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

Add more comments and use early returns to reduce nesting in isLoadFoldable.
Also disable folding for V_SET0 to avoid introducing a const pool entry and
a const pool load.

rdar://10554090 and rdar://11873276


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161207 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 42 insertions, 22 deletions

diff --git a/test/CodeGen/X86/sse-minmax.ll b/test/CodeGen/X86/sse-minmax.ll
index 5d3dbce1df..3839e87561 100644
--- a/test/CodeGen/X86/sse-minmax.ll
+++ b/test/CodeGen/X86/sse-minmax.ll
@@ -137,13 +137,16 @@ define double @ole_inverse(double %x, double %y) nounwind {
 }
 
 ; CHECK:      ogt_x:
-; CHECK-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
+; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; CHECK-NEXT: maxsd %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      ogt_x:
-; UNSAFE-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; UNSAFE-NEXT: maxsd %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ogt_x:
-; FINITE-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; FINITE-NEXT: maxsd %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @ogt_x(double %x) nounwind {
   %c = fcmp ogt double %x, 0.000000e+00
@@ -152,13 +155,16 @@ define double @ogt_x(double %x) nounwind {
 }
 
 ; CHECK:      olt_x:
-; CHECK-NEXT: minsd LCP{{.*}}(%rip), %xmm0
+; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; CHECK-NEXT: minsd %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      olt_x:
-; UNSAFE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; UNSAFE-NEXT: minsd %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      olt_x:
-; FINITE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; FINITE-NEXT: minsd %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @olt_x(double %x) nounwind {
   %c = fcmp olt double %x, 0.000000e+00
@@ -211,10 +217,12 @@ define double @olt_inverse_x(double %x) nounwind {
 ; CHECK:      oge_x:
 ; CHECK:      ucomisd %xmm1, %xmm0
 ; UNSAFE:      oge_x:
-; UNSAFE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
+; UNSAFE-NEXT: maxsd   %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      oge_x:
-; FINITE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
+; FINITE-NEXT: maxsd   %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @oge_x(double %x) nounwind {
   %c = fcmp oge double %x, 0.000000e+00
@@ -225,10 +233,12 @@ define double @oge_x(double %x) nounwind {
 ; CHECK:      ole_x:
 ; CHECK:      ucomisd %xmm0, %xmm1
 ; UNSAFE:      ole_x:
-; UNSAFE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; UNSAFE-NEXT: minsd %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ole_x:
-; FINITE-NEXT: minsd LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; FINITE-NEXT: minsd %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @ole_x(double %x) nounwind {
   %c = fcmp ole double %x, 0.000000e+00
@@ -401,10 +411,12 @@ define double @ule_inverse(double %x, double %y) nounwind {
 ; CHECK:      ugt_x:
 ; CHECK:      ucomisd %xmm0, %xmm1
 ; UNSAFE:      ugt_x:
-; UNSAFE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
+; UNSAFE-NEXT: maxsd   %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ugt_x:
-; FINITE-NEXT: maxsd   LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
+; FINITE-NEXT: maxsd   %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @ugt_x(double %x) nounwind {
   %c = fcmp ugt double %x, 0.000000e+00
@@ -415,10 +427,12 @@ define double @ugt_x(double %x) nounwind {
 ; CHECK:      ult_x:
 ; CHECK:      ucomisd %xmm1, %xmm0
 ; UNSAFE:      ult_x:
-; UNSAFE-NEXT: minsd   LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
+; UNSAFE-NEXT: minsd   %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ult_x:
-; FINITE-NEXT: minsd   LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}}   %xmm1, %xmm1
+; FINITE-NEXT: minsd   %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @ult_x(double %x) nounwind {
   %c = fcmp ult double %x, 0.000000e+00
@@ -468,10 +482,12 @@ define double @ult_inverse_x(double %x) nounwind {
 ; CHECK-NEXT: movap{{[sd]}} %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      uge_x:
-; UNSAFE-NEXT: maxsd  LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
+; UNSAFE-NEXT: maxsd  %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      uge_x:
-; FINITE-NEXT: maxsd  LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
+; FINITE-NEXT: maxsd  %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @uge_x(double %x) nounwind {
   %c = fcmp uge double %x, 0.000000e+00
@@ -485,10 +501,12 @@ define double @uge_x(double %x) nounwind {
 ; CHECK-NEXT: movap{{[sd]}} %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      ule_x:
-; UNSAFE-NEXT: minsd  LCP{{.*}}(%rip), %xmm0
+; UNSAFE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
+; UNSAFE-NEXT: minsd  %xmm1, %xmm0
 ; UNSAFE-NEXT: ret
 ; FINITE:      ule_x:
-; FINITE-NEXT: minsd  LCP{{.*}}(%rip), %xmm0
+; FINITE-NEXT: xorp{{[sd]}}  %xmm1, %xmm1
+; FINITE-NEXT: minsd  %xmm1, %xmm0
 ; FINITE-NEXT: ret
 define double @ule_x(double %x) nounwind {
   %c = fcmp ule double %x, 0.000000e+00
@@ -497,7 +515,8 @@ define double @ule_x(double %x) nounwind {
 }
 
 ; CHECK:      uge_inverse_x:
-; CHECK-NEXT: minsd LCP{{.*}}(%rip), %xmm0
+; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; CHECK-NEXT: minsd %xmm1, %xmm0
 ; CHECK-NEXT: ret
 ; UNSAFE:      uge_inverse_x:
 ; UNSAFE-NEXT: xorp{{[sd]}} %xmm1, %xmm1
@@ -516,7 +535,8 @@ define double @uge_inverse_x(double %x) nounwind {
 }
 
 ; CHECK:      ule_inverse_x:
-; CHECK-NEXT: maxsd LCP{{.*}}(%rip), %xmm0
+; CHECK-NEXT: xorp{{[sd]}} %xmm1, %xmm1
+; CHECK-NEXT: maxsd %xmm1, %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 1e04f19ee8..367dd27f30 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: pxor LCP
-; CHECK: movdqa
+; CHECK: pcmp
+; CHECK: pxor
 ; CHECK: ret
 	%C = icmp sge <4 x i32> %A, %B
         %D = sext <4 x i1> %C to <4 x i32>