eliminate additions of 0.0 when they are obviously dead. This has to be careful to

avoid turning -0.0 + 0.0 -> -0.0 which is incorrect.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46499 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/zero-point-zero-add.ll b/test/Transforms/InstCombine/zero-point-zero-add.ll
new file mode 100644
index 0000000..bae60d9
--- /dev/null
+++ b/test/Transforms/InstCombine/zero-point-zero-add.ll
@@ -0,0 +1,15 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep 0.0 | count 1
+
+declare double @abs(double)
+
+define double @test(double %X) {
+  %Y = add double %X, 0.0          ;; Should be a single add x, 0.0
+  %Z = add double %Y, 0.0
+  ret double %Z
+}
+
+define double @test1(double %X) {
+  %Y = call double @abs(double %X)
+  %Z = add double %Y, 0.0
+  ret double %Z
+}