Try to fold operations in DialectConversion when trying to legalize.

This change allows for DialectConversion to attempt folding as a mechanism to legalize illegal operations. This also expands folding support in OpBuilder::createOrFold to generate new constants when folding, and also enables it to work in the context of a PatternRewriter.

PiperOrigin-RevId: 285448440

1 files changed, 13 insertions, 16 deletions

diff --git a/mlir/test/Conversion/StandardToLLVM/convert-to-llvmir.mlir b/mlir/test/Conversion/StandardToLLVM/convert-to-llvmir.mlir
index 9d8b04797ba..14e46aabc56 100644
--- a/mlir/test/Conversion/StandardToLLVM/convert-to-llvmir.mlir
+++ b/mlir/test/Conversion/StandardToLLVM/convert-to-llvmir.mlir
@@ -364,9 +364,8 @@ func @multireturn_caller() {
   return
 }
 
-// CHECK-LABEL: func @vector_ops(%arg0: !llvm<"<4 x float>">, %arg1: !llvm<"<4 x i1>">, %arg2: !llvm<"<4 x i64>">) -> !llvm<"<4 x float>"> {
-func @vector_ops(vector<4xf32>, vector<4xi1>, vector<4xi64>) -> vector<4xf32> {
-^bb0(%arg0: vector<4xf32>, %arg1: vector<4xi1>, %arg2: vector<4xi64>):
+// CHECK-LABEL: func @vector_ops(%arg0: !llvm<"<4 x float>">, %arg1: !llvm<"<4 x i1>">, %arg2: !llvm<"<4 x i64>">, %arg3: !llvm<"<4 x i64>">) -> !llvm<"<4 x float>"> {
+func @vector_ops(%arg0: vector<4xf32>, %arg1: vector<4xi1>, %arg2: vector<4xi64>, %arg3: vector<4xi64>) -> vector<4xf32> {
 // CHECK-NEXT:  %0 = llvm.mlir.constant(dense<4.200000e+01> : vector<4xf32>) : !llvm<"<4 x float>">
   %0 = constant dense<42.> : vector<4xf32>
 // CHECK-NEXT:  %1 = llvm.fadd %arg0, %0 : !llvm<"<4 x float>">
@@ -383,12 +382,12 @@ func @vector_ops(vector<4xf32>, vector<4xi1>, vector<4xi64>) -> vector<4xf32> {
   %7 = divf %arg0, %0 : vector<4xf32>
 // CHECK-NEXT:  %7 = llvm.frem %arg0, %0 : !llvm<"<4 x float>">
   %8 = remf %arg0, %0 : vector<4xf32>
-// CHECK-NEXT:  %8 = llvm.and %arg2, %arg2 : !llvm<"<4 x i64>">
-  %9 = and %arg2, %arg2 : vector<4xi64>
-// CHECK-NEXT:  %9 = llvm.or %arg2, %arg2 : !llvm<"<4 x i64>">
-  %10 = or %arg2, %arg2 : vector<4xi64>
-// CHECK-NEXT:  %10 = llvm.xor %arg2, %arg2 : !llvm<"<4 x i64>">
-  %11 = xor %arg2, %arg2 : vector<4xi64>
+// CHECK-NEXT:  %8 = llvm.and %arg2, %arg3 : !llvm<"<4 x i64>">
+  %9 = and %arg2, %arg3 : vector<4xi64>
+// CHECK-NEXT:  %9 = llvm.or %arg2, %arg3 : !llvm<"<4 x i64>">
+  %10 = or %arg2, %arg3 : vector<4xi64>
+// CHECK-NEXT:  %10 = llvm.xor %arg2, %arg3 : !llvm<"<4 x i64>">
+  %11 = xor %arg2, %arg3 : vector<4xi64>
   return %1 : vector<4xf32>
 }
 
@@ -498,23 +497,21 @@ func @integer_extension_and_truncation() {
 }
 
 // CHECK-LABEL: @dfs_block_order
-func @dfs_block_order() -> (i32) {
-// CHECK-NEXT:  %0 = llvm.mlir.constant(42 : i32) : !llvm.i32
+func @dfs_block_order(%arg0: i32) -> (i32) {
+// CHECK-NEXT:  %[[CST:.*]] = llvm.mlir.constant(42 : i32) : !llvm.i32
   %0 = constant 42 : i32
 // CHECK-NEXT:  llvm.br ^bb2
   br ^bb2
 
 // CHECK-NEXT: ^bb1:
-// CHECK-NEXT:  %1 = llvm.add %0, %2 : !llvm.i32
-// CHECK-NEXT:  llvm.return %1 : !llvm.i32
+// CHECK-NEXT:  %[[ADD:.*]] = llvm.add %arg0, %[[CST]] : !llvm.i32
+// CHECK-NEXT:  llvm.return %[[ADD]] : !llvm.i32
 ^bb1:
-  %2 = addi %0, %1 : i32
+  %2 = addi %arg0, %0 : i32
   return %2 : i32
 
 // CHECK-NEXT: ^bb2:
 ^bb2:
-// CHECK-NEXT:  %2 = llvm.mlir.constant(55 : i32) : !llvm.i32
-  %1 = constant 55 : i32
 // CHECK-NEXT:  llvm.br ^bb1
   br ^bb1
 }