[Mlir-commits] [mlir] [mlir][llvm] Changes to support amd gpu unsafe floating point operations. (PR #139801)
llvmlistbot at llvm.org
llvmlistbot at llvm.org
Wed May 14 10:09:59 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-mlir-llvm
Author: Anchu Rajendran S (anchuraj)
<details>
<summary>Changes</summary>
adds function attribute "amdgpu-unsafe-fp-atomics". This allows amdgpu backend to use
unsafe fp atomic instructions in these functions.
---
Full diff: https://github.com/llvm/llvm-project/pull/139801.diff
6 Files Affected:
- (modified) mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td (+1)
- (modified) mlir/lib/Target/LLVMIR/ModuleImport.cpp (+5)
- (modified) mlir/lib/Target/LLVMIR/ModuleTranslation.cpp (+4)
- (modified) mlir/test/Dialect/LLVMIR/func.mlir (+6)
- (modified) mlir/test/Target/LLVMIR/Import/function-attributes.ll (+6)
- (modified) mlir/test/Target/LLVMIR/llvmir.mlir (+9)
``````````diff
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
index f19f9d5a3083c..93f754607fdac 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -1899,6 +1899,7 @@ def LLVM_LLVMFuncOp : LLVM_Op<"func", [
OptionalAttr<BoolAttr>:$no_nans_fp_math,
OptionalAttr<BoolAttr>:$approx_func_fp_math,
OptionalAttr<BoolAttr>:$no_signed_zeros_fp_math,
+ OptionalAttr<BoolAttr>:$amdgpu_unsafe_fp_atomics,
OptionalAttr<StrAttr>:$denormal_fp_math,
OptionalAttr<StrAttr>:$denormal_fp_math_f32,
OptionalAttr<StrAttr>:$fp_contract,
diff --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index 0b77a3d23d392..1b18e2e5c3a89 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -2140,6 +2140,7 @@ static constexpr std::array kExplicitAttributes{
StringLiteral("aarch64_pstate_sm_body"),
StringLiteral("aarch64_pstate_sm_compatible"),
StringLiteral("aarch64_pstate_sm_enabled"),
+ StringLiteral("amdgpu-unsafe-fp-atomics"),
StringLiteral("alwaysinline"),
StringLiteral("approx-func-fp-math"),
StringLiteral("convergent"),
@@ -2318,6 +2319,10 @@ void ModuleImport::processFunctionAttributes(llvm::Function *func,
attr.isStringAttribute())
funcOp.setNoSignedZerosFpMath(attr.getValueAsBool());
+ if (llvm::Attribute attr = func->getFnAttribute("amdgpu-unsafe-fp-atomics");
+ attr.isStringAttribute())
+ funcOp.setAmdgpuUnsafeFpAtomics(attr.getValueAsBool());
+
if (llvm::Attribute attr = func->getFnAttribute("denormal-fp-math");
attr.isStringAttribute())
funcOp.setDenormalFpMathAttr(
diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index ad4f65da9d7f5..bf8d9f74318b3 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -1496,6 +1496,10 @@ LogicalResult ModuleTranslation::convertOneFunction(LLVMFuncOp func) {
else if (func.getArmPreservesZa())
llvmFunc->addFnAttr("aarch64_preserves_za");
+ if (auto amdgpuUnsafeFpAtomics = func.getAmdgpuUnsafeFpAtomics())
+ llvmFunc->addFnAttr("amdgpu-unsafe-fp-atomics",
+ llvm::toStringRef(*amdgpuUnsafeFpAtomics));
+
if (auto targetCpu = func.getTargetCpu())
llvmFunc->addFnAttr("target-cpu", *targetCpu);
diff --git a/mlir/test/Dialect/LLVMIR/func.mlir b/mlir/test/Dialect/LLVMIR/func.mlir
index a168cebff019b..90a24b5f4a40e 100644
--- a/mlir/test/Dialect/LLVMIR/func.mlir
+++ b/mlir/test/Dialect/LLVMIR/func.mlir
@@ -236,6 +236,12 @@ module {
llvm.return
}
+ llvm.func @amdgpu_fp_unsafe_atomics() attributes {amdgpu_fp_unsafe_atomics = true} {
+ // CHECK: @amdgpu_fp_unsafe_atomics
+ // CHECK-SAME: attributes {amdgpu_fp_unsafe_atomics = true}
+ llvm.return
+ }
+
// CHECK: llvm.comdat @__llvm_comdat
llvm.comdat @__llvm_comdat {
// CHECK: llvm.comdat_selector @any any
diff --git a/mlir/test/Target/LLVMIR/Import/function-attributes.ll b/mlir/test/Target/LLVMIR/Import/function-attributes.ll
index 0b13645853cea..e9f8b707b85a7 100644
--- a/mlir/test/Target/LLVMIR/Import/function-attributes.ll
+++ b/mlir/test/Target/LLVMIR/Import/function-attributes.ll
@@ -267,6 +267,12 @@ define void @arm_preserves_za_func() "aarch64_preserves_za" {
ret void
}
+; // -----
+
+; CHECK-LABEL: @func_attr_amdgpu_unsafe_fp_atomics_true
+; CHECK-SAME: attributes {amdgpu_unsafe_fp_atomics = true}
+declare void @func_attr_amdgpu_unsafe_fp_atomics_true() "amdgpu-unsafe-fp-atomics"="true"
+
// -----
; CHECK-LABEL: @section_func
diff --git a/mlir/test/Target/LLVMIR/llvmir.mlir b/mlir/test/Target/LLVMIR/llvmir.mlir
index 9852c4051f0d0..ade6cbf505e9e 100644
--- a/mlir/test/Target/LLVMIR/llvmir.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir.mlir
@@ -2474,6 +2474,15 @@ llvm.func @preserves_za_func() attributes {arm_preserves_za} {
// -----
+// CHECK-LABEL: @amdgpu_unsafe_fp_atomics_func
+// CHECK-SAME: #[[ATTR:[0-9]*]]
+llvm.func @amdgpu_unsafe_fp_atomics_func() attributes {amdgpu_unsafe_fp_atomics = true} {
+ llvm.return
+}
+// CHECK: #[[ATTR]] = { "amdgpu-unsafe-fp-atomics"="true" }
+
+// -----
+
//
// frame pointer attribute.
//
``````````
</details>
https://github.com/llvm/llvm-project/pull/139801
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