[llvm] [AMDGPU] InstCombine: fold invalid calls to amdgcn intrinsics into poison values (PR #191904)

[Shilei Tian via llvm-commits]

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@@ -0,0 +1,58 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -S -passes='instcombine' -mtriple=amdgcn-amd-amdhsa < %s | FileCheck %s
+
+; When amdgpu-no-workitem-id-x is set, calling the intrinsic is UB and the
+; call should be folded to poison.
+define i32 @no_workitem_id_x() #0 {
+; CHECK-LABEL: define i32 @no_workitem_id_x(
+; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    ret i32 poison
+;
+entry:
+  %tmp = call i32 @llvm.amdgcn.workitem.id.x()
+  ret i32 %tmp
+}
+
+define i32 @no_workitem_id_y() #1 {
+; CHECK-LABEL: define i32 @no_workitem_id_y(
+; CHECK-SAME: ) #[[ATTR1:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    ret i32 poison
+;
+entry:
+  %tmp = call i32 @llvm.amdgcn.workitem.id.y()
+  ret i32 %tmp
+}
+
+define i32 @no_workitem_id_z() #2 {
+; CHECK-LABEL: define i32 @no_workitem_id_z(
+; CHECK-SAME: ) #[[ATTR2:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    ret i32 poison
+;
+entry:
+  %tmp = call i32 @llvm.amdgcn.workitem.id.z()
+  ret i32 %tmp
+}
+
+; Without the attribute the calls are kept.
+define i32 @workitem_id_x_no_attr() {
+; CHECK-LABEL: define i32 @workitem_id_x_no_attr() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP:%.*]] = call i32 @llvm.amdgcn.workitem.id.x()
+; CHECK-NEXT:    ret i32 [[TMP]]
+;
+entry:
+  %tmp = call i32 @llvm.amdgcn.workitem.id.x()
+  ret i32 %tmp
+}
+
+declare i32 @llvm.amdgcn.workitem.id.x() #3
+declare i32 @llvm.amdgcn.workitem.id.y() #3
+declare i32 @llvm.amdgcn.workitem.id.z() #3
+
+attributes #0 = { "amdgpu-no-workitem-id-x" }
+attributes #1 = { "amdgpu-no-workitem-id-y" }
+attributes #2 = { "amdgpu-no-workitem-id-z" }
+attributes #3 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
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shiltian wrote:

Basically all these attributes can go.

https://github.com/llvm/llvm-project/pull/191904