[TritonIR] simplify Load/StoreOps when mask is true/false (#79)

* [TritonIR] fix Load/Store/CopyAsyncOp's parsers

* [TritonIR] simplify Load/StoreOps when mask is true/false

* [TEST] adds tests to check load/store simplification

lib/Dialect/Triton/IR/Ops.cpp

@@ -36,6 +36,68 @@ static Type getPointerTypeFromTensor(Type type) {
   return Type();
 }
 
+// Parser & printer for assembly forms
+ParseResult parseLoadOp(OpAsmParser &parser, OperationState &result) {
+  SmallVector<OpAsmParser::OperandType, 4> allOperands;
+  Type resultTypes[1];
+  SMLoc allOperandLoc = parser.getCurrentLocation();
+  if (parser.parseOperandList(allOperands) ||
+      parser.parseOptionalAttrDict(result.attributes) || parser.parseColon() ||
+      parser.parseCustomTypeWithFallback(resultTypes[0]))
+    return failure();
+
+  result.addTypes(resultTypes);
+
+  SmallVector<Type> operandTypes;
+  operandTypes.push_back(getPointerTypeFromTensor(resultTypes[0])); // ptr
+  if (allOperands.size() >= 2)
+    operandTypes.push_back(getI1SameShape(resultTypes[0])); // mask
+  if (allOperands.size() >= 3)
+    operandTypes.push_back(resultTypes[0]); // other
+
+  if (parser.resolveOperands(allOperands, operandTypes, allOperandLoc,
+                             result.operands))
+    return failure();
+  return success();
+}
+
+void printLoadOp(OpAsmPrinter &printer, LoadOp loadOp) {
+  printer << " ";
+  printer << loadOp.getOperation()->getOperands();
+  printer.printOptionalAttrDict(loadOp->getAttrs(), /*elidedAttrs=*/{});
+  printer << " : ";
+  printer.printStrippedAttrOrType(loadOp.result().getType());
+}
+
+ParseResult parseStoreOp(OpAsmParser &parser, OperationState &result) {
+  SmallVector<OpAsmParser::OperandType, 4> allOperands;
+  Type valueType;
+  SMLoc allOperandLoc = parser.getCurrentLocation();
+  if (parser.parseOperandList(allOperands) ||
+      parser.parseOptionalAttrDict(result.attributes) || parser.parseColon() ||
+      parser.parseCustomTypeWithFallback(valueType))
+    return failure();
+
+  SmallVector<Type> operandTypes;
+  operandTypes.push_back(getPointerTypeFromTensor(valueType)); // ptr
+  operandTypes.push_back(valueType);                           // value
+  if (allOperands.size() >= 3)
+    operandTypes.push_back(getI1SameShape(valueType)); // mask
+
+  if (parser.resolveOperands(allOperands, operandTypes, allOperandLoc,
+                             result.operands))
+    return failure();
+  return success();
+}
+
+void printStoreOp(OpAsmPrinter &printer, StoreOp storeOp) {
+  printer << " ";
+  printer << storeOp.getOperation()->getOperands();
+  printer.printOptionalAttrDict(storeOp->getAttrs(), /*elidedAttrs=*/{});
+  printer << " : ";
+  printer.printStrippedAttrOrType(storeOp.value().getType());
+}
+
 } // namespace triton
 } // namespace mlir
 

lib/Dialect/Triton/Transforms/Combine.cpp

@@ -92,6 +92,91 @@ public:
   }
 };
 
+// load(ptr, splat(1), ...)        -> load(ptr, ...)
+// load(ptr, splat(0), other, ...) -> other
+struct CanonicalizeMaskedLoadPattern
+    : public mlir::OpRewritePattern<triton::LoadOp> {
+  CanonicalizeMaskedLoadPattern(mlir::MLIRContext *context)
+      : OpRewritePattern<triton::LoadOp>(context, 1) {}
+
+  mlir::LogicalResult
+  matchAndRewrite(triton::LoadOp loadOp,
+                  mlir::PatternRewriter &rewriter) const override {
+    auto mask = loadOp.mask();
+    if (!mask)
+      return mlir::failure();
+
+    auto constantMask = llvm::dyn_cast<arith::ConstantOp>(mask.getDefiningOp());
+    if (!constantMask)
+      return mlir::failure();
+
+    auto splatMask = constantMask.getValue().dyn_cast<SplatElementsAttr>();
+    if (!splatMask)
+      return mlir::failure();
+
+    if (splatMask.getSplatValue<IntegerAttr>().getValue() == true) {
+      // mask = splat(1)
+      rewriter.replaceOpWithNewOp<triton::LoadOp>(
+          loadOp, loadOp.getType(), loadOp.ptr(), Value(), Value(),
+          loadOp.cache(), loadOp.evict(), loadOp.isVolatile());
+    } else {
+      // mask = splat(0)
+
+      // If there's no "other", the value is "undef".  Perhaps we want to
+      // optimize it in the future.x
+      auto otherVal = loadOp.other();
+      if (!otherVal)
+        return mlir::failure();
+      rewriter.replaceOp(loadOp, otherVal);
+    }
+    return mlir::success();
+  }
+};
+
+void triton::LoadOp::getCanonicalizationPatterns(RewritePatternSet &results,
+                                                 MLIRContext *context) {
+  results.add<CanonicalizeMaskedLoadPattern>(context);
+}
+
+// store(ptr, value, splat(1), ...) -> store(ptr, value, ...)
+// store(ptr, value, splat(0), ...) -> [none]
+struct CanonicalizeMaskedStorePattern
+    : public mlir::OpRewritePattern<triton::StoreOp> {
+  CanonicalizeMaskedStorePattern(mlir::MLIRContext *context)
+      : OpRewritePattern<triton::StoreOp>(context, 1) {}
+
+  mlir::LogicalResult
+  matchAndRewrite(triton::StoreOp storeOp,
+                  mlir::PatternRewriter &rewriter) const override {
+    auto mask = storeOp.mask();
+    if (!mask)
+      return mlir::failure();
+
+    auto constantMask = llvm::dyn_cast<arith::ConstantOp>(mask.getDefiningOp());
+    if (!constantMask)
+      return mlir::failure();
+
+    auto splatMask = constantMask.getValue().dyn_cast<SplatElementsAttr>();
+    if (!splatMask)
+      return mlir::failure();
+
+    if (splatMask.getSplatValue<IntegerAttr>().getValue() == true) {
+      // mask = splat(1)
+      rewriter.replaceOpWithNewOp<triton::StoreOp>(storeOp, storeOp.ptr(),
+                                                   storeOp.value());
+    } else {
+      // mask = splat(0)
+      rewriter.eraseOp(storeOp);
+    }
+    return mlir::success();
+  }
+};
+
+void triton::StoreOp::getCanonicalizationPatterns(RewritePatternSet &results,
+                                                  MLIRContext *context) {
+  results.add<CanonicalizeMaskedStorePattern>(context);
+}
+
 #define GEN_PASS_CLASSES
 #include "triton/Dialect/Triton/Transforms/Passes.h.inc"