X86 Peephole: fold loads to the source register operand if possible.

Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.

This patch is a rework of r160919 and was tested on clang self-host on my local
machine.

rdar://10554090 and rdar://11873276


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161152 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 61 insertions, 54 deletions

diff --git a/test/CodeGen/X86/2012-05-19-avx2-store.ll b/test/CodeGen/X86/2012-05-19-avx2-store.ll
index 61fef90..1c1e8e2 100644
--- a/test/CodeGen/X86/2012-05-19-avx2-store.ll
+++ b/test/CodeGen/X86/2012-05-19-avx2-store.ll
@@ -3,8 +3,7 @@
 define void @double_save(<4 x i32>* %Ap, <4 x i32>* %Bp, <8 x i32>* %P) nounwind ssp {
 entry:
   ; CHECK: vmovaps
-  ; CHECK: vmovaps
-  ; CHECK: vinsertf128
+  ; CHECK: vinsertf128 $1, ([[A0:%rdi|%rsi]]),
   ; CHECK: vmovups
   %A = load <4 x i32>* %Ap
   %B = load <4 x i32>* %Bp
diff --git a/test/CodeGen/X86/break-sse-dep.ll b/test/CodeGen/X86/break-sse-dep.ll
index 3e65867..4d80189 100644
--- a/test/CodeGen/X86/break-sse-dep.ll
+++ b/test/CodeGen/X86/break-sse-dep.ll
@@ -34,8 +34,7 @@ entry:
 define double @squirt(double* %x) nounwind {
 entry:
 ; CHECK: squirt:
-; CHECK: movsd ([[A0]]), %xmm0
-; CHECK: sqrtsd %xmm0, %xmm0
+; CHECK: sqrtsd ([[A0]]), %xmm0
   %z = load double* %x
   %t = call double @llvm.sqrt.f64(double %z)
   ret double %t
diff --git a/test/CodeGen/X86/fold-load.ll b/test/CodeGen/X86/fold-load.ll
index e03cb7e..c961f75 100644
--- a/test/CodeGen/X86/fold-load.ll
+++ b/test/CodeGen/X86/fold-load.ll
@@ -45,3 +45,29 @@ L:
 
 }
 
+; rdar://10554090
+; xor in exit block will be CSE'ed and load will be folded to xor in entry.
+define i1 @test3(i32* %P, i32* %Q) nounwind {
+; CHECK: test3:
+; CHECK: movl 8(%esp), %eax
+; CHECK: xorl (%eax),
+; CHECK: j
+; CHECK-NOT: xor
+entry:
+  %0 = load i32* %P, align 4
+  %1 = load i32* %Q, align 4
+  %2 = xor i32 %0, %1
+  %3 = and i32 %2, 65535
+  %4 = icmp eq i32 %3, 0
+  br i1 %4, label %exit, label %land.end
+
+exit:
+  %shr.i.i19 = xor i32 %1, %0
+  %5 = and i32 %shr.i.i19, 2147418112
+  %6 = icmp eq i32 %5, 0
+  br label %land.end
+
+land.end:
+  %7 = phi i1 [ %6, %exit ], [ false, %entry ]
+  ret i1 %7
+}
diff --git a/test/CodeGen/X86/fold-pcmpeqd-1.ll b/test/CodeGen/X86/fold-pcmpeqd-1.ll
index cc4198d..a35dccd 100644
--- a/test/CodeGen/X86/fold-pcmpeqd-1.ll
+++ b/test/CodeGen/X86/fold-pcmpeqd-1.ll
@@ -1,11 +1,14 @@
-; RUN: llc < %s -march=x86 -mattr=+sse2 > %t
-; RUN: grep pcmpeqd %t | count 1
-; RUN: grep xor %t | count 1
-; RUN: not grep LCP %t
+; RUN: llc < %s -march=x86 -mattr=+sse2 | FileCheck %s
 
 define <2 x double> @foo() nounwind {
   ret <2 x double> bitcast (<2 x i64><i64 -1, i64 -1> to <2 x double>)
+; CHECK: foo:
+; CHECK: pcmpeqd %xmm{{[0-9]+}}, %xmm{{[0-9]+}}
+; CHECK-NEXT: ret
 }
 define <2 x double> @bar() nounwind {
   ret <2 x double> bitcast (<2 x i64><i64 0, i64 0> to <2 x double>)
+; CHECK: bar:
+; CHECK: xorps %xmm{{[0-9]+}}, %xmm{{[0-9]+}}
+; CHECK-NEXT: ret
 }
diff --git a/test/CodeGen/X86/sse-minmax.ll b/test/CodeGen/X86/sse-minmax.ll
index 4405f68..5d3dbce 100644
--- a/test/CodeGen/X86/sse-minmax.ll
+++ b/test/CodeGen/X86/sse-minmax.ll
@@ -1,6 +1,6 @@
-; RUN: llc < %s -march=x86-64 -mcpu=nehalem -asm-verbose=false  | FileCheck %s
-; RUN: llc < %s -march=x86-64 -mcpu=nehalem -asm-verbose=false -enable-unsafe-fp-math -enable-no-nans-fp-math  | FileCheck -check-prefix=UNSAFE %s
-; RUN: llc < %s -march=x86-64 -mcpu=nehalem -asm-verbose=false -enable-no-nans-fp-math  | FileCheck -check-prefix=FINITE %s
+; RUN: llc < %s -march=x86-64 -mtriple=x86_64-apple-darwin -mcpu=nehalem -asm-verbose=false  | FileCheck %s
+; RUN: llc < %s -march=x86-64 -mtriple=x86_64-apple-darwin -mcpu=nehalem -asm-verbose=false -enable-unsafe-fp-math -enable-no-nans-fp-math  | FileCheck -check-prefix=UNSAFE %s
+; RUN: llc < %s -march=x86-64 -mtriple=x86_64-apple-darwin -mcpu=nehalem -asm-verbose=false -enable-no-nans-fp-math  | FileCheck -check-prefix=FINITE %s
 
 ; Some of these patterns can be matched as SSE min or max. Some of
 ; then can be matched provided that the operands are swapped.
@@ -137,16 +137,13 @@ define double @ole_inverse(double %x, double %y) nounwind {
 }
 
 ; CHECK:      ogt_x:
-; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; CHECK-NEXT: maxsd %xmm1, %xmm0
+; CHECK-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      ogt_x:
-; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; UNSAFE-NEXT: maxsd %xmm1, %xmm0
+; UNSAFE-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ogt_x:
-; FINITE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; FINITE-NEXT: maxsd %xmm1, %xmm0
+; FINITE-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @ogt_x(double %x) nounwind {
   %c = fcmp ogt double %x, 0.000000e+00
@@ -155,16 +152,13 @@ define double @ogt_x(double %x) nounwind {
 }
 
 ; CHECK:      olt_x:
-; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; CHECK-NEXT: minsd %xmm1, %xmm0
+; CHECK-NEXT: minsd LCP{{.*}}(%rip), %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      olt_x:
-; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; UNSAFE-NEXT: minsd %xmm1, %xmm0
+; UNSAFE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      olt_x:
-; FINITE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; FINITE-NEXT: minsd %xmm1, %xmm0
+; FINITE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @olt_x(double %x) nounwind {
   %c = fcmp olt double %x, 0.000000e+00
@@ -217,12 +211,10 @@ define double @olt_inverse_x(double %x) nounwind {
 ; CHECK:      oge_x:
 ; CHECK:      ucomisd %xmm1, %xmm0
 ; UNSAFE:      oge_x:
-; UNSAFE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
-; UNSAFE-NEXT: maxsd   %xmm1, %xmm0
+; UNSAFE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      oge_x:
-; FINITE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
-; FINITE-NEXT: maxsd   %xmm1, %xmm0
+; FINITE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @oge_x(double %x) nounwind {
   %c = fcmp oge double %x, 0.000000e+00
@@ -233,12 +225,10 @@ define double @oge_x(double %x) nounwind {
 ; CHECK:      ole_x:
 ; CHECK:      ucomisd %xmm0, %xmm1
 ; UNSAFE:      ole_x:
-; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; UNSAFE-NEXT: minsd %xmm1, %xmm0
+; UNSAFE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ole_x:
-; FINITE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; FINITE-NEXT: minsd %xmm1, %xmm0
+; FINITE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @ole_x(double %x) nounwind {
   %c = fcmp ole double %x, 0.000000e+00
@@ -411,12 +401,10 @@ define double @ule_inverse(double %x, double %y) nounwind {
 ; CHECK:      ugt_x:
 ; CHECK:      ucomisd %xmm0, %xmm1
 ; UNSAFE:      ugt_x:
-; UNSAFE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
-; UNSAFE-NEXT: maxsd   %xmm1, %xmm0
+; UNSAFE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ugt_x:
-; FINITE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
-; FINITE-NEXT: maxsd   %xmm1, %xmm0
+; FINITE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @ugt_x(double %x) nounwind {
   %c = fcmp ugt double %x, 0.000000e+00
@@ -427,12 +415,10 @@ define double @ugt_x(double %x) nounwind {
 ; CHECK:      ult_x:
 ; CHECK:      ucomisd %xmm1, %xmm0
 ; UNSAFE:      ult_x:
-; UNSAFE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
-; UNSAFE-NEXT: minsd   %xmm1, %xmm0
+; UNSAFE-NEXT: minsd   LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ult_x:
-; FINITE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
-; FINITE-NEXT: minsd   %xmm1, %xmm0
+; FINITE-NEXT: minsd   LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @ult_x(double %x) nounwind {
   %c = fcmp ult double %x, 0.000000e+00
@@ -482,12 +468,10 @@ define double @ult_inverse_x(double %x) nounwind {
 ; CHECK-NEXT: movap{{[sd]}} %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      uge_x:
-; UNSAFE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
-; UNSAFE-NEXT: maxsd  %xmm1, %xmm0
+; UNSAFE-NEXT: maxsd  LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      uge_x:
-; FINITE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
-; FINITE-NEXT: maxsd  %xmm1, %xmm0
+; FINITE-NEXT: maxsd  LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @uge_x(double %x) nounwind {
   %c = fcmp uge double %x, 0.000000e+00
@@ -501,12 +485,10 @@ define double @uge_x(double %x) nounwind {
 ; CHECK-NEXT: movap{{[sd]}} %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      ule_x:
-; UNSAFE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
-; UNSAFE-NEXT: minsd  %xmm1, %xmm0
+; UNSAFE-NEXT: minsd  LCP{{.*}}(%rip), %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ule_x:
-; FINITE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
-; FINITE-NEXT: minsd  %xmm1, %xmm0
+; FINITE-NEXT: minsd  LCP{{.*}}(%rip), %xmm0
 ; FINITE-NEXT: ret
 define double @ule_x(double %x) nounwind {
   %c = fcmp ule double %x, 0.000000e+00
@@ -515,8 +497,7 @@ define double @ule_x(double %x) nounwind {
 }
 
 ; CHECK:      uge_inverse_x:
-; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; CHECK-NEXT: minsd %xmm1, %xmm0
+; CHECK-NEXT: minsd LCP{{.*}}(%rip), %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      uge_inverse_x:
 ; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
@@ -535,8 +516,7 @@ define double @uge_inverse_x(double %x) nounwind {
 }
 
 ; CHECK:      ule_inverse_x:
-; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
-; CHECK-NEXT: maxsd %xmm1, %xmm0
+; CHECK-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      ule_inverse_x:
 ; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
diff --git a/test/CodeGen/X86/vec_compare.ll b/test/CodeGen/X86/vec_compare.ll
index 39c9b77..1e04f19 100644
--- a/test/CodeGen/X86/vec_compare.ll
+++ b/test/CodeGen/X86/vec_compare.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=x86 -mcpu=yonah | FileCheck %s
+; RUN: llc < %s -march=x86 -mcpu=yonah -mtriple=i386-apple-darwin | FileCheck %s
 
 
 define <4 x i32> @test1(<4 x i32> %A, <4 x i32> %B) nounwind {
@@ -14,8 +14,8 @@ define <4 x i32> @test1(<4 x i32> %A, <4 x i32> %B) nounwind {
 define <4 x i32> @test2(<4 x i32> %A, <4 x i32> %B) nounwind {
 ; CHECK: test2:
 ; CHECK: pcmp
-; CHECK: pcmp
-; CHECK: pxor
+; CHECK: pxor LCP
+; CHECK: movdqa
 ; CHECK: ret
 	%C = icmp sge <4 x i32> %A, %B
         %D = sext <4 x i1> %C to <4 x i32>