[llvm] [SPIR-V] Honor explicit memory_order/memory_scope in atomic load/store (PR #215572)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-spir-v

Author: Arseniy Obolenskiy (aobolensk)

<details>
<summary>Changes</summary>

atomic_load_explicit and atomic_store_explicit ignored their memory_order/memory_scope arguments

Translate the explicit arguments via the existing buildMemSemanticsReg/buildScopeReg helpers, as buildAtomicRMWInst already does

---
Full diff: https://github.com/llvm/llvm-project/pull/215572.diff


2 Files Affected:

- (modified) llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp (+24-20) 
- (modified) llvm/test/CodeGen/SPIRV/AtomicBuiltinsFloat.ll (+12-3) 


``````````diff
diff --git a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
index 89b0292bc656b..38c770aed5836 100644
--- a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
@@ -635,24 +635,22 @@ static bool buildAtomicLoadInst(const SPIRV::IncomingCall *Call,
   if (Call->isSpirvOp())
     return buildOpFromWrapper(MIRBuilder, SPIRV::OpAtomicLoad, Call, TypeReg);
 
+  // atomic_load_explicit(ptr, memory_order[, memory_scope]).
   Register PtrRegister = Call->Arguments[0];
-  // TODO: if true insert call to __translate_ocl_memory_sccope before
-  // OpAtomicLoad and the function implementation. We can use Translator's
-  // output for transcoding/atomic_explicit_arguments.cl as an example.
+  MachineRegisterInfo *MRI = MIRBuilder.getMRI();
+
+  unsigned Semantics =
+      SPIRV::MemorySemantics::SequentiallyConsistent |
+      getMemSemanticsForStorageClass(GR->getPointerStorageClass(PtrRegister));
+  Register MemSemanticsReg =
+      Call->Arguments.size() >= 2 ? Call->Arguments[1] : Register();
+  MemSemanticsReg = buildMemSemanticsReg(MemSemanticsReg, PtrRegister,
+                                         Semantics, MIRBuilder, GR);
+
   Register ScopeRegister =
-      Call->Arguments.size() > 1
-          ? Call->Arguments[1]
-          : buildConstantIntReg32(SPIRV::Scope::Device, MIRBuilder, GR);
-  Register MemSemanticsReg;
-  if (Call->Arguments.size() > 2) {
-    // TODO: Insert call to __translate_ocl_memory_order before OpAtomicLoad.
-    MemSemanticsReg = Call->Arguments[2];
-  } else {
-    int Semantics =
-        SPIRV::MemorySemantics::SequentiallyConsistent |
-        getMemSemanticsForStorageClass(GR->getPointerStorageClass(PtrRegister));
-    MemSemanticsReg = buildConstantIntReg32(Semantics, MIRBuilder, GR);
-  }
+      Call->Arguments.size() >= 3 ? Call->Arguments[2] : Register();
+  ScopeRegister =
+      buildScopeReg(ScopeRegister, SPIRV::Scope::Device, MIRBuilder, GR, MRI);
 
   MIRBuilder.buildInstr(SPIRV::OpAtomicLoad)
       .addDef(Call->ReturnRegister)
@@ -671,13 +669,19 @@ static bool buildAtomicStoreInst(const SPIRV::IncomingCall *Call,
     return buildOpFromWrapper(MIRBuilder, SPIRV::OpAtomicStore, Call,
                               Register(0));
 
-  Register ScopeRegister =
-      buildConstantIntReg32(SPIRV::Scope::Device, MIRBuilder, GR);
+  MachineRegisterInfo *MRI = MIRBuilder.getMRI();
   Register PtrRegister = Call->Arguments[0];
-  int Semantics =
+  unsigned Semantics =
       SPIRV::MemorySemantics::SequentiallyConsistent |
       getMemSemanticsForStorageClass(GR->getPointerStorageClass(PtrRegister));
-  Register MemSemanticsReg = buildConstantIntReg32(Semantics, MIRBuilder, GR);
+  Register MemSemanticsReg =
+      Call->Arguments.size() >= 3 ? Call->Arguments[2] : Register();
+  MemSemanticsReg = buildMemSemanticsReg(MemSemanticsReg, PtrRegister,
+                                         Semantics, MIRBuilder, GR);
+  Register ScopeRegister =
+      Call->Arguments.size() >= 4 ? Call->Arguments[3] : Register();
+  ScopeRegister =
+      buildScopeReg(ScopeRegister, SPIRV::Scope::Device, MIRBuilder, GR, MRI);
   MIRBuilder.buildInstr(SPIRV::OpAtomicStore)
       .addUse(PtrRegister)
       .addUse(ScopeRegister)
diff --git a/llvm/test/CodeGen/SPIRV/AtomicBuiltinsFloat.ll b/llvm/test/CodeGen/SPIRV/AtomicBuiltinsFloat.ll
index cb81df5b61019..4c41fe3c92694 100644
--- a/llvm/test/CodeGen/SPIRV/AtomicBuiltinsFloat.ll
+++ b/llvm/test/CodeGen/SPIRV/AtomicBuiltinsFloat.ll
@@ -3,12 +3,21 @@
 
 ;; Types:
 ; CHECK:         %[[#F32:]] = OpTypeFloat 32
+; CHECK:         %[[#I32:]] = OpTypeInt 32 0
 ;; Constants:
-; CHECK:         %[[#CONST:]] = OpConstant %[[#F32]] 1
+; CHECK-DAG:     %[[#CONST:]] = OpConstant %[[#F32]] 1
+; CHECK-DAG:     %[[#RELAXED:]] = OpConstantNull %[[#I32]]
+; CHECK-DAG:     %[[#DEVICE:]] = OpConstant %[[#I32]] 1
+; CHECK-DAG:     %[[#WORKGROUP:]] = OpConstant %[[#I32]] 2
+; CHECK-DAG:     %[[#SEQCST:]] = OpConstant %[[#I32]] 16
 ;; Atomic instructions:
 ; CHECK:         OpStore %[[#]] %[[#CONST]]
-; CHECK-COUNT-3: OpAtomicStore
-; CHECK-COUNT-3: OpAtomicLoad
+; CHECK:         OpAtomicStore %[[#]] %[[#DEVICE]] %[[#SEQCST]] %[[#CONST]]
+; CHECK:         OpAtomicStore %[[#]] %[[#DEVICE]] %[[#RELAXED]] %[[#CONST]]
+; CHECK:         OpAtomicStore %[[#]] %[[#WORKGROUP]] %[[#RELAXED]] %[[#CONST]]
+; CHECK:         OpAtomicLoad %[[#]] %[[#]] %[[#DEVICE]] %[[#SEQCST]]
+; CHECK:         OpAtomicLoad %[[#]] %[[#]] %[[#DEVICE]] %[[#RELAXED]]
+; CHECK:         OpAtomicLoad %[[#]] %[[#]] %[[#WORKGROUP]] %[[#RELAXED]]
 ; CHECK-COUNT-3: OpAtomicExchange
 
 define spir_kernel void @test_atomic_kernel(ptr addrspace(3) %ff) local_unnamed_addr #0 !kernel_arg_addr_space !3 !kernel_arg_access_qual !4 !kernel_arg_type !5 !kernel_arg_base_type !6 !kernel_arg_type_qual !7 {

``````````

</details>


https://github.com/llvm/llvm-project/pull/215572