[X86] Added BitScanForward/BitScanReverse memory folding + tests

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239257 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Simon Pilgrim 2015-06-07 18:34:25 +00:00
parent 7dcbed058f
commit 4c4f0921dc
2 changed files with 57 additions and 0 deletions

View File

@ -433,6 +433,12 @@ X86InstrInfo::X86InstrInfo(X86Subtarget &STI)
}
static const X86MemoryFoldTableEntry MemoryFoldTable1[] = {
{ X86::BSF16rr, X86::BSF16rm, 0 },
{ X86::BSF32rr, X86::BSF32rm, 0 },
{ X86::BSF64rr, X86::BSF64rm, 0 },
{ X86::BSR16rr, X86::BSR16rm, 0 },
{ X86::BSR32rr, X86::BSR32rm, 0 },
{ X86::BSR64rr, X86::BSR64rm, 0 },
{ X86::CMP16rr, X86::CMP16rm, 0 },
{ X86::CMP32rr, X86::CMP32rm, 0 },
{ X86::CMP64rr, X86::CMP64rm, 0 },

View File

@ -0,0 +1,51 @@
; RUN: llc -O3 -disable-peephole -mtriple=x86_64-unknown-unknown -mcpu=x86-64 < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-unknown"
; Stack reload folding tests.
;
; By including a nop call with sideeffects we can force a partial register spill of the
; relevant registers and check that the reload is correctly folded into the instruction.
;TODO stack_fold_bsf_i16
declare i16 @llvm.cttz.i16(i16, i1)
define i32 @stack_fold_bsf_i32(i32 %a0) {
;CHECK-LABEL: stack_fold_bsf_i32
;CHECK: bsfl {{-?[0-9]*}}(%rsp), %eax {{.*#+}} 4-byte Folded Reload
%1 = tail call i64 asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
%2 = call i32 @llvm.cttz.i32(i32 %a0, i1 -1)
ret i32 %2
}
declare i32 @llvm.cttz.i32(i32, i1)
define i64 @stack_fold_bsf_i64(i64 %a0) {
;CHECK-LABEL: stack_fold_bsf_i64
;CHECK: bsfq {{-?[0-9]*}}(%rsp), %rax {{.*#+}} 8-byte Folded Reload
%1 = tail call i64 asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
%2 = call i64 @llvm.cttz.i64(i64 %a0, i1 -1)
ret i64 %2
}
declare i64 @llvm.cttz.i64(i64, i1)
;TODO stack_fold_bsr_i16
declare i16 @llvm.ctlz.i16(i16, i1)
define i32 @stack_fold_bsr_i32(i32 %a0) {
;CHECK-LABEL: stack_fold_bsr_i32
;CHECK: bsrl {{-?[0-9]*}}(%rsp), %eax {{.*#+}} 4-byte Folded Reload
%1 = tail call i64 asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
%2 = call i32 @llvm.ctlz.i32(i32 %a0, i1 -1)
ret i32 %2
}
declare i32 @llvm.ctlz.i32(i32, i1)
define i64 @stack_fold_bsr_i64(i64 %a0) {
;CHECK-LABEL: stack_fold_bsr_i64
;CHECK: bsrq {{-?[0-9]*}}(%rsp), %rax {{.*#+}} 8-byte Folded Reload
%1 = tail call i64 asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
%2 = call i64 @llvm.ctlz.i64(i64 %a0, i1 -1)
ret i64 %2
}
declare i64 @llvm.ctlz.i64(i64, i1)