[Mlir-commits] [mlir] [mlir][spirv] Add gpu printf op lowering to spirv.CL.printf op (PR #78510)
Jakub Kuderski
llvmlistbot at llvm.org
Wed Sep 18 06:50:46 PDT 2024
================
@@ -597,6 +606,120 @@ class GPUSubgroupReduceConversion final
}
};
+/// Pattern to convert a gpu.printf op into a SPIR-V CLPrintf op.
+
+LogicalResult GPUPrintfConversion::matchAndRewrite(
+ gpu::PrintfOp gpuPrintfOp, OpAdaptor adaptor,
+ ConversionPatternRewriter &rewriter) const {
+
+ Location loc = gpuPrintfOp.getLoc();
+
+ auto moduleOp = gpuPrintfOp->getParentOfType<spirv::ModuleOp>();
+
+ if (!moduleOp) {
+ return success();
+ }
+
+ const char formatStringPrefix[] = "printfMsg";
+ unsigned stringNumber = 0;
+ SmallString<16> globalVarName;
+ spirv::GlobalVariableOp globalVar;
+
+ // SPIR-V global variable is used to initialize printf
+ // format string value, if there are multiple printf messages,
+ // each global var needs to be created with a unique name.
+ // like printfMsg0, printfMsg1, ...
+ // Formulate unique global variable name after
+ // searching in the module for existing global variable names.
+ // This is to avoid name collision with existing global variables.
+ do {
+ globalVarName.clear();
+ (formatStringPrefix + llvm::Twine(stringNumber++))
+ .toStringRef(globalVarName);
+ } while (moduleOp.lookupSymbol(globalVarName));
+
+ IntegerType i8Type = rewriter.getI8Type();
+ IntegerType i32Type = rewriter.getI32Type();
+
+ // Each character of printf format string is
+ // stored as a spec constant. We need to create
+ // unique name for this spec constant like
+ // @printfMsg0_sc0, @printfMsg0_sc1, ... by searching in the module
+ // for existing spec constant names.
+ unsigned specConstantNum = 0;
+ auto createSpecConstant = [&](unsigned value) {
+ auto attr = rewriter.getI8IntegerAttr(value);
+ SmallString<16> specCstName;
+ (llvm::Twine(globalVarName) + "_sc" + llvm::Twine(specConstantNum++))
+ .toStringRef(specCstName);
+
+ return rewriter.create<spirv::SpecConstantOp>(
+ loc, rewriter.getStringAttr(specCstName), attr);
+ };
----------------
kuhar wrote:
Similar here: could we outline this code to a helper function?
https://github.com/llvm/llvm-project/pull/78510
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