Add convergent-removing bits to FunctionAttrs pass.
Summary:
Remove the convergent attribute on any functions which provably do not
contain or invoke any convergent functions.
After this change, we'll be able to modify clang to conservatively add
'convergent' to all functions when compiling CUDA.
Reviewers: jingyue, joker.eph
Subscribers: llvm-commits, tra, jhen, hfinkel, resistor, chandlerc, arsenm
Differential Revision: http://reviews.llvm.org/D17013
llvm-svn: 260319
diff --git a/llvm/test/Transforms/FunctionAttrs/convergent.ll b/llvm/test/Transforms/FunctionAttrs/convergent.ll
new file mode 100644
index 0000000..46370d7
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/convergent.ll
@@ -0,0 +1,94 @@
+; RUN: opt < %s -basicaa -functionattrs -rpo-functionattrs -S | FileCheck %s
+
+; CHECK: Function Attrs
+; CHECK-NOT: convergent
+; CHECK-NEXT: define i32 @nonleaf()
+define i32 @nonleaf() convergent {
+ %a = call i32 @leaf()
+ ret i32 %a
+}
+
+; CHECK: Function Attrs
+; CHECK-NOT: convergent
+; CHECK-NEXT: define i32 @leaf()
+define i32 @leaf() convergent {
+ ret i32 0
+}
+
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: declare i32 @k()
+declare i32 @k() convergent
+
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: define i32 @extern()
+define i32 @extern() convergent {
+ %a = call i32 @k()
+ ret i32 %a
+}
+
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: define i32 @call_extern()
+define i32 @call_extern() convergent {
+ %a = call i32 @extern()
+ ret i32 %a
+}
+
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: declare void @llvm.cuda.syncthreads()
+declare void @llvm.cuda.syncthreads() convergent
+
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: define i32 @intrinsic()
+define i32 @intrinsic() convergent {
+ call void @llvm.cuda.syncthreads()
+ ret i32 0
+}
+
+@xyz = global i32 ()* null
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: define i32 @functionptr()
+define i32 @functionptr() convergent {
+ %1 = load i32 ()*, i32 ()** @xyz
+ %2 = call i32 %1()
+ ret i32 %2
+}
+
+; CHECK: Function Attrs
+; CHECK-NOT: convergent
+; CHECK-NEXT: define i32 @recursive1()
+define i32 @recursive1() convergent {
+ %a = call i32 @recursive2()
+ ret i32 %a
+}
+
+; CHECK: Function Attrs
+; CHECK-NOT: convergent
+; CHECK-NEXT: define i32 @recursive2()
+define i32 @recursive2() convergent {
+ %a = call i32 @recursive1()
+ ret i32 %a
+}
+
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: define i32 @noopt()
+define i32 @noopt() convergent optnone noinline {
+ %a = call i32 @noopt_friend()
+ ret i32 0
+}
+
+; A function which is mutually-recursive with a convergent, optnone function
+; shouldn't have its convergent attribute stripped.
+; CHECK: Function Attrs
+; CHECK-SAME: convergent
+; CHECK-NEXT: define i32 @noopt_friend()
+define i32 @noopt_friend() convergent {
+ %a = call i32 @noopt()
+ ret i32 0
+}