llvm-6502/lib/Target/X86/AsmPrinter/X86InstComments.cpp
2010-08-29 03:08:08 +00:00

357 lines
12 KiB
C++

//===-- X86InstComments.cpp - Generate verbose-asm comments for instrs ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines functionality used to emit comments about X86 instructions to
// an output stream for -fverbose-asm.
//
//===----------------------------------------------------------------------===//
#include "X86InstComments.h"
#include "X86GenInstrNames.inc"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Vector Mask Decoding
//===----------------------------------------------------------------------===//
enum {
SM_SentinelZero = ~0U
};
static void DecodeINSERTPSMask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
// Defaults the copying the dest value.
ShuffleMask.push_back(0);
ShuffleMask.push_back(1);
ShuffleMask.push_back(2);
ShuffleMask.push_back(3);
// Decode the immediate.
unsigned ZMask = Imm & 15;
unsigned CountD = (Imm >> 4) & 3;
unsigned CountS = (Imm >> 6) & 3;
// CountS selects which input element to use.
unsigned InVal = 4+CountS;
// CountD specifies which element of destination to update.
ShuffleMask[CountD] = InVal;
// ZMask zaps values, potentially overriding the CountD elt.
if (ZMask & 1) ShuffleMask[0] = SM_SentinelZero;
if (ZMask & 2) ShuffleMask[1] = SM_SentinelZero;
if (ZMask & 4) ShuffleMask[2] = SM_SentinelZero;
if (ZMask & 8) ShuffleMask[3] = SM_SentinelZero;
}
static void DecodeMOVHLPSMask(SmallVectorImpl<unsigned> &ShuffleMask) {
ShuffleMask.push_back(3);
ShuffleMask.push_back(1);
}
static void DecodeMOVLHPSMask(SmallVectorImpl<unsigned> &ShuffleMask) {
ShuffleMask.push_back(0);
ShuffleMask.push_back(2);
}
static void DecodePSHUFMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
}
static void DecodePSHUFHWMask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
ShuffleMask.push_back(0);
ShuffleMask.push_back(1);
ShuffleMask.push_back(2);
ShuffleMask.push_back(3);
for (unsigned i = 0; i != 4; ++i) {
ShuffleMask.push_back(4+(Imm & 3));
Imm >>= 2;
}
}
static void DecodePSHUFLWMask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != 4; ++i) {
ShuffleMask.push_back((Imm & 3));
Imm >>= 2;
}
ShuffleMask.push_back(4);
ShuffleMask.push_back(5);
ShuffleMask.push_back(6);
ShuffleMask.push_back(7);
}
static void DecodePUNPCKLMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i);
ShuffleMask.push_back(i+NElts);
}
}
static void DecodePUNPCKHMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i+NElts/2);
ShuffleMask.push_back(i+NElts+NElts/2);
}
}
static void DecodeSHUFPSMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
// Part that reads from dest.
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
// Part that reads from src.
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(Imm % NElts + NElts);
Imm /= NElts;
}
}
static void DecodeUNPCKHPMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i+NElts/2); // Reads from dest
ShuffleMask.push_back(i+NElts+NElts/2); // Reads from src
}
}
/// DecodeUNPCKLPMask - This decodes the shuffle masks for unpcklps/unpcklpd
/// etc. NElts indicates the number of elements in the vector allowing it to
/// handle different datatypes and vector widths.
static void DecodeUNPCKLPMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i); // Reads from dest
ShuffleMask.push_back(i+NElts); // Reads from src
}
}
//===----------------------------------------------------------------------===//
// Top Level Entrypoint
//===----------------------------------------------------------------------===//
/// EmitAnyX86InstComments - This function decodes x86 instructions and prints
/// newline terminated strings to the specified string if desired. This
/// information is shown in disassembly dumps when verbose assembly is enabled.
void llvm::EmitAnyX86InstComments(const MCInst *MI, raw_ostream &OS,
const char *(*getRegName)(unsigned)) {
// If this is a shuffle operation, the switch should fill in this state.
SmallVector<unsigned, 8> ShuffleMask;
const char *DestName = 0, *Src1Name = 0, *Src2Name = 0;
switch (MI->getOpcode()) {
case X86::INSERTPSrr:
Src1Name = getRegName(MI->getOperand(1).getReg());
Src2Name = getRegName(MI->getOperand(2).getReg());
DecodeINSERTPSMask(MI->getOperand(3).getImm(), ShuffleMask);
break;
case X86::MOVLHPSrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodeMOVLHPSMask(ShuffleMask);
break;
case X86::MOVHLPSrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodeMOVHLPSMask(ShuffleMask);
break;
case X86::PSHUFDri:
Src1Name = getRegName(MI->getOperand(1).getReg());
// FALL THROUGH.
case X86::PSHUFDmi:
DestName = getRegName(MI->getOperand(0).getReg());
DecodePSHUFMask(4, MI->getOperand(MI->getNumOperands()-1).getImm(),
ShuffleMask);
break;
case X86::PSHUFHWri:
Src1Name = getRegName(MI->getOperand(1).getReg());
// FALL THROUGH.
case X86::PSHUFHWmi:
DestName = getRegName(MI->getOperand(0).getReg());
DecodePSHUFHWMask(MI->getOperand(MI->getNumOperands()-1).getImm(),
ShuffleMask);
break;
case X86::PSHUFLWri:
Src1Name = getRegName(MI->getOperand(1).getReg());
// FALL THROUGH.
case X86::PSHUFLWmi:
DestName = getRegName(MI->getOperand(0).getReg());
DecodePSHUFLWMask(MI->getOperand(MI->getNumOperands()-1).getImm(),
ShuffleMask);
break;
case X86::PUNPCKHBWrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKHBWrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKHMask(16, ShuffleMask);
break;
case X86::PUNPCKHWDrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKHWDrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKHMask(8, ShuffleMask);
break;
case X86::PUNPCKHDQrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKHDQrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKHMask(4, ShuffleMask);
break;
case X86::PUNPCKHQDQrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKHQDQrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKHMask(2, ShuffleMask);
break;
case X86::PUNPCKLBWrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKLBWrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKLMask(16, ShuffleMask);
break;
case X86::PUNPCKLWDrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKLWDrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKLMask(8, ShuffleMask);
break;
case X86::PUNPCKLDQrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKLDQrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKLMask(4, ShuffleMask);
break;
case X86::PUNPCKLQDQrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::PUNPCKLQDQrm:
Src1Name = getRegName(MI->getOperand(0).getReg());
DecodePUNPCKLMask(2, ShuffleMask);
break;
case X86::SHUFPDrri:
DecodeSHUFPSMask(2, MI->getOperand(3).getImm(), ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
Src2Name = getRegName(MI->getOperand(2).getReg());
break;
case X86::SHUFPSrri:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::SHUFPSrmi:
DecodeSHUFPSMask(4, MI->getOperand(3).getImm(), ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
break;
case X86::UNPCKLPDrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::UNPCKLPDrm:
DecodeUNPCKLPMask(2, ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
break;
case X86::UNPCKLPSrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::UNPCKLPSrm:
DecodeUNPCKLPMask(4, ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
break;
case X86::UNPCKHPDrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::UNPCKHPDrm:
DecodeUNPCKHPMask(2, ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
break;
case X86::UNPCKHPSrr:
Src2Name = getRegName(MI->getOperand(2).getReg());
// FALL THROUGH.
case X86::UNPCKHPSrm:
DecodeUNPCKHPMask(4, ShuffleMask);
Src1Name = getRegName(MI->getOperand(0).getReg());
break;
}
// If this was a shuffle operation, print the shuffle mask.
if (!ShuffleMask.empty()) {
if (DestName == 0) DestName = Src1Name;
OS << (DestName ? DestName : "mem") << " = ";
// If the two sources are the same, canonicalize the input elements to be
// from the first src so that we get larger element spans.
if (Src1Name == Src2Name) {
for (unsigned i = 0, e = ShuffleMask.size(); i != e; ++i) {
if ((int)ShuffleMask[i] >= 0 && // Not sentinel.
ShuffleMask[i] >= e) // From second mask.
ShuffleMask[i] -= e;
}
}
// The shuffle mask specifies which elements of the src1/src2 fill in the
// destination, with a few sentinel values. Loop through and print them
// out.
for (unsigned i = 0, e = ShuffleMask.size(); i != e; ++i) {
if (i != 0)
OS << ',';
if (ShuffleMask[i] == SM_SentinelZero) {
OS << "zero";
continue;
}
// Otherwise, it must come from src1 or src2. Print the span of elements
// that comes from this src.
bool isSrc1 = ShuffleMask[i] < ShuffleMask.size();
const char *SrcName = isSrc1 ? Src1Name : Src2Name;
OS << (SrcName ? SrcName : "mem") << '[';
bool IsFirst = true;
while (i != e &&
(int)ShuffleMask[i] >= 0 &&
(ShuffleMask[i] < ShuffleMask.size()) == isSrc1) {
if (!IsFirst)
OS << ',';
else
IsFirst = false;
OS << ShuffleMask[i] % ShuffleMask.size();
++i;
}
OS << ']';
--i; // For loop increments element #.
}
//MI->print(OS, 0);
OS << "\n";
}
}