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.

rdar://10554090 and rdar://11873276


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160919 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 57 insertions, 50 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..ec82389 100644
--- a/test/CodeGen/X86/sse-minmax.ll
+++ b/test/CodeGen/X86/sse-minmax.ll
@@ -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..fffcf91 100644
--- a/test/CodeGen/X86/vec_compare.ll
+++ b/test/CodeGen/X86/vec_compare.ll
@@ -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>