When gvn decides to replace an instruction with another, we have to patch the

replacement to make it at least as generic as the instruction being replaced.
This includes:
* dropping nsw/nuw flags
* getting the least restrictive tbaa and fpmath metadata
* merging ranges

Fixes PR12979.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157958 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 45 insertions, 0 deletions

diff --git a/test/Transforms/GVN/fpmath.ll b/test/Transforms/GVN/fpmath.ll
new file mode 100644
index 0000000..8ab2854
--- /dev/null
+++ b/test/Transforms/GVN/fpmath.ll
@@ -0,0 +1,45 @@
+; RUN: opt %s -gvn -S -o - | FileCheck %s
+
+define double @test1(double %x, double %y) {
+; CHECK: @test1(double %x, double %y)
+; CHECK: %add1 = fadd double %x, %y
+; CHECK-NOT: fpmath
+; CHECK: %foo = fadd double %add1, %add1
+  %add1 = fadd double %x, %y, !fpmath !0
+  %add2 = fadd double %x, %y
+  %foo = fadd double %add1, %add2
+  ret double %foo
+}
+
+define double @test2(double %x, double %y) {
+; CHECK: @test2(double %x, double %y)
+; CHECK: %add1 = fadd double %x, %y, !fpmath !0
+; CHECK: %foo = fadd double %add1, %add1
+  %add1 = fadd double %x, %y, !fpmath !0
+  %add2 = fadd double %x, %y, !fpmath !0
+  %foo = fadd double %add1, %add2
+  ret double %foo
+}
+
+define double @test3(double %x, double %y) {
+; CHECK: @test3(double %x, double %y)
+; CHECK: %add1 = fadd double %x, %y, !fpmath !1
+; CHECK: %foo = fadd double %add1, %add1
+  %add1 = fadd double %x, %y, !fpmath !1
+  %add2 = fadd double %x, %y, !fpmath !0
+  %foo = fadd double %add1, %add2
+  ret double %foo
+}
+
+define double @test4(double %x, double %y) {
+; CHECK: @test4(double %x, double %y)
+; CHECK: %add1 = fadd double %x, %y, !fpmath !1
+; CHECK: %foo = fadd double %add1, %add1
+  %add1 = fadd double %x, %y, !fpmath !0
+  %add2 = fadd double %x, %y, !fpmath !1
+  %foo = fadd double %add1, %add2
+  ret double %foo
+}
+
+!0 = metadata !{ float 5.0 }
+!1 = metadata !{ float 2.5 }