[Mlir-commits] [mlir] 3bde144 - Revert "[mlir][arith] Add expansion pattern for ext/trunc of bf16"
Benjamin Kramer
llvmlistbot at llvm.org
Tue Apr 4 06:59:31 PDT 2023
Author: Benjamin Kramer
Date: 2023-04-04T15:58:38+02:00
New Revision: 3bde144de32dc09a0b227f7afcff94f908ac6739
URL: https://github.com/llvm/llvm-project/commit/3bde144de32dc09a0b227f7afcff94f908ac6739
DIFF: https://github.com/llvm/llvm-project/commit/3bde144de32dc09a0b227f7afcff94f908ac6739.diff
LOG: Revert "[mlir][arith] Add expansion pattern for ext/trunc of bf16"
This reverts commit 5bff523793ee8c30c260cc77b23c61dcbb606486. The
bf16->f32 conversion is incorrect. This can't be on by default, if you
want this behavior make it a separate pass.
Added:
Modified:
mlir/include/mlir/Dialect/Arith/Transforms/Passes.h
mlir/lib/Dialect/Arith/Transforms/ExpandOps.cpp
mlir/test/Dialect/Arith/expand-ops.mlir
Removed:
################################################################################
diff --git a/mlir/include/mlir/Dialect/Arith/Transforms/Passes.h b/mlir/include/mlir/Dialect/Arith/Transforms/Passes.h
index 6d60f8aefd63c..257a62aa39f78 100644
--- a/mlir/include/mlir/Dialect/Arith/Transforms/Passes.h
+++ b/mlir/include/mlir/Dialect/Arith/Transforms/Passes.h
@@ -38,9 +38,6 @@ void populateArithWideIntEmulationPatterns(
/// Add patterns to expand Arith ceil/floor division ops.
void populateCeilFloorDivExpandOpsPatterns(RewritePatternSet &patterns);
-/// Add patterns to expand Arith bf16 patterns to lower level bitcasts/shifts.
-void populateExpandBFloat16Patterns(RewritePatternSet &patterns);
-
/// Add patterns to expand Arith ops.
void populateArithExpandOpsPatterns(RewritePatternSet &patterns);
diff --git a/mlir/lib/Dialect/Arith/Transforms/ExpandOps.cpp b/mlir/lib/Dialect/Arith/Transforms/ExpandOps.cpp
index 7a6246991cff3..8f34531937c5c 100644
--- a/mlir/lib/Dialect/Arith/Transforms/ExpandOps.cpp
+++ b/mlir/lib/Dialect/Arith/Transforms/ExpandOps.cpp
@@ -10,7 +10,6 @@
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Vector/IR/VectorOps.h"
-#include "mlir/IR/ImplicitLocOpBuilder.h"
#include "mlir/IR/TypeUtilities.h"
#include "mlir/Transforms/DialectConversion.h"
@@ -26,13 +25,15 @@ using namespace mlir;
/// Create an integer or index constant.
static Value createConst(Location loc, Type type, int value,
PatternRewriter &rewriter) {
- auto attr = rewriter.getIntegerAttr(getElementTypeOrSelf(type), value);
- if (auto shapedTy = dyn_cast<ShapedType>(type)) {
+
+ auto elTy = getElementTypeOrSelf(type);
+ auto constantAttr = rewriter.getIntegerAttr(elTy, value);
+
+ if (auto vecTy = llvm::dyn_cast<ShapedType>(type))
return rewriter.create<arith::ConstantOp>(
- loc, DenseElementsAttr::get(shapedTy, attr));
- }
+ loc, vecTy, DenseElementsAttr::get(vecTy, constantAttr));
- return rewriter.create<arith::ConstantOp>(loc, attr);
+ return rewriter.create<arith::ConstantOp>(loc, constantAttr);
}
namespace {
@@ -186,73 +187,6 @@ struct MaxMinFOpConverter : public OpRewritePattern<OpTy> {
}
};
-struct BFloat16ExtFOpConverter : public OpRewritePattern<arith::ExtFOp> {
- using OpRewritePattern::OpRewritePattern;
- LogicalResult matchAndRewrite(arith::ExtFOp op,
- PatternRewriter &rewriter) const final {
- ImplicitLocOpBuilder b(op.getLoc(), rewriter);
- auto operand = op.getOperand();
- Type operandTy = operand.getType();
- Type resultTy = op.getType();
- Type operandETy = getElementTypeOrSelf(operandTy);
- Type resultETy = getElementTypeOrSelf(resultTy);
-
- if (!operandETy.isBF16() || !resultETy.isF32()) {
- return rewriter.notifyMatchFailure(op, "not a ext of bf16 to f32.");
- }
-
- Type i16Ty = b.getI16Type();
- Type i32Ty = b.getI32Type();
- if (auto shapedTy = dyn_cast<ShapedType>(operandTy)) {
- i16Ty = shapedTy.clone(i16Ty);
- i32Ty = shapedTy.clone(i32Ty);
- }
-
- Value bitcast = b.create<arith::BitcastOp>(i16Ty, operand);
- Value exti = b.create<arith::ExtUIOp>(i32Ty, bitcast);
-
- Value c16 = createConst(op.getLoc(), i32Ty, 16, rewriter);
- Value shl = b.create<arith::ShLIOp>(exti, c16);
- Value result = b.create<arith::BitcastOp>(resultTy, shl);
-
- rewriter.replaceOp(op, result);
- return success();
- }
-};
-
-struct BFloat16TruncFOpConverter : public OpRewritePattern<arith::TruncFOp> {
- using OpRewritePattern::OpRewritePattern;
- LogicalResult matchAndRewrite(arith::TruncFOp op,
- PatternRewriter &rewriter) const final {
- ImplicitLocOpBuilder b(op.getLoc(), rewriter);
- auto operand = op.getOperand();
- Type operandTy = operand.getType();
- Type resultTy = op.getType();
- Type operandETy = getElementTypeOrSelf(operandTy);
- Type resultETy = getElementTypeOrSelf(resultTy);
-
- if (!operandETy.isF32() || !resultETy.isBF16()) {
- return rewriter.notifyMatchFailure(op, "not a trunc of f32 to bf16.");
- }
-
- Type i16Ty = b.getI16Type();
- Type i32Ty = b.getI32Type();
- if (auto shapedTy = dyn_cast<ShapedType>(operandTy)) {
- i16Ty = shapedTy.clone(i16Ty);
- i32Ty = shapedTy.clone(i32Ty);
- }
-
- Value bitcast = b.create<arith::BitcastOp>(i32Ty, operand);
- Value c16 = createConst(op.getLoc(), i32Ty, 16, rewriter);
- Value shl = b.create<arith::ShRUIOp>(bitcast, c16);
- Value trunc = b.create<arith::TruncIOp>(i16Ty, shl);
- Value result = b.create<arith::BitcastOp>(resultTy, trunc);
-
- rewriter.replaceOp(op, result);
- return success();
- }
-};
-
struct ArithExpandOpsPass
: public arith::impl::ArithExpandOpsBase<ArithExpandOpsPass> {
void runOnOperation() override {
@@ -270,21 +204,6 @@ struct ArithExpandOpsPass
arith::MaxFOp,
arith::MinFOp
>();
-
- target.addDynamicallyLegalOp<arith::ExtFOp>(
- [](arith::ExtFOp op) {
- Type inETy = getElementTypeOrSelf(op.getOperand().getType());
- Type outETy = getElementTypeOrSelf(op.getType());
- return !(inETy.isBF16() && outETy.isF32());
- });
-
- target.addDynamicallyLegalOp<arith::TruncFOp>(
- [](arith::TruncFOp op) {
- Type inETy = getElementTypeOrSelf(op.getOperand().getType());
- Type outETy = getElementTypeOrSelf(op.getType());
- return !(inETy.isF32() && outETy.isBF16());
- });
-
// clang-format on
if (failed(applyPartialConversion(getOperation(), target,
std::move(patterns))))
@@ -301,19 +220,12 @@ void mlir::arith::populateCeilFloorDivExpandOpsPatterns(
patterns.getContext());
}
-void mlir::arith::populateExpandBFloat16Patterns(RewritePatternSet &patterns) {
- patterns.add<BFloat16ExtFOpConverter, BFloat16TruncFOpConverter>(
- patterns.getContext());
-}
-
void mlir::arith::populateArithExpandOpsPatterns(RewritePatternSet &patterns) {
populateCeilFloorDivExpandOpsPatterns(patterns);
// clang-format off
patterns.add<
MaxMinFOpConverter<MaxFOp, arith::CmpFPredicate::UGT>,
- MaxMinFOpConverter<MinFOp, arith::CmpFPredicate::ULT>,
- BFloat16ExtFOpConverter,
- BFloat16TruncFOpConverter
+ MaxMinFOpConverter<MinFOp, arith::CmpFPredicate::ULT>
>(patterns.getContext());
// clang-format on
}
diff --git a/mlir/test/Dialect/Arith/expand-ops.mlir b/mlir/test/Dialect/Arith/expand-ops.mlir
index ba87e2907abb1..7b7eb4003956a 100644
--- a/mlir/test/Dialect/Arith/expand-ops.mlir
+++ b/mlir/test/Dialect/Arith/expand-ops.mlir
@@ -215,67 +215,3 @@ func.func @minf(%a: f32, %b: f32) -> f32 {
// CHECK-NEXT: %[[IS_NAN:.*]] = arith.cmpf uno, %[[RHS]], %[[RHS]] : f32
// CHECK-NEXT: %[[RESULT:.*]] = arith.select %[[IS_NAN]], %[[RHS]], %[[SELECT]] : f32
// CHECK-NEXT: return %[[RESULT]] : f32
-
-// -----
-
-func.func @extf_bf16(%arg0 : bf16) -> f32 {
- %0 = arith.extf %arg0 : bf16 to f32
- return %0 : f32
-}
-
-// CHECK-LABEL: @extf_bf16
-// CHECK-SAME: %[[ARG0:.+]]: bf16
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[ARG0]] : bf16 to i16
-// CHECK-DAG: %[[EXT:.+]] = arith.extui %[[BITCAST]] : i16 to i32
-// CHECK-DAG: %[[C16:.+]] = arith.constant 16
-// CHECK-DAG: %[[SHLI:.+]] = arith.shli %[[EXT]], %[[C16]]
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[SHLI]] : i32 to f32
-// CHECK: return %[[BITCAST]]
-
-// -----
-
-func.func @extf_vector_bf16(%arg0 : vector<4xbf16>) -> vector<4xf32> {
- %0 = arith.extf %arg0 : vector<4xbf16> to vector<4xf32>
- return %0 : vector<4xf32>
-}
-
-// CHECK-LABEL: @extf_vector_bf16
-// CHECK-SAME: %[[ARG0:.+]]: vector<4xbf16>
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[ARG0]] : vector<4xbf16> to vector<4xi16>
-// CHECK-DAG: %[[EXT:.+]] = arith.extui %[[BITCAST]] : vector<4xi16> to vector<4xi32>
-// CHECK-DAG: %[[C16:.+]] = arith.constant dense<16>
-// CHECK-DAG: %[[SHLI:.+]] = arith.shli %[[EXT]], %[[C16]]
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[SHLI]] : vector<4xi32> to vector<4xf32>
-// CHECK: return %[[BITCAST]]
-
-// -----
-
-func.func @truncf_f32(%arg0 : f32) -> bf16 {
- %0 = arith.truncf %arg0 : f32 to bf16
- return %0 : bf16
-}
-
-// CHECK-LABEL: @truncf_f32
-// CHECK-SAME: %[[ARG0:.+]]: f32
-// CHECK-DAG: %[[C16:.+]] = arith.constant 16
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[ARG0]] : f32 to i32
-// CHECK-DAG: %[[SHR:.+]] = arith.shrui %[[BITCAST]], %[[C16]]
-// CHECK-DAG: %[[TRUNC:.+]] = arith.trunci %[[SHR]] : i32 to i16
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[TRUNC]] : i16 to bf16
-// CHECK: return %[[BITCAST]] : bf16
-
-// -----
-
-func.func @truncf_vector_f32(%arg0 : vector<4xf32>) -> vector<4xbf16> {
- %0 = arith.truncf %arg0 : vector<4xf32> to vector<4xbf16>
- return %0 : vector<4xbf16>
-}
-
-// CHECK-LABEL: @truncf_vector_f32
-// CHECK-SAME: %[[ARG0:.+]]: vector<4xf32>
-// CHECK-DAG: %[[C16:.+]] = arith.constant dense<16>
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[ARG0]] : vector<4xf32> to vector<4xi32>
-// CHECK-DAG: %[[SHR:.+]] = arith.shrui %[[BITCAST]], %[[C16]]
-// CHECK-DAG: %[[TRUNC:.+]] = arith.trunci %[[SHR]] : vector<4xi32> to vector<4xi16>
-// CHECK-DAG: %[[BITCAST:.+]] = arith.bitcast %[[TRUNC]] : vector<4xi16> to vector<4xbf16>
-// CHECK: return %[[BITCAST]] : vector<4xbf16>
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