AtomicExpand: Preserve metadata when expanding partword RMW (#89769)

This will be important for AMDGPU in a future patch.

Author: arsenm

llvm/lib/CodeGen/AtomicExpandPass.cpp

@@ -37,6 +37,7 @@
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/MemoryModelRelaxationAnnotations.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
@@ -937,6 +938,36 @@ void AtomicExpandImpl::expandPartwordAtomicRMW(
  AI->eraseFromParent();
 }
 
+/// Copy metadata that's safe to preserve when widening atomics.
+static void copyMetadataForAtomic(Instruction &Dest,
+ const Instruction &Source) {
+ SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
+ Source.getAllMetadata(MD);
+ LLVMContext &Ctx = Dest.getContext();
+ MDBuilder MDB(Ctx);
+
+ for (auto [ID, N] : MD) {
+ switch (ID) {
+ case LLVMContext::MD_dbg:
+ case LLVMContext::MD_tbaa:
+ case LLVMContext::MD_tbaa_struct:
+ case LLVMContext::MD_alias_scope:
+ case LLVMContext::MD_noalias:
+ case LLVMContext::MD_access_group:
+ case LLVMContext::MD_mmra:
+ Dest.setMetadata(ID, N);
+ break;
+ default:
+ if (ID == Ctx.getMDKindID("amdgpu.no.remote.memory"))
+ Dest.setMetadata(ID, N);
+ else if (ID == Ctx.getMDKindID("amdgpu.no.fine.grained.memory"))
+ Dest.setMetadata(ID, N);
+
+ break;
+ }
+ }
+}
+
 // Widen the bitwise atomicrmw (or/xor/and) to the minimum supported width.
 AtomicRMWInst *AtomicExpandImpl::widenPartwordAtomicRMW(AtomicRMWInst *AI) {
  ReplacementIRBuilder Builder(AI, *DL);
@@ -965,7 +996,8 @@ AtomicRMWInst *AtomicExpandImpl::widenPartwordAtomicRMW(AtomicRMWInst *AI) {
  AtomicRMWInst *NewAI = Builder.CreateAtomicRMW(
  Op, PMV.AlignedAddr, NewOperand, PMV.AlignedAddrAlignment,
  AI->getOrdering(), AI->getSyncScopeID());
- // TODO: Preserve metadata
+
+ copyMetadataForAtomic(*NewAI, *AI);
 
  Value *FinalOldResult = extractMaskedValue(Builder, NewAI, PMV);
  AI->replaceAllUsesWith(FinalOldResult);

llvm/test/Transforms/AtomicExpand/AMDGPU/expand-atomic-i16.ll

@@ -176,9 +176,9 @@ define i16 @test_atomicrmw_and_i16_global_agent_align4(ptr addrspace(1) %ptr, i1
  ret i16 %res
 }
 
-; Preserve unknown metadata
-define i16 @test_atomicrmw_and_i16_global_agent_preserve_md(ptr addrspace(1) %ptr, i16 %value) {
-; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_preserve_md(
+; Drop unknown metadata and noundef
+define i16 @test_atomicrmw_and_i16_global_agent_drop_md(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_drop_md(
 ; CHECK-NEXT: [[ALIGNEDADDR:%.*]] = call ptr addrspace(1) @llvm.ptrmask.p1.i64(ptr addrspace(1) [[PTR:%.*]], i64 -4)
 ; CHECK-NEXT: [[TMP1:%.*]] = ptrtoint ptr addrspace(1) [[PTR]] to i64
 ; CHECK-NEXT: [[PTRLSB:%.*]] = and i64 [[TMP1]], 3
@@ -198,9 +198,9 @@ define i16 @test_atomicrmw_and_i16_global_agent_preserve_md(ptr addrspace(1) %pt
  ret i16 %res
 }
 
-; Preserve unknown metadata
-define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_md(ptr addrspace(1) %ptr, i16 %value) {
-; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_preserve_md(
+; Drop unknown metadata
+define i16 @test_atomicrmw_and_i16_global_agent_align4_drop_md(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_drop_md(
 ; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
 ; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
 ; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4
@@ -211,6 +211,89 @@ define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_md(ptr addrspace
  ret i16 %res
 }
 
+; Drop noundef, preserve mmra
+define i16 @test_atomicrmw_and_i16_global_agent_preserve_mmra(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_preserve_mmra(
+; CHECK-NEXT: [[ALIGNEDADDR:%.*]] = call ptr addrspace(1) @llvm.ptrmask.p1.i64(ptr addrspace(1) [[PTR:%.*]], i64 -4)
+; CHECK-NEXT: [[TMP1:%.*]] = ptrtoint ptr addrspace(1) [[PTR]] to i64
+; CHECK-NEXT: [[PTRLSB:%.*]] = and i64 [[TMP1]], 3
+; CHECK-NEXT: [[TMP2:%.*]] = shl i64 [[PTRLSB]], 3
+; CHECK-NEXT: [[SHIFTAMT:%.*]] = trunc i64 [[TMP2]] to i32
+; CHECK-NEXT: [[MASK:%.*]] = shl i32 65535, [[SHIFTAMT]]
+; CHECK-NEXT: [[INV_MASK:%.*]] = xor i32 [[MASK]], -1
+; CHECK-NEXT: [[TMP3:%.*]] = zext i16 [[VALUE:%.*]] to i32
+; CHECK-NEXT: [[VALOPERAND_SHIFTED:%.*]] = shl i32 [[TMP3]], [[SHIFTAMT]]
+; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[VALOPERAND_SHIFTED]], [[INV_MASK]]
+; CHECK-NEXT: [[TMP4:%.*]] = atomicrmw and ptr addrspace(1) [[ALIGNEDADDR]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !mmra [[META0:![0-9]+]]
+; CHECK-NEXT: [[SHIFTED:%.*]] = lshr i32 [[TMP4]], [[SHIFTAMT]]
+; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[SHIFTED]] to i16
+; CHECK-NEXT: ret i16 [[EXTRACTED]]
+;
+ %res = atomicrmw and ptr addrspace(1) %ptr, i16 %value syncscope("agent") seq_cst, !noundef !0, !mmra !1
+ ret i16 %res
+}
+
+; Drop noundef, preserve mmra
+define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_mmra(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_preserve_mmra(
+; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
+; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !mmra [[META0]]
+; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
+; CHECK-NEXT: ret i16 [[EXTRACTED]]
+;
+ %res = atomicrmw and ptr addrspace(1) %ptr, i16 %value syncscope("agent") seq_cst, align 4, !noundef !0, !mmra !1
+ ret i16 %res
+}
+
+define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_alias_scope(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_preserve_alias_scope(
+; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
+; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !alias.scope [[META1:![0-9]+]]
+; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
+; CHECK-NEXT: ret i16 [[EXTRACTED]]
+;
+ %res = atomicrmw and ptr addrspace(1) %ptr, i16 %value syncscope("agent") seq_cst, align 4, !alias.scope !2
+ ret i16 %res
+}
+
+define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_noalias(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_preserve_noalias(
+; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
+; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !noalias [[META1]]
+; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
+; CHECK-NEXT: ret i16 [[EXTRACTED]]
+;
+ %res = atomicrmw and ptr addrspace(1) %ptr, i16 %value syncscope("agent") seq_cst, align 4, !noalias !2
+ ret i16 %res
+}
+
+define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_tbaa_struct(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_preserve_tbaa_struct(
+; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
+; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !tbaa.struct [[TBAA_STRUCT4:![0-9]+]]
+; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
+; CHECK-NEXT: ret i16 [[EXTRACTED]]
+;
+ %res = atomicrmw and ptr addrspace(1) %ptr, i16 %value syncscope("agent") seq_cst, align 4, !tbaa.struct !5
+ ret i16 %res
+}
+
+define i16 @test_atomicrmw_and_i16_global_agent_align4_preserve_tbaa(ptr addrspace(1) %ptr, i16 %value) {
+; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4_preserve_tbaa(
+; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
+; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !tbaa [[TBAA5:![0-9]+]]
+; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
+; CHECK-NEXT: ret i16 [[EXTRACTED]]
+;
+ %res = atomicrmw and ptr addrspace(1) %ptr, i16 %value syncscope("agent") seq_cst, align 4, !tbaa !6
+ ret i16 %res
+}
+
 define i16 @test_atomicrmw_and_i16_global_agent__amdgpu_no_remote_memory(ptr addrspace(1) %ptr, i16 %value) {
 ; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent__amdgpu_no_remote_memory(
 ; CHECK-NEXT: [[ALIGNEDADDR:%.*]] = call ptr addrspace(1) @llvm.ptrmask.p1.i64(ptr addrspace(1) [[PTR:%.*]], i64 -4)
@@ -223,7 +306,7 @@ define i16 @test_atomicrmw_and_i16_global_agent__amdgpu_no_remote_memory(ptr add
 ; CHECK-NEXT: [[TMP3:%.*]] = zext i16 [[VALUE:%.*]] to i32
 ; CHECK-NEXT: [[VALOPERAND_SHIFTED:%.*]] = shl i32 [[TMP3]], [[SHIFTAMT]]
 ; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[VALOPERAND_SHIFTED]], [[INV_MASK]]
-; CHECK-NEXT: [[TMP4:%.*]] = atomicrmw and ptr addrspace(1) [[ALIGNEDADDR]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4
+; CHECK-NEXT: [[TMP4:%.*]] = atomicrmw and ptr addrspace(1) [[ALIGNEDADDR]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !amdgpu.no.remote.memory [[META8:![0-9]+]]
 ; CHECK-NEXT: [[SHIFTED:%.*]] = lshr i32 [[TMP4]], [[SHIFTAMT]]
 ; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[SHIFTED]] to i16
 ; CHECK-NEXT: ret i16 [[EXTRACTED]]
@@ -236,7 +319,7 @@ define i16 @test_atomicrmw_and_i16_global_agent_align4__amdgpu_no_remote_memory(
 ; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4__amdgpu_no_remote_memory(
 ; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
 ; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
-; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !amdgpu.no.remote.memory [[META8]]
 ; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
 ; CHECK-NEXT: ret i16 [[EXTRACTED]]
 ;
@@ -256,7 +339,7 @@ define i16 @test_atomicrmw_and_i16_global_agent__amdgpu_no_fine_grained_memory(p
 ; CHECK-NEXT: [[TMP3:%.*]] = zext i16 [[VALUE:%.*]] to i32
 ; CHECK-NEXT: [[VALOPERAND_SHIFTED:%.*]] = shl i32 [[TMP3]], [[SHIFTAMT]]
 ; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[VALOPERAND_SHIFTED]], [[INV_MASK]]
-; CHECK-NEXT: [[TMP4:%.*]] = atomicrmw and ptr addrspace(1) [[ALIGNEDADDR]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4
+; CHECK-NEXT: [[TMP4:%.*]] = atomicrmw and ptr addrspace(1) [[ALIGNEDADDR]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !amdgpu.no.fine.grained.memory [[META8]]
 ; CHECK-NEXT: [[SHIFTED:%.*]] = lshr i32 [[TMP4]], [[SHIFTAMT]]
 ; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[SHIFTED]] to i16
 ; CHECK-NEXT: ret i16 [[EXTRACTED]]
@@ -269,7 +352,7 @@ define i16 @test_atomicrmw_and_i16_global_agent_align4__amdgpu_no_fine_grained_m
 ; CHECK-LABEL: @test_atomicrmw_and_i16_global_agent_align4__amdgpu_no_fine_grained_memory(
 ; CHECK-NEXT: [[TMP1:%.*]] = zext i16 [[VALUE:%.*]] to i32
 ; CHECK-NEXT: [[ANDOPERAND:%.*]] = or i32 [[TMP1]], -65536
-; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4
+; CHECK-NEXT: [[TMP2:%.*]] = atomicrmw and ptr addrspace(1) [[PTR:%.*]], i32 [[ANDOPERAND]] syncscope("agent") seq_cst, align 4, !amdgpu.no.fine.grained.memory [[META8]]
 ; CHECK-NEXT: [[EXTRACTED:%.*]] = trunc i32 [[TMP2]] to i16
 ; CHECK-NEXT: ret i16 [[EXTRACTED]]
 ;
@@ -1180,6 +1263,15 @@ define bfloat @test_atomicrmw_xchg_bf16_global_agent_align4(ptr addrspace(1) %pt
 }
 
 !0 = !{}
+!1 = !{!"foo", !"bar"}
+!2 = !{!3}
+!3 = distinct !{!3, !4}
+!4 = distinct !{!4}
+!5 = !{i64 0, i64 4, !1, i64 8, i64 4}
+!6 = !{!7, !7, i64 0}
+!7 = !{!"omnipotent char", !8, i64 0}
+!8 = !{!"Simple C/C++ TBAA"}
+
 ;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
 ; BASE: {{.*}}
 ; GCN: {{.*}}