Fix include guards and add tests for OpToFuncCallLowering.

PiperOrigin-RevId: 276859463

1 files changed, 14 insertions, 6 deletions

diff --git a/mlir/lib/Conversion/GPUCommon/OpToFuncCallLowering.h b/mlir/lib/Conversion/GPUCommon/OpToFuncCallLowering.h
index 0622dc61b9d..4c083f98230 100644
--- a/mlir/lib/Conversion/GPUCommon/OpToFuncCallLowering.h
+++ b/mlir/lib/Conversion/GPUCommon/OpToFuncCallLowering.h
@@ -14,8 +14,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 // =============================================================================
-#ifndef THIRD_PARTY_LLVM_LLVM_PROJECTS_GOOGLE_MLIR_LIB_CONVERSION_GPUCOMMON_OPTOFUNCCALLLOWERING_H_
-#define THIRD_PARTY_LLVM_LLVM_PROJECTS_GOOGLE_MLIR_LIB_CONVERSION_GPUCOMMON_OPTOFUNCCALLLOWERING_H_
+#ifndef MLIR_CONVERSION_GPUCOMMON_OPTOFUNCCALLLOWERING_H_
+#define MLIR_CONVERSION_GPUCOMMON_OPTOFUNCCALLLOWERING_H_
 
 #include "mlir/Conversion/StandardToLLVM/ConvertStandardToLLVM.h"
 #include "mlir/Dialect/GPU/GPUDialect.h"
@@ -26,6 +26,15 @@
 
 namespace mlir {
 
+/// Rewriting that replace SourceOp with a CallOp to `f32Func` or `f64Func`
+/// depending on the element type that Op operates upon. The function
+/// declaration is added in case it was not added before.
+///
+/// Example with NVVM:
+///   %exp_f32 = std.exp %arg_f32 : f32
+///
+/// will be transformed into
+///   llvm.call @__nv_expf(%arg_f32) : (!llvm.float) -> !llvm.float
 template <typename SourceOp>
 struct OpToFuncCallLowering : public LLVMOpLowering {
 public:
@@ -48,10 +57,9 @@ public:
     LLVMType resultType = lowering.convertType(op->getResult(0)->getType())
                               .template cast<LLVM::LLVMType>();
     LLVMType funcType = getFunctionType(resultType, operands);
-    const std::string funcName = getFunctionName(resultType);
-    if (funcName.empty()) {
+    StringRef funcName = getFunctionName(resultType);
+    if (funcName.empty())
       return matchFailure();
-    }
 
     LLVMFuncOp funcOp = appendOrGetFuncOp(funcName, funcType, op);
     auto callOp = rewriter.create<LLVM::CallOp>(
@@ -100,4 +108,4 @@ private:
 
 } // namespace mlir
 
-#endif // THIRD_PARTY_LLVM_LLVM_PROJECTS_GOOGLE_MLIR_LIB_CONVERSION_GPUCOMMON_OPTOFUNCCALLLOWERING_H_
+#endif // MLIR_CONVERSION_GPUCOMMON_OPTOFUNCCALLLOWERING_H_