[mlir] [arith] add shl overflow flag in Arith and lower to SPIR-V and LLVMIR (#79828)

There is no `SHL` used in canonicalization in `arith`

---------

Co-authored-by: Jakub Kuderski <[email protected]>
Co-authored-by: Tobias Gysi <[email protected]>

Author: 3 people

mlir/include/mlir/Dialect/Arith/IR/ArithOps.td

@@ -782,7 +782,7 @@ def Arith_XOrIOp : Arith_TotalIntBinaryOp<"xori", [Commutative]> {
 // ShLIOp
 //===----------------------------------------------------------------------===//
 
-def Arith_ShLIOp : Arith_TotalIntBinaryOp<"shli"> {
+def Arith_ShLIOp : Arith_IntBinaryOpWithOverflowFlags<"shli"> {
   let summary = "integer left-shift";
   let description = [{
     The `shli` operation shifts the integer value of the first operand to the left 
@@ -791,12 +791,18 @@ def Arith_ShLIOp : Arith_TotalIntBinaryOp<"shli"> {
     operand is greater than the bitwidth of the first operand, then the 
     operation returns poison.
 
+    This op supports `nuw`/`nsw` overflow flags which stands stand for
+    "No Unsigned Wrap" and "No Signed Wrap", respectively. If the `nuw` and/or
+    `nsw` flags are present, and an unsigned/signed overflow occurs
+    (respectively), the result is poison.
+
     Example:
 
     ```mlir
-    %1 = arith.constant 5 : i8                 // %1 is 0b00000101
+    %1 = arith.constant 5 : i8  // %1 is 0b00000101
     %2 = arith.constant 3 : i8
-    %3 = arith.shli %1, %2 : (i8, i8) -> i8    // %3 is 0b00101000
+    %3 = arith.shli %1, %2 : i8 // %3 is 0b00101000
+    %4 = arith.shli %1, %2 overflow<nsw, nuw> : i8  
     ```
   }];
   let hasFolder = 1;

mlir/lib/Conversion/ArithToLLVM/ArithToLLVM.cpp

@@ -96,7 +96,9 @@ using RemUIOpLowering =
     VectorConvertToLLVMPattern<arith::RemUIOp, LLVM::URemOp>;
 using SelectOpLowering =
     VectorConvertToLLVMPattern<arith::SelectOp, LLVM::SelectOp>;
-using ShLIOpLowering = VectorConvertToLLVMPattern<arith::ShLIOp, LLVM::ShlOp>;
+using ShLIOpLowering =
+    VectorConvertToLLVMPattern<arith::ShLIOp, LLVM::ShlOp,
+                               arith::AttrConvertOverflowToLLVM>;
 using ShRSIOpLowering =
     VectorConvertToLLVMPattern<arith::ShRSIOp, LLVM::AShrOp>;
 using ShRUIOpLowering =

mlir/lib/Conversion/ArithToSPIRV/ArithToSPIRV.cpp

@@ -1217,7 +1217,7 @@ void mlir::arith::populateArithToSPIRVPatterns(
     BitwiseOpPattern<arith::AndIOp, spirv::LogicalAndOp, spirv::BitwiseAndOp>,
     BitwiseOpPattern<arith::OrIOp, spirv::LogicalOrOp, spirv::BitwiseOrOp>,
     XOrIOpLogicalPattern, XOrIOpBooleanPattern,
-    spirv::ElementwiseOpPattern<arith::ShLIOp, spirv::ShiftLeftLogicalOp>,
+    ElementwiseArithOpPattern<arith::ShLIOp, spirv::ShiftLeftLogicalOp>,
     spirv::ElementwiseOpPattern<arith::ShRUIOp, spirv::ShiftRightLogicalOp>,
     spirv::ElementwiseOpPattern<arith::ShRSIOp, spirv::ShiftRightArithmeticOp>,
     spirv::ElementwiseOpPattern<arith::NegFOp, spirv::FNegateOp>,

mlir/test/Conversion/ArithToLLVM/arith-to-llvm.mlir

@@ -586,5 +586,7 @@ func.func @ops_supporting_overflow(%arg0: i64, %arg1: i64) {
   %1 = arith.subi %arg0, %arg1 overflow<nuw> : i64
   // CHECK: %{{.*}} = llvm.mul %{{.*}}, %{{.*}} overflow<nsw, nuw> : i64
   %2 = arith.muli %arg0, %arg1 overflow<nsw, nuw> : i64
+  // CHECK: %{{.*}} = llvm.shl %{{.*}}, %{{.*}} overflow<nsw, nuw> : i64
+  %3 = arith.shli %arg0, %arg1 overflow<nsw, nuw> : i64
   return
 }

mlir/test/Conversion/ArithToSPIRV/arith-to-spirv.mlir

@@ -1422,6 +1422,8 @@ func.func @ops_flags(%arg0: i64, %arg1: i64) {
   %1 = arith.subi %arg0, %arg1 overflow<nuw> : i64
   // CHECK: %{{.*}} = spirv.IMul %{{.*}}, %{{.*}} {no_signed_wrap, no_unsigned_wrap} : i64
   %2 = arith.muli %arg0, %arg1 overflow<nsw, nuw> : i64
+  // CHECK: %{{.*}} = spirv.ShiftLeftLogical %{{.*}}, %{{.*}} {no_signed_wrap, no_unsigned_wrap} : i64
+  %3 = arith.shli %arg0, %arg1 overflow<nsw, nuw> : i64
   return
 }
 
@@ -1443,6 +1445,8 @@ func.func @ops_flags(%arg0: i64, %arg1: i64) {
   %1 = arith.subi %arg0, %arg1 overflow<nuw> : i64
   // CHECK: %{{.*}} = spirv.IMul %{{.*}}, %{{.*}} : i64
   %2 = arith.muli %arg0, %arg1 overflow<nsw, nuw> : i64
+  // CHECK: %{{.*}} = spirv.IMul %{{.*}}, %{{.*}} : i64
+  %3 = arith.muli %arg0, %arg1 overflow<nsw, nuw> : i64
   return
 }
 

mlir/test/Dialect/Arith/ops.mlir

@@ -1147,5 +1147,7 @@ func.func @intflags_func(%arg0: i64, %arg1: i64) {
   %1 = arith.subi %arg0, %arg1 overflow<nuw> : i64
   // CHECK: %{{.*}} = arith.muli %{{.*}}, %{{.*}} overflow<nsw, nuw> : i64
   %2 = arith.muli %arg0, %arg1 overflow<nsw, nuw> : i64
+  // CHECK: %{{.*}} = arith.shli %{{.*}}, %{{.*}} overflow<nsw, nuw> : i64
+  %3 = arith.shli %arg0, %arg1 overflow<nsw, nuw> : i64
   return
 }