[attrs] Split off the forced attributes utility into its own pass that

is (by default) run much earlier than FuncitonAttrs proper.

This allows forcing optnone or other widely impactful attributes. It is
also a bit simpler as the force attribute behavior needs no specific
iteration order.

I've added the pass into the default module pass pipeline and LTO pass
pipeline which mirrors where function attrs itself was being run.

Differential Revision: http://reviews.llvm.org/D15668

llvm-svn: 256465

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/test/Transforms/ForcedFunctionAttrs/forced.ll b/llvm/test/Transforms/ForcedFunctionAttrs/forced.ll
new file mode 100644
index 00000000000..a41e9c0efbe
--- /dev/null
+++ b/llvm/test/Transforms/ForcedFunctionAttrs/forced.ll
@@ -0,0 +1,12 @@
+; RUN: opt < %s -S -forceattrs | FileCheck %s --check-prefix=CHECK-CONTROL
+; RUN: opt < %s -S -forceattrs -force-attribute foo:noinline | FileCheck %s --check-prefix=CHECK-FOO
+; RUN: opt < %s -S -passes=forceattrs -force-attribute foo:noinline | FileCheck %s --check-prefix=CHECK-FOO
+
+; CHECK-CONTROL: define void @foo() {
+; CHECK-FOO: define void @foo() #0 {
+define void @foo() {
+  ret void
+}
+
+
+; CHECK-FOO: attributes #0 = { noinline }