Teach ISel not to optimize 'optnone' functions.

Based on work by Andrea Di Biagio.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195317 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 31 insertions, 0 deletions

diff --git a/test/CodeGen/Generic/isel-optnone.ll b/test/CodeGen/Generic/isel-optnone.ll
new file mode 100644
index 0000000000..405a1bc50a
--- /dev/null
+++ b/test/CodeGen/Generic/isel-optnone.ll
@@ -0,0 +1,31 @@
+; RUN: llc -debug < %s -o /dev/null 2>&1 | FileCheck %s
+
+; Verify that the backend correctly overrides the optimization level
+; of optnone functions during instruction selection.
+
+define float @foo(float %x) #0 {
+entry:
+  %add = fadd fast float %x, %x
+  %add1 = fadd fast float %add, %x
+  ret float %add1
+}
+
+; CHECK-NOT: Changing optimization level for Function foo
+; CHECK-NOT: Restoring optimization level for Function foo
+
+; Function Attrs: noinline optnone
+define float @fooWithOptnone(float %x) #1 {
+entry:
+  %add = fadd fast float %x, %x
+  %add1 = fadd fast float %add, %x
+  ret float %add1
+}
+
+; CHECK: Changing optimization level for Function fooWithOptnone
+; CHECK-NEXT: Before: -O2 ; After: -O0
+
+; CHECK: Restoring optimization level for Function fooWithOptnone
+; CHECK-NEXT: Before: -O0 ; After: -O2
+
+attributes #0 = { "unsafe-fp-math"="true" }
+attributes #1 = { noinline optnone "unsafe-fp-math"="true" }