[Mlir-commits] [mlir] 6668d14 - [mlir][arith] Canonicalization patterns for `arith.select` (#67809)

llvmlistbot at llvm.org llvmlistbot at llvm.org
Mon Oct 9 11:08:09 PDT 2023


Author: peterbell10
Date: 2023-10-09T11:08:05-07:00
New Revision: 6668d14931c31d3dd80580930b4154e1eb1721b2

URL: https://github.com/llvm/llvm-project/commit/6668d14931c31d3dd80580930b4154e1eb1721b2
DIFF: https://github.com/llvm/llvm-project/commit/6668d14931c31d3dd80580930b4154e1eb1721b2.diff

LOG: [mlir][arith] Canonicalization patterns for `arith.select` (#67809)

This adds the following canonicalization patterns:
- Inverting condition:
  - `select(not(pred), a, b) => select(pred, b, a)`
- Merging consecutive selects with the same predicate
  - `select(pred, select(pred, a, b), c) => select(pred, a, c)`
  - `select(pred, a, select(pred, b, c)) => select(pred, a, c)`
- Merging consecutive selects with a common value:
- `select(predA, select(predB, a, b), b) => select(and(predA, predB), a,
b)`
- `select(predA, select(predB, b, a), b) => select(and(predA,
not(predB)), a, b)`
- `select(predA, a, select(predB, a, b)) => select(or(predA, predB), a,
b)`
- `select(predA, a, select(predB, b, a)) => select(or(predA,
not(predB)), a, b)`

Added: 
    

Modified: 
    mlir/lib/Dialect/Arith/IR/ArithCanonicalization.td
    mlir/lib/Dialect/Arith/IR/ArithOps.cpp
    mlir/test/Dialect/Arith/canonicalize.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Dialect/Arith/IR/ArithCanonicalization.td b/mlir/lib/Dialect/Arith/IR/ArithCanonicalization.td
index f3d84d0b261e8dd..9d38513215d3e3d 100644
--- a/mlir/lib/Dialect/Arith/IR/ArithCanonicalization.td
+++ b/mlir/lib/Dialect/Arith/IR/ArithCanonicalization.td
@@ -233,6 +233,50 @@ def CmpIExtUI :
             CPred<"$0.getValue() == arith::CmpIPredicate::eq || "
                   "$0.getValue() == arith::CmpIPredicate::ne">> $pred)]>;
 
+//===----------------------------------------------------------------------===//
+// SelectOp
+//===----------------------------------------------------------------------===//
+
+// select(not(pred), a, b) => select(pred, b, a)
+def SelectNotCond :
+    Pat<(SelectOp (Arith_XOrIOp $pred, (ConstantLikeMatcher APIntAttr:$ones)), $a, $b),
+        (SelectOp $pred, $b, $a),
+        [(IsScalarOrSplatNegativeOne $ones)]>;
+
+// select(pred, select(pred, a, b), c) => select(pred, a, c)
+def RedundantSelectTrue :
+    Pat<(SelectOp $pred, (SelectOp $pred, $a, $b), $c),
+        (SelectOp $pred, $a, $c)>;
+
+// select(pred, a, select(pred, b, c)) => select(pred, a, c)
+def RedundantSelectFalse :
+    Pat<(SelectOp $pred, $a, (SelectOp $pred, $b, $c)),
+        (SelectOp $pred, $a, $c)>;
+
+// select(predA, select(predB, x, y), y) => select(and(predA, predB), x, y)
+def SelectAndCond :
+    Pat<(SelectOp $predA, (SelectOp $predB, $x, $y), $y),
+        (SelectOp (Arith_AndIOp $predA, $predB), $x, $y)>;
+
+// select(predA, select(predB, y, x), y) => select(and(predA, not(predB)), x, y)
+def SelectAndNotCond :
+    Pat<(SelectOp $predA, (SelectOp $predB, $y, $x), $y),
+        (SelectOp (Arith_AndIOp $predA,
+                                (Arith_XOrIOp $predB, (Arith_ConstantOp ConstantAttr<I1Attr, "1">))),
+                  $x, $y)>;
+
+// select(predA, x, select(predB, x, y)) => select(or(predA, predB), x, y)
+def SelectOrCond :
+    Pat<(SelectOp $predA, $x, (SelectOp $predB, $x, $y)),
+        (SelectOp (Arith_OrIOp $predA, $predB), $x, $y)>;
+
+// select(predA, x, select(predB, y, x)) => select(or(predA, not(predB)), x, y)
+def SelectOrNotCond :
+    Pat<(SelectOp $predA, $x, (SelectOp $predB, $y, $x)),
+        (SelectOp (Arith_OrIOp $predA,
+                               (Arith_XOrIOp $predB, (Arith_ConstantOp ConstantAttr<I1Attr, "1">))),
+                  $x, $y)>;
+
 //===----------------------------------------------------------------------===//
 // IndexCastOp
 //===----------------------------------------------------------------------===//

diff  --git a/mlir/lib/Dialect/Arith/IR/ArithOps.cpp b/mlir/lib/Dialect/Arith/IR/ArithOps.cpp
index ae8a6ef350ce191..0ecc288f3b07701 100644
--- a/mlir/lib/Dialect/Arith/IR/ArithOps.cpp
+++ b/mlir/lib/Dialect/Arith/IR/ArithOps.cpp
@@ -2212,7 +2212,9 @@ struct SelectToExtUI : public OpRewritePattern<arith::SelectOp> {
 
 void arith::SelectOp::getCanonicalizationPatterns(RewritePatternSet &results,
                                                   MLIRContext *context) {
-  results.add<SelectI1Simplify, SelectToExtUI>(context);
+  results.add<RedundantSelectFalse, RedundantSelectTrue, SelectI1Simplify,
+              SelectAndCond, SelectAndNotCond, SelectOrCond, SelectOrNotCond,
+              SelectNotCond, SelectToExtUI>(context);
 }
 
 OpFoldResult arith::SelectOp::fold(FoldAdaptor adaptor) {

diff  --git a/mlir/test/Dialect/Arith/canonicalize.mlir b/mlir/test/Dialect/Arith/canonicalize.mlir
index f697f3d01458eee..1b0547c9e8f804a 100644
--- a/mlir/test/Dialect/Arith/canonicalize.mlir
+++ b/mlir/test/Dialect/Arith/canonicalize.mlir
@@ -128,6 +128,82 @@ func.func @selToArith(%arg0: i1, %arg1 : i1, %arg2 : i1) -> i1 {
   return %res : i1
 }
 
+// CHECK-LABEL: @redundantSelectTrue
+//       CHECK-NEXT: %[[res:.+]] = arith.select %arg0, %arg1, %arg3
+//       CHECK-NEXT: return %[[res]]
+func.func @redundantSelectTrue(%arg0: i1, %arg1 : i32, %arg2 : i32, %arg3 : i32) -> i32 {
+  %0 = arith.select %arg0, %arg1, %arg2 : i32
+  %res = arith.select %arg0, %0, %arg3 : i32
+  return %res : i32
+}
+
+// CHECK-LABEL: @redundantSelectFalse
+//       CHECK-NEXT: %[[res:.+]] = arith.select %arg0, %arg3, %arg2
+//       CHECK-NEXT: return %[[res]]
+func.func @redundantSelectFalse(%arg0: i1, %arg1 : i32, %arg2 : i32, %arg3 : i32) -> i32 {
+  %0 = arith.select %arg0, %arg1, %arg2 : i32
+  %res = arith.select %arg0, %arg3, %0 : i32
+  return %res : i32
+}
+
+// CHECK-LABEL: @selNotCond
+//       CHECK-NEXT: %[[res1:.+]] = arith.select %arg0, %arg2, %arg1
+//       CHECK-NEXT: %[[res2:.+]] = arith.select %arg0, %arg4, %arg3
+//       CHECK-NEXT: return %[[res1]], %[[res2]]
+func.func @selNotCond(%arg0: i1, %arg1 : i32, %arg2 : i32, %arg3 : i32, %arg4 : i32) -> (i32, i32) {
+  %one = arith.constant 1 : i1
+  %cond1 = arith.xori %arg0, %one : i1
+  %cond2 = arith.xori %one, %arg0 : i1
+
+  %res1 = arith.select %cond1, %arg1, %arg2 : i32
+  %res2 = arith.select %cond2, %arg3, %arg4 : i32
+  return %res1, %res2 : i32, i32
+}
+
+// CHECK-LABEL: @selAndCond
+//       CHECK-NEXT: %[[and:.+]] = arith.andi %arg1, %arg0
+//       CHECK-NEXT: %[[res:.+]] = arith.select %[[and]], %arg2, %arg3
+//       CHECK-NEXT: return %[[res]]
+func.func @selAndCond(%arg0: i1, %arg1: i1, %arg2 : i32, %arg3 : i32) -> i32 {
+  %sel = arith.select %arg0, %arg2, %arg3 : i32
+  %res = arith.select %arg1, %sel, %arg3 : i32
+  return %res : i32
+}
+
+// CHECK-LABEL: @selAndNotCond
+//       CHECK-NEXT: %[[one:.+]] = arith.constant true
+//       CHECK-NEXT: %[[not:.+]] = arith.xori %arg0, %[[one]]
+//       CHECK-NEXT: %[[and:.+]] = arith.andi %arg1, %[[not]]
+//       CHECK-NEXT: %[[res:.+]] = arith.select %[[and]], %arg3, %arg2
+//       CHECK-NEXT: return %[[res]]
+func.func @selAndNotCond(%arg0: i1, %arg1: i1, %arg2 : i32, %arg3 : i32) -> i32 {
+  %sel = arith.select %arg0, %arg2, %arg3 : i32
+  %res = arith.select %arg1, %sel, %arg2 : i32
+  return %res : i32
+}
+
+// CHECK-LABEL: @selOrCond
+//       CHECK-NEXT: %[[or:.+]] = arith.ori %arg1, %arg0
+//       CHECK-NEXT: %[[res:.+]] = arith.select %[[or]], %arg2, %arg3
+//       CHECK-NEXT: return %[[res]]
+func.func @selOrCond(%arg0: i1, %arg1: i1, %arg2 : i32, %arg3 : i32) -> i32 {
+  %sel = arith.select %arg0, %arg2, %arg3 : i32
+  %res = arith.select %arg1, %arg2, %sel : i32
+  return %res : i32
+}
+
+// CHECK-LABEL: @selOrNotCond
+//       CHECK-NEXT: %[[one:.+]] = arith.constant true
+//       CHECK-NEXT: %[[not:.+]] = arith.xori %arg0, %[[one]]
+//       CHECK-NEXT: %[[or:.+]] = arith.ori %arg1, %[[not]]
+//       CHECK-NEXT: %[[res:.+]] = arith.select %[[or]], %arg3, %arg2
+//       CHECK-NEXT: return %[[res]]
+func.func @selOrNotCond(%arg0: i1, %arg1: i1, %arg2 : i32, %arg3 : i32) -> i32 {
+  %sel = arith.select %arg0, %arg2, %arg3 : i32
+  %res = arith.select %arg1, %arg3, %sel : i32
+  return %res : i32
+}
+
 // Test case: Folding of comparisons with equal operands.
 // CHECK-LABEL: @cmpi_equal_operands
 //   CHECK-DAG:   %[[T:.*]] = arith.constant true


        


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