Fast-math test for SimplifyInstruction: fold multiply by 0

llvm-svn: 168649

llvm/0007-Fast-math-test-for-SimplifyInstruction-fold-multiply.patch

+From a3d62a84e2805fc54fe721610de350cf23469aa4 Mon Sep 17 00:00:00 2001
+From: Michael Ilseman <milseman@apple.com>
+Date: Thu, 15 Nov 2012 10:04:58 -0800
+Subject: [PATCH 7/8] Fast-math test for SimplifyInstruction: fold multiply by
+ 0
+
+---
+ test/Transforms/InstSimplify/fast-math.ll | 35 +++++++++++++++++++++++++++++++
+ 1 file changed, 35 insertions(+)
+ create mode 100644 test/Transforms/InstSimplify/fast-math.ll
+
+diff --git a/test/Transforms/InstSimplify/fast-math.ll b/test/Transforms/InstSimplify/fast-math.ll
+new file mode 100644
+index 0000000..e4b3ea3
+--- /dev/null
++++ b/test/Transforms/InstSimplify/fast-math.ll
+@@ -0,0 +1,35 @@
++; RUN: opt < %s -instsimplify -S | FileCheck %s
++
++;; x * 0 ==> 0 when no-nans and no-signed-zero
++; CHECK: mul_zero_1
++define float @mul_zero_1(float %a) {
++  %b = fmul nsz nnan float %a, 0.0
++; CHECK: ret float 0.0
++  ret float %b
++}
++; CHECK: mul_zero_2
++define float @mul_zero_2(float %a) {
++  %b = fmul fast float 0.0, %a
++; CHECK: ret float 0.0
++  ret float %b
++}
++
++;; x * 0 =/=> 0 when there could be nans or -0
++; CHECK: no_mul_zero_1
++define float @no_mul_zero_1(float %a) {
++  %b = fmul nsz float %a, 0.0
++; CHECK: ret float %b
++  ret float %b
++}
++; CHECK: no_mul_zero_2
++define float @no_mul_zero_2(float %a) {
++  %b = fmul nnan float %a, 0.0
++; CHECK: ret float %b
++  ret float %b
++}
++; CHECK: no_mul_zero_3
++define float @no_mul_zero_3(float %a) {
++  %b = fmul float %a, 0.0
++; CHECK: ret float %b
++  ret float %b
++}
+-- 
+1.7.12.2 (Apple Git-36)
+