.getNode(ISD::SRL, dl, VT, Q,
DAG.getConstant(Shift, getShiftAmountTy(Q.getValueType())));
if (Created)
Created->push_back(Q.getNode());
// Get magic number for the shifted divisor.
magics = N1C.lshr(Shift).magicu(Shift);
assert(magics.a == 0 && "Should use cheap fixup now");
}
// Multiply the numerator (operand 0) by the magic value
// FIXME: We should support doing a MUL in a wider type
if (isOperationLegalOrCustom(ISD::MULHU, VT))
Q = DAG.getNode(ISD::MULHU, dl, VT, Q, DAG.getConstant(magics.m, VT));
else if (isOperationLegalOrCustom(ISD::UMUL_LOHI, VT))
Q = SDValue(DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(VT, VT), Q,
DAG.getConstant(magics.m, VT)).getNode(), 1);
else
return SDValue(); // No mulhu or equvialent
if (Created)
Created->push_back(Q.getNode());
if (magics.a == 0) {
assert(magics.s < N1C.getBitWidth() &&
"We shouldn't generate an undefined shift!");
return DAG.getNode(ISD::SRL, dl, VT, Q,
DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType())));
} else {
SDValue NPQ = DAG.getNode(ISD::SUB, dl, VT, N->getOperand(0), Q);
if (Created)
Created->push_back(NPQ.getNode());
NPQ = DAG.getNode(ISD::SRL, dl, VT, NPQ,
DAG.getConstant(1, getShiftAmountTy(NPQ.getValueType())));
if (Created)
Created->push_back(NPQ.getNode());
NPQ = DAG.getNode(ISD::ADD, dl, VT, NPQ, Q);
if (Created)
Created->push_back(NPQ.getNode());
return DAG.getNode(ISD::SRL, dl, VT, NPQ,
DAG.getConstant(magics.s-1, getShiftAmountTy(NPQ.getValueType())));
}
}
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