Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.

Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 36 insertions, 0 deletions

diff --git a/test/Transforms/JumpThreading/basic.ll b/test/Transforms/JumpThreading/basic.ll
index 46271379bd..f889c02c6f 100644
--- a/test/Transforms/JumpThreading/basic.ll
+++ b/test/Transforms/JumpThreading/basic.ll
@@ -476,3 +476,39 @@ exit1:
 ; CHECK: }
 }
 
+; In this test we check that block duplication is inhibited by the presence
+; of a function with the 'noduplicate' attribute.
+
+declare void @g()
+declare void @j()
+declare void @k()
+
+; CHECK: define void @h(i32 %p) {
+define void @h(i32 %p) {
+  %x = icmp ult i32 %p, 5
+  br i1 %x, label %l1, label %l2
+
+l1:
+  call void @j()
+  br label %l3
+
+l2:
+  call void @k()
+  br label %l3
+
+l3:
+; CHECK: call void @g() noduplicate
+; CHECK-NOT: call void @g() noduplicate
+  call void @g() noduplicate
+  %y = icmp ult i32 %p, 5
+  br i1 %y, label %l4, label %l5
+
+l4:
+  call void @j()
+  ret void
+
+l5:
+  call void @k()
+  ret void
+; CHECK: }
+}