[llvm] r339197 - [NFC] adding tests for Y - (X + Y) --> -X

[Michael Berg via llvm-commits]

Author: mcberg2017
Date: Tue Aug  7 15:52:57 2018
New Revision: 339197

URL: http://llvm.org/viewvc/llvm-project?rev=339197&view=rev
Log:
[NFC] adding tests for Y - (X + Y) --> -X

Modified:
    llvm/trunk/test/CodeGen/X86/fp-fold.ll
    llvm/trunk/test/Transforms/InstCombine/fsub.ll

Modified: llvm/trunk/test/CodeGen/X86/fp-fold.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fp-fold.ll?rev=339197&r1=339196&r2=339197&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fp-fold.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fp-fold.ll Tue Aug  7 15:52:57 2018
@@ -88,6 +88,19 @@ define float @fsub_neg_x_y(float %x, flo
   ret float %r
 }
 
+define float @fsub_neg_y(float %x, float %y) {
+; UNSAFE-LABEL: fsub_neg_y:
+; UNSAFE:       # %bb.0:
+; UNSAFE-NEXT:    mulss {{.*}}(%rip), %xmm0
+; UNSAFE-NEXT:    subss %xmm1, %xmm0
+; UNSAFE-NEXT:    addss %xmm1, %xmm0
+; UNSAFE-NEXT:    retq
+  %mul = fmul float %x, 5.000000e+00
+  %add = fadd float %mul, %y 
+  %r = fsub nsz reassoc float %y, %add 
+  ret float %r
+}
+
 define float @fsub_negzero(float %x) {
 ; STRICT-LABEL: fsub_negzero:
 ; STRICT:       # %bb.0:

Modified: llvm/trunk/test/Transforms/InstCombine/fsub.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fsub.ll?rev=339197&r1=339196&r2=339197&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fsub.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/fsub.ll Tue Aug  7 15:52:57 2018
@@ -60,6 +60,19 @@ define float @sub_sub_nsz(float %x, floa
   ret float %t2
 }
 
+; With nsz and reassoc: Y - (X + Y) --> -X 
+define float @sub_add_neg_x(float %x, float %y) {
+; CHECK-LABEL: @sub_add_neg_x(
+; CHECK-NEXT:    [[TMP1:%.*]] = fmul float [[X:%.*]], 5.000000e+00
+; CHECK-NEXT:    [[T2:%.*]] = fsub reassoc nsz float -0.000000e+00, [[TMP1]]
+; CHECK-NEXT:    ret float [[T2]]
+;
+  %mul = fmul float %x, 5.000000e+00
+  %add = fadd float %mul, %y 
+  %r = fsub nsz reassoc float %y, %add
+  ret float %r
+}
+
 ; Same as above: if 'Z' is not -0.0, swap fsub operands and convert to fadd.
 
 define float @sub_sub_known_not_negzero(float %x, float %y) {