[Mlir-commits] [mlir] [mlir][vector]: Extend convertIntegerAttr to handle float-to-integer conversion (PR #159627)
Jhalak Patel
llvmlistbot at llvm.org
Tue Sep 23 10:56:47 PDT 2025
https://github.com/jhalakpatel updated https://github.com/llvm/llvm-project/pull/159627
>From e703711419ee093329873ff510fea76a245e9c0a Mon Sep 17 00:00:00 2001
From: Jhalak Patel <jhalakp at nvidia.com>
Date: Thu, 18 Sep 2025 12:03:26 -0700
Subject: [PATCH 1/3] [mlir][vector]: Rename VectorOps.cpp convertIntegerAttr
to convertNumericAttr and handle float attributes
---
mlir/lib/Dialect/Vector/IR/VectorOps.cpp | 65 +++++++++++++---------
mlir/test/Dialect/Vector/canonicalize.mlir | 22 ++++++++
2 files changed, 60 insertions(+), 27 deletions(-)
diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
index 347141e2773b8..859791f971bef 100644
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -396,14 +396,36 @@ std::optional<int64_t> vector::getConstantVscaleMultiplier(Value value) {
return {};
}
-/// Converts an IntegerAttr to have the specified type if needed.
-/// This handles cases where integer constant attributes have a different type
-/// than the target element type.
-static IntegerAttr convertIntegerAttr(IntegerAttr intAttr, Type expectedType) {
- if (intAttr.getType() == expectedType)
- return intAttr; // Already correct type
+/// Converts numeric attributes to the expected type. Supports
+/// integer-to-integer and float-to-integer conversions. Returns the original
+/// attribute if no conversion is needed or supported.
+static Attribute convertNumericAttr(Attribute attr, Type expectedType) {
+ // Integer-to-integer conversion
+ if (auto intAttr = dyn_cast<IntegerAttr>(attr)) {
+ if (auto intType = dyn_cast<IntegerType>(expectedType)) {
+ if (intAttr.getType() != expectedType)
+ return IntegerAttr::get(expectedType, intAttr.getInt());
+ }
+ return attr;
+ }
+
+ // Float-to-integer conversion
+ if (auto floatAttr = dyn_cast<FloatAttr>(attr)) {
+ auto intType = dyn_cast<IntegerType>(expectedType);
+ if (!intType)
+ return attr;
+
+ APFloat floatVal = floatAttr.getValue();
+ APSInt intVal(intType.getWidth(), intType.isUnsigned());
+ bool isExact = false;
+ [[maybe_unused]] APFloat::opStatus status =
+ floatVal.convertToInteger(intVal, APFloat::rmTowardZero, &isExact);
+ assert(status == APFloat::opOK && "float-to-integer conversion failed");
+ assert(isExact && "float-to-integer conversion must be exact");
+ return IntegerAttr::get(expectedType, intVal);
+ }
- return IntegerAttr::get(expectedType, intAttr.getInt());
+ return attr;
}
//===----------------------------------------------------------------------===//
@@ -2473,16 +2495,11 @@ static OpFoldResult foldFromElementsToConstant(FromElementsOp fromElementsOp,
if (!destEltType.isIntOrIndexOrFloat() && !isa<ComplexType>(destEltType))
return {};
- // Convert integer attributes to the target type if needed, leave others
- // unchanged.
- auto convertedElements =
- llvm::map_to_vector(elements, [&](Attribute attr) -> Attribute {
- if (auto intAttr = dyn_cast<IntegerAttr>(attr)) {
- return convertIntegerAttr(intAttr, destEltType);
- }
- return attr; // Non-integer attributes (FloatAttr, etc.) returned
- // unchanged
- });
+ // Constant attributes might have a different type than the return type.
+ // Convert them before creating the dense elements attribute.
+ auto convertedElements = llvm::map_to_vector(elements, [&](Attribute attr) {
+ return convertNumericAttr(attr, destEltType);
+ });
return DenseElementsAttr::get(destVecType, convertedElements);
}
@@ -3503,19 +3520,13 @@ foldDenseElementsAttrDestInsertOp(InsertOp insertOp, Attribute srcAttr,
SmallVector<Attribute> insertedValues;
Type destEltType = destTy.getElementType();
- /// Converts integer attributes to the expected type if there's a mismatch.
- /// Non-integer attributes are left unchanged.
+ /// Converts attribute to the expected type if there's
+ /// a mismatch.
if (auto denseSource = llvm::dyn_cast<DenseElementsAttr>(srcAttr)) {
for (auto value : denseSource.getValues<Attribute>())
- if (auto intAttr = dyn_cast<IntegerAttr>(value))
- insertedValues.push_back(convertIntegerAttr(intAttr, destEltType));
- else
- insertedValues.push_back(value); // Non-integer attributes unchanged
+ insertedValues.push_back(convertNumericAttr(value, destEltType));
} else {
- if (auto intAttr = dyn_cast<IntegerAttr>(srcAttr))
- insertedValues.push_back(convertIntegerAttr(intAttr, destEltType));
- else
- insertedValues.push_back(srcAttr); // Non-integer attributes unchanged
+ insertedValues.push_back(convertNumericAttr(srcAttr, destEltType));
}
auto allValues = llvm::to_vector(denseDst.getValues<Attribute>());
diff --git a/mlir/test/Dialect/Vector/canonicalize.mlir b/mlir/test/Dialect/Vector/canonicalize.mlir
index 75c762f38432a..f356943bb5faf 100644
--- a/mlir/test/Dialect/Vector/canonicalize.mlir
+++ b/mlir/test/Dialect/Vector/canonicalize.mlir
@@ -3411,6 +3411,28 @@ func.func @negative_from_elements_poison_constant_mix() -> vector<2xf32> {
return %1 : vector<2xf32>
}
+// -----
+
+// CHECK-LABEL: func @from_elements_float8_to_i8_conversion(
+// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<0> : vector<1xi8>
+// CHECK-NEXT: return %[[CST]] : vector<1xi8>
+func.func @from_elements_float8_to_i8_conversion() -> vector<1xi8> {
+ %cst = llvm.mlir.constant(0.0 : f8E4M3FN) : i8
+ %v = vector.from_elements %cst : vector<1xi8>
+ return %v : vector<1xi8>
+}
+
+// -----
+
+// CHECK-LABEL: func @from_elements_i1_to_i8_conversion(
+// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<0> : vector<1xi8>
+// CHECK-NEXT: return %[[CST]] : vector<1xi8>
+func.func @from_elements_i1_to_i8_conversion() -> vector<1xi8> {
+ %cst = llvm.mlir.constant(0: i1) : i8
+ %v = vector.from_elements %cst : vector<1xi8>
+ return %v : vector<1xi8>
+}
+
// +---------------------------------------------------------------------------
// End of Tests for foldFromElementsToConstant
// +---------------------------------------------------------------------------
>From 219a1d2ff86a6cc22ebb840d53f3a637901d3770 Mon Sep 17 00:00:00 2001
From: Jhalak Patel <jhalakp at nvidia.com>
Date: Mon, 22 Sep 2025 15:38:38 -0700
Subject: [PATCH 2/3] Update float conversion to use bitcast instead of
numerical conversion
---
mlir/lib/Dialect/Vector/IR/VectorOps.cpp | 9 ++-----
mlir/test/Dialect/Vector/canonicalize.mlir | 31 +++++++++++++++++-----
2 files changed, 27 insertions(+), 13 deletions(-)
diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
index 859791f971bef..926d97bf6e38f 100644
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -409,19 +409,14 @@ static Attribute convertNumericAttr(Attribute attr, Type expectedType) {
return attr;
}
- // Float-to-integer conversion
+ // Float-to-integer bitcast (preserves bit representation)
if (auto floatAttr = dyn_cast<FloatAttr>(attr)) {
auto intType = dyn_cast<IntegerType>(expectedType);
if (!intType)
return attr;
APFloat floatVal = floatAttr.getValue();
- APSInt intVal(intType.getWidth(), intType.isUnsigned());
- bool isExact = false;
- [[maybe_unused]] APFloat::opStatus status =
- floatVal.convertToInteger(intVal, APFloat::rmTowardZero, &isExact);
- assert(status == APFloat::opOK && "float-to-integer conversion failed");
- assert(isExact && "float-to-integer conversion must be exact");
+ APInt intVal = floatVal.bitcastToAPInt();
return IntegerAttr::get(expectedType, intVal);
}
diff --git a/mlir/test/Dialect/Vector/canonicalize.mlir b/mlir/test/Dialect/Vector/canonicalize.mlir
index f356943bb5faf..cfc57d6790e9b 100644
--- a/mlir/test/Dialect/Vector/canonicalize.mlir
+++ b/mlir/test/Dialect/Vector/canonicalize.mlir
@@ -3414,12 +3414,31 @@ func.func @negative_from_elements_poison_constant_mix() -> vector<2xf32> {
// -----
// CHECK-LABEL: func @from_elements_float8_to_i8_conversion(
-// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<0> : vector<1xi8>
-// CHECK-NEXT: return %[[CST]] : vector<1xi8>
-func.func @from_elements_float8_to_i8_conversion() -> vector<1xi8> {
- %cst = llvm.mlir.constant(0.0 : f8E4M3FN) : i8
- %v = vector.from_elements %cst : vector<1xi8>
- return %v : vector<1xi8>
+// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<[0, 56, -72, 69, 127, -1]> : vector<6xi8>
+// CHECK-NEXT: return %[[CST]] : vector<6xi8>
+func.func @from_elements_float8_to_i8_conversion() -> vector<6xi8> {
+ %cst0 = llvm.mlir.constant(0.0 : f8E4M3FN) : i8
+ %cst1 = llvm.mlir.constant(1.0 : f8E4M3FN) : i8
+ %cst_neg1 = llvm.mlir.constant(-1.0 : f8E4M3FN) : i8
+ %cst_pi = llvm.mlir.constant(3.14 : f8E4M3FN) : i8
+ %cst_inf = llvm.mlir.constant(0x7F : f8E4M3FN) : i8
+ %cst_neg_inf = llvm.mlir.constant(0xFF : f8E4M3FN) : i8
+ %v = vector.from_elements %cst0, %cst1, %cst_neg1, %cst_pi, %cst_inf, %cst_neg_inf : vector<6xi8>
+ return %v : vector<6xi8>
+}
+
+// CHECK-LABEL: func @from_elements_float16_to_i16_conversion(
+// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<[0, 15360, -17408, 16968, 31743, -1025]> : vector<6xi16>
+// CHECK-NEXT: return %[[CST]] : vector<6xi16>
+func.func @from_elements_float16_to_i16_conversion() -> vector<6xi16> {
+ %cst0 = llvm.mlir.constant(0.0 : f16) : i16
+ %cst1 = llvm.mlir.constant(1.0 : f16) : i16
+ %cst_neg1 = llvm.mlir.constant(-1.0 : f16) : i16
+ %cst_pi = llvm.mlir.constant(3.14 : f16) : i16
+ %cst_max = llvm.mlir.constant(65504.0 : f16) : i16
+ %cst_min = llvm.mlir.constant(-65504.0 : f16) : i16
+ %v = vector.from_elements %cst0, %cst1, %cst_neg1, %cst_pi, %cst_max, %cst_min : vector<6xi16>
+ return %v : vector<6xi16>
}
// -----
>From 7c6e6034b54802f67d6a668a6ca5ae0210949a62 Mon Sep 17 00:00:00 2001
From: Jhalak Patel <jhalakp at nvidia.com>
Date: Tue, 23 Sep 2025 10:56:25 -0700
Subject: [PATCH 3/3] Add index to i64 test
---
mlir/test/Dialect/Vector/canonicalize.mlir | 27 ++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/mlir/test/Dialect/Vector/canonicalize.mlir b/mlir/test/Dialect/Vector/canonicalize.mlir
index cfc57d6790e9b..5448976f84760 100644
--- a/mlir/test/Dialect/Vector/canonicalize.mlir
+++ b/mlir/test/Dialect/Vector/canonicalize.mlir
@@ -3441,6 +3441,20 @@ func.func @from_elements_float16_to_i16_conversion() -> vector<6xi16> {
return %v : vector<6xi16>
}
+// CHECK-LABEL: func @from_elements_f64_to_i64_conversion(
+// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<[0, 4607182418800017408, -4616189618054758400, 4614253070214989087, 9218868437227405311, -4503599627370497]> : vector<6xi64>
+// CHECK-NEXT: return %[[CST]] : vector<6xi64>
+func.func @from_elements_f64_to_i64_conversion() -> vector<6xi64> {
+ %cst0 = llvm.mlir.constant(0.0 : f64) : i64
+ %cst1 = llvm.mlir.constant(1.0 : f64) : i64
+ %cst_neg1 = llvm.mlir.constant(-1.0 : f64) : i64
+ %cst_pi = llvm.mlir.constant(3.14 : f64) : i64
+ %cst_max = llvm.mlir.constant(1.7976931348623157e+308 : f64) : i64
+ %cst_min = llvm.mlir.constant(-1.7976931348623157e+308 : f64) : i64
+ %v = vector.from_elements %cst0, %cst1, %cst_neg1, %cst_pi, %cst_max, %cst_min : vector<6xi64>
+ return %v : vector<6xi64>
+}
+
// -----
// CHECK-LABEL: func @from_elements_i1_to_i8_conversion(
@@ -3452,6 +3466,19 @@ func.func @from_elements_i1_to_i8_conversion() -> vector<1xi8> {
return %v : vector<1xi8>
}
+// -----
+
+// CHECK-LABEL: func @from_elements_index_to_i64_conversion(
+// CHECK-NEXT: %[[CST:.*]] = arith.constant dense<[0, 1, 42]> : vector<3xi64>
+// CHECK-NEXT: return %[[CST]] : vector<3xi64>
+func.func @from_elements_index_to_i64_conversion() -> vector<3xi64> {
+ %cst0 = llvm.mlir.constant(0 : index) : i64
+ %cst1 = llvm.mlir.constant(1 : index) : i64
+ %cst42 = llvm.mlir.constant(42 : index) : i64
+ %v = vector.from_elements %cst0, %cst1, %cst42 : vector<3xi64>
+ return %v : vector<3xi64>
+}
+
// +---------------------------------------------------------------------------
// End of Tests for foldFromElementsToConstant
// +---------------------------------------------------------------------------
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