[llvm] r334803 - Revert r334802 "[X86] Prevent folding stack reloads with instructions that have an undefined register update."

Craig Topper via llvm-commits llvm-commits at lists.llvm.org
Thu Jun 14 23:15:26 PDT 2018


Author: ctopper
Date: Thu Jun 14 23:15:26 2018
New Revision: 334803

URL: http://llvm.org/viewvc/llvm-project?rev=334803&view=rev
Log:
Revert r334802 "[X86] Prevent folding stack reloads with instructions that have an undefined register update."

There's a typo causing the build to fail.

Modified:
    llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
    llvm/trunk/test/CodeGen/X86/break-false-dep.ll
    llvm/trunk/test/CodeGen/X86/stack-folding-fp-avx1.ll

Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.cpp?rev=334803&r1=334802&r2=334803&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp Thu Jun 14 23:15:26 2018
@@ -8916,15 +8916,12 @@ static bool shouldPreventUndefRegUpdateM
   if (MF.getFunction().optForSize() || !hasUndefRegUpdate(MI.getOpcode()) ||
       !MI.getOperand(1).isReg())
     return false;
-
-  // Check if the register is explicitly marked as undef.
-  if (MI.getOperand(1).isUndef())
-    return true;
-
-  // Another possibility is that it is defined by by an IMPLICIT_DEF pseudo.
+ 
   MachineRegisterInfo &RegInfo = MF.getRegInfo();
   MachineInstr *VRegDef = RegInfo.getUniqueVRegDef(MI.getOperand(1).getReg());
-  return VRegDef && VRegDef->isImplicitDef()
+  if (VRegDef == nullptr)
+    return false;
+  return VRegDef->isImplicitDef();
 }
 
 

Modified: llvm/trunk/test/CodeGen/X86/break-false-dep.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/break-false-dep.ll?rev=334803&r1=334802&r2=334803&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/break-false-dep.ll (original)
+++ llvm/trunk/test/CodeGen/X86/break-false-dep.ll Thu Jun 14 23:15:26 2018
@@ -217,6 +217,7 @@ top:
 
 ; Make sure we are making a smart choice regarding undef registers and
 ; hiding the false dependency behind a true dependency
+; TODO: We shouldn't be folding the load here.
 define double @truedeps(float %arg) {
 top:
   tail call void asm sideeffect "", "~{xmm6},~{dirflag},~{fpsr},~{flags}"()
@@ -227,8 +228,8 @@ top:
   %tmp1 = fpext float %arg to double
   ret double %tmp1
 ;AVX-LABEL:@truedeps
-;AVX-NOT: vxorps
-;AVX: vcvtss2sd [[XMM0:%xmm[0-9]+]], [[XMM0]], {{%xmm[0-9]+}}
+;AVX: vxorps  [[XMM6:%xmm6]], [[XMM6]], [[XMM6]]
+;AVX: vcvtss2sd {{.*}}, [[XMM6]], {{%xmm[0-9]+}}
 }
 
 ; Make sure we are making a smart choice regarding undef registers and

Modified: llvm/trunk/test/CodeGen/X86/stack-folding-fp-avx1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/stack-folding-fp-avx1.ll?rev=334803&r1=334802&r2=334803&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/stack-folding-fp-avx1.ll (original)
+++ llvm/trunk/test/CodeGen/X86/stack-folding-fp-avx1.ll Thu Jun 14 23:15:26 2018
@@ -573,7 +573,7 @@ define i64 @stack_fold_cvtsd2si64_int(<2
 }
 declare i64 @llvm.x86.sse2.cvtsd2si64(<2 x double>) nounwind readnone
 
-define double @stack_fold_cvtsi2sd(i32 %a0) optsize {
+define double @stack_fold_cvtsi2sd(i32 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi2sd
   ;CHECK:  vcvtsi2sdl {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 4-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -581,7 +581,7 @@ define double @stack_fold_cvtsi2sd(i32 %
   ret double %2
 }
 
-define <2 x double> @stack_fold_cvtsi2sd_int(i32 %a0) optsize {
+define <2 x double> @stack_fold_cvtsi2sd_int(i32 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi2sd_int
   ;CHECK:  vcvtsi2sdl {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 4-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -590,7 +590,7 @@ define <2 x double> @stack_fold_cvtsi2sd
 }
 declare <2 x double> @llvm.x86.sse2.cvtsi2sd(<2 x double>, i32) nounwind readnone
 
-define double @stack_fold_cvtsi642sd(i64 %a0) optsize {
+define double @stack_fold_cvtsi642sd(i64 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi642sd
   ;CHECK:  vcvtsi2sdq {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 8-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -598,7 +598,7 @@ define double @stack_fold_cvtsi642sd(i64
   ret double %2
 }
 
-define <2 x double> @stack_fold_cvtsi642sd_int(i64 %a0) optsize {
+define <2 x double> @stack_fold_cvtsi642sd_int(i64 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi642sd_int
   ;CHECK:  vcvtsi2sdq {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 8-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -607,7 +607,7 @@ define <2 x double> @stack_fold_cvtsi642
 }
 declare <2 x double> @llvm.x86.sse2.cvtsi642sd(<2 x double>, i64) nounwind readnone
 
-define float @stack_fold_cvtsi2ss(i32 %a0) optsize {
+define float @stack_fold_cvtsi2ss(i32 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi2ss
   ;CHECK:  vcvtsi2ssl {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 4-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -615,7 +615,7 @@ define float @stack_fold_cvtsi2ss(i32 %a
   ret float %2
 }
 
-define <4 x float> @stack_fold_cvtsi2ss_int(i32 %a0) optsize {
+define <4 x float> @stack_fold_cvtsi2ss_int(i32 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi2ss_int
   ;CHECK:  vcvtsi2ssl {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 4-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -624,7 +624,7 @@ define <4 x float> @stack_fold_cvtsi2ss_
 }
 declare <4 x float> @llvm.x86.sse.cvtsi2ss(<4 x float>, i32) nounwind readnone
 
-define float @stack_fold_cvtsi642ss(i64 %a0) optsize {
+define float @stack_fold_cvtsi642ss(i64 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi642ss
   ;CHECK:  vcvtsi2ssq {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 8-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -632,7 +632,7 @@ define float @stack_fold_cvtsi642ss(i64
   ret float %2
 }
 
-define <4 x float> @stack_fold_cvtsi642ss_int(i64 %a0) optsize {
+define <4 x float> @stack_fold_cvtsi642ss_int(i64 %a0) {
   ;CHECK-LABEL: stack_fold_cvtsi642ss_int
   ;CHECK:  vcvtsi2ssq {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 8-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{rax},~{rbx},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"()
@@ -1653,7 +1653,7 @@ define <8 x float> @stack_fold_sqrtps_ym
 }
 declare <8 x float> @llvm.x86.avx.sqrt.ps.256(<8 x float>) nounwind readnone
 
-define double @stack_fold_sqrtsd(double %a0) optsize {
+define double @stack_fold_sqrtsd(double %a0) {
   ;CHECK-LABEL: stack_fold_sqrtsd
   ;CHECK:       vsqrtsd {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 8-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{xmm1},~{xmm2},~{xmm3},~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{xmm8},~{xmm9},~{xmm10},~{xmm11},~{xmm12},~{xmm13},~{xmm14},~{xmm15},~{flags}"()
@@ -1664,7 +1664,7 @@ declare double @llvm.sqrt.f64(double) no
 
 ; TODO stack_fold_sqrtsd_int
 
-define float @stack_fold_sqrtss(float %a0) optsize {
+define float @stack_fold_sqrtss(float %a0) {
   ;CHECK-LABEL: stack_fold_sqrtss
   ;CHECK:       vsqrtss {{-?[0-9]*}}(%rsp), {{%xmm[0-9][0-9]*}}, {{%xmm[0-9][0-9]*}} {{.*#+}} 4-byte Folded Reload
   %1 = tail call <2 x i64> asm sideeffect "nop", "=x,~{xmm1},~{xmm2},~{xmm3},~{xmm4},~{xmm5},~{xmm6},~{xmm7},~{xmm8},~{xmm9},~{xmm10},~{xmm11},~{xmm12},~{xmm13},~{xmm14},~{xmm15},~{flags}"()




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