[Statepoint] Use default attributes for some GC intrinsics

This adds the default intrinsic attributes (nosync, nofree, nocallback,
willreturn) to the gc.result, gc.relocate, gc.pointer.base and
gc.pointer.offset intrinsics. As far as I understand, all of these
are supposed to be pure. Some quotes from LangRef:

> A gc.result is modeled as a ‘readnone’ pure function. It has no
> side effects since it is just a projection of the return value of
> the previous call represented by the gc.statepoint.

> A gc.relocate is modeled as a readnone pure function. It has no
> side effects since it is just a way to extract information about
> work done during the actual call modeled by the gc.statepoint.

Having willreturn in particular will be important to avoid
optimization regressions in the future.

Differential Revision: https://reviews.llvm.org/D136929

diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td
index 3050bd2..9667f58 100644 (file)
--- a/llvm/include/llvm/IR/Intrinsics.td
+++ b/llvm/include/llvm/IR/Intrinsics.td
@@ -1256,21 +1256,20 @@ def int_experimental_gc_statepoint : Intrinsic<[llvm_token_ty],
                                 ImmArg<ArgIndex<1>>, ImmArg<ArgIndex<3>>,
                                 ImmArg<ArgIndex<4>>]>;
 
-def int_experimental_gc_result   : Intrinsic<[llvm_any_ty], [llvm_token_ty],
-                                             [IntrNoMem]>;
-def int_experimental_gc_relocate : Intrinsic<[llvm_any_ty],
-                                             [llvm_token_ty, llvm_i32_ty,
-                                              llvm_i32_ty],
-                                             [IntrNoMem, ImmArg<ArgIndex<1>>,
-                                              ImmArg<ArgIndex<2>>]>;
-
-def int_experimental_gc_get_pointer_base : Intrinsic<[llvm_anyptr_ty],
-                 [llvm_anyptr_ty], [IntrNoMem, IntrWillReturn,
-                 ReadNone<ArgIndex<0>>, NoCapture<ArgIndex<0>>]>;
-
-def int_experimental_gc_get_pointer_offset : Intrinsic<[llvm_i64_ty],
-                 [llvm_anyptr_ty], [IntrNoMem, IntrWillReturn,
-                 ReadNone<ArgIndex<0>>, NoCapture<ArgIndex<0>>]>;
+def int_experimental_gc_result : DefaultAttrsIntrinsic<
+    [llvm_any_ty], [llvm_token_ty], [IntrNoMem]>;
+
+def int_experimental_gc_relocate : DefaultAttrsIntrinsic<
+    [llvm_any_ty], [llvm_token_ty, llvm_i32_ty, llvm_i32_ty],
+    [IntrNoMem, ImmArg<ArgIndex<1>>, ImmArg<ArgIndex<2>>]>;
+
+def int_experimental_gc_get_pointer_base : DefaultAttrsIntrinsic<
+    [llvm_anyptr_ty], [llvm_anyptr_ty],
+    [IntrNoMem, IntrWillReturn, ReadNone<ArgIndex<0>>, NoCapture<ArgIndex<0>>]>;
+
+def int_experimental_gc_get_pointer_offset : DefaultAttrsIntrinsic<
+    [llvm_i64_ty], [llvm_anyptr_ty],
+    [IntrNoMem, IntrWillReturn, ReadNone<ArgIndex<0>>, NoCapture<ArgIndex<0>>]>;
 
 //===------------------------ Coroutine Intrinsics ---------------===//
 // These are documented in docs/Coroutines.rst

diff --git a/llvm/test/Transforms/RewriteStatepointsForGC/statepoint-attrs.ll b/llvm/test/Transforms/RewriteStatepointsForGC/statepoint-attrs.ll
index 1eb6cef..120679b 100644 (file)
--- a/llvm/test/Transforms/RewriteStatepointsForGC/statepoint-attrs.ll
+++ b/llvm/test/Transforms/RewriteStatepointsForGC/statepoint-attrs.ll
@@ -20,6 +20,6 @@ define void @test1(i8 addrspace(1)* %arg) gc "statepoint-example" {
 
 attributes #1 = { norecurse noimplicitfloat }
 ;.
-; CHECK: attributes #[[ATTR0:[0-9]+]] = { nounwind memory(none) }
+; CHECK: attributes #[[ATTR0:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(none) }
 ; CHECK: attributes #[[ATTR1]] = { noimplicitfloat norecurse }
 ;.