[Mlir-commits] [mlir] c52a5f2 - MLIR][STD] Fold trunci (sexti).

[llvmlistbot at llvm.org]

Author: KareemErgawy-TomTom
Date: 2021-03-29T08:34:08+02:00
New Revision: c52a5f2aa7966ec6a7acec8e4d026093c927f22c

URL: https://github.com/llvm/llvm-project/commit/c52a5f2aa7966ec6a7acec8e4d026093c927f22c
DIFF: https://github.com/llvm/llvm-project/commit/c52a5f2aa7966ec6a7acec8e4d026093c927f22c.diff

LOG: MLIR][STD] Fold trunci (sexti).

This patch folds the following pattern:

```
%arg0 = ...
%0 = sexti %arg0 : i1 to i8
%1 = trunci %0 : i8 to i1
```

into just `%arg0`.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D99464

Added: 
    

Modified: 
    mlir/lib/Dialect/StandardOps/IR/Ops.cpp
    mlir/test/Transforms/canonicalize.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
index 4b53bf47b6e5..3dad958887b5 100644
--- a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
+++ b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
@@ -2183,7 +2183,9 @@ static LogicalResult verify(TruncateIOp op) {
 
 OpFoldResult TruncateIOp::fold(ArrayRef<Attribute> operands) {
   // trunci(zexti(a)) -> a
-  if (matchPattern(getOperand(), m_Op<ZeroExtendIOp>()))
+  // trunci(sexti(a)) -> a
+  if (matchPattern(getOperand(), m_Op<ZeroExtendIOp>()) ||
+      matchPattern(getOperand(), m_Op<SignExtendIOp>()))
     return getOperand().getDefiningOp()->getOperand(0);
 
   return nullptr;

diff  --git a/mlir/test/Transforms/canonicalize.mlir b/mlir/test/Transforms/canonicalize.mlir
index fdf6f880ffec..e1869ac58f52 100644
--- a/mlir/test/Transforms/canonicalize.mlir
+++ b/mlir/test/Transforms/canonicalize.mlir
@@ -1109,3 +1109,14 @@ func @do_not_fold_trunci_vector(%arg0: vector<4xi1>) -> vector<4xi2> attributes
   %1 = trunci %0 : vector<4xi8> to vector<4xi2>
   return %1 : vector<4xi2>
 }
+
+// -----
+
+// CHECK-LABEL: func @fold_trunci_sexti
+// CHECK-SAME:    (%[[ARG0:[0-9a-z]*]]: i1)
+func @fold_trunci_sexti(%arg0: i1) -> i1 attributes {} {
+  // CHECK-NEXT: return %[[ARG0]] : i1
+  %0 = sexti %arg0 : i1 to i8
+  %1 = trunci %0 : i8 to i1
+  return %1 : i1
+}