[Mlir-commits] [mlir] Update MLIR to support nusw and nuw in GEP. (PR #137272)
Peiyong Lin
llvmlistbot at llvm.org
Mon Apr 28 11:51:33 PDT 2025
https://github.com/lpy updated https://github.com/llvm/llvm-project/pull/137272
>From 8a79d1bbaa065751aabf4494587e7aecfdfb2cb8 Mon Sep 17 00:00:00 2001
From: "Lin, Peiyong" <linpyong at gmail.com>
Date: Mon, 21 Apr 2025 21:09:23 +0000
Subject: [PATCH] Update MLIR to support nusw and nuw in GEP.
nusw and nuw were introduced in getelementptr, this patch plumbs them in MLIR.
Since inbounds implies nusw, this patch also adds an inboundsFlag to
represent the concept of raw inbounds with no nusw implication, and have
the inbounds literal captured as the combination of inboundsFlag and
nusw.
Fixes: iree#20482
Signed-off-by: Lin, Peiyong <linpyong at gmail.com>
---
mlir/include/mlir/Dialect/LLVMIR/LLVMEnums.td | 28 +++++++++++++++++++
mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td | 21 ++++++++++----
mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp | 23 ++++++++-------
mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp | 2 +-
mlir/lib/Target/LLVMIR/ModuleImport.cpp | 5 ++--
mlir/test/Dialect/LLVMIR/roundtrip.mlir | 8 ++++++
.../test/Target/LLVMIR/Import/instructions.ll | 19 +++++++++++++
mlir/test/Target/LLVMIR/llvmir.mlir | 8 ++++++
8 files changed, 95 insertions(+), 19 deletions(-)
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMEnums.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMEnums.td
index 45ccf30644920..6c0fe363d5551 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMEnums.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMEnums.td
@@ -876,4 +876,32 @@ def UWTableKindEnum : LLVM_EnumAttr<
let cppNamespace = "::mlir::LLVM::uwtable";
}
+//===----------------------------------------------------------------------===//
+// GEPNoWrapFlags
+//===----------------------------------------------------------------------===//
+
+// These values must match llvm::GEPNoWrapFlags ones.
+// See llvm/include/llvm/IR/GEPNoWrapFlags.h.
+// Since inbounds implies nusw, create an inboundsFlag that represents the
+// concept of raw inbounds with no nusw implication and the actual inbounds
+// literal will be captured as the combination of inboundsFlag and nusw.
+
+def GEPNone : I32BitEnumCaseNone<"none">;
+def GEPInboundsFlag : I32BitEnumCaseBit<"inboundsFlag", 0, "inbounds_flag">;
+def GEPNusw : I32BitEnumCaseBit<"nusw", 1>;
+def GEPNuw : I32BitEnumCaseBit<"nuw", 2>;
+def GEPInbounds : BitEnumCaseGroup<"inbounds", [GEPInboundsFlag, GEPNusw]>;
+
+def GEPNoWrapFlags : I32BitEnum<
+ "GEPNoWrapFlags",
+ "::mlir::LLVM::GEPNoWrapFlags",
+ [GEPNone, GEPInboundsFlag, GEPNusw, GEPNuw, GEPInbounds]> {
+ let cppNamespace = "::mlir::LLVM";
+ let printBitEnumPrimaryGroups = 1;
+}
+
+def GEPNoWrapFlagsProp : EnumProp<GEPNoWrapFlags> {
+ let defaultValue = interfaceType # "::none";
+}
+
#endif // LLVMIR_ENUMS
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
index 5745d370f7268..5315e3994b33d 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -291,7 +291,7 @@ def LLVM_GEPOp : LLVM_Op<"getelementptr", [Pure,
Variadic<LLVM_ScalarOrVectorOf<AnySignlessInteger>>:$dynamicIndices,
DenseI32ArrayAttr:$rawConstantIndices,
TypeAttr:$elem_type,
- UnitAttr:$inbounds);
+ GEPNoWrapFlagsProp:$noWrapFlags);
let results = (outs LLVM_ScalarOrVectorOf<LLVM_AnyPointer>:$res);
let skipDefaultBuilders = 1;
@@ -303,8 +303,12 @@ def LLVM_GEPOp : LLVM_Op<"getelementptr", [Pure,
as indices. In the case of indexing within a structure, it is required to
either use constant indices directly, or supply a constant SSA value.
- An optional 'inbounds' attribute specifies the low-level pointer arithmetic
+ The no-wrap flags can be used to specify the low-level pointer arithmetic
overflow behavior that LLVM uses after lowering the operation to LLVM IR.
+ Valid options include 'inbounds' (pointer arithmetic must be within object
+ bounds), 'nusw' (no unsigned signed wrap), and 'nuw' (no unsigned wrap).
+ Note that 'inbounds' implies 'nusw' which is ensured by the enum
+ definition. The flags can be set individually or in combination.
Examples:
@@ -323,10 +327,12 @@ def LLVM_GEPOp : LLVM_Op<"getelementptr", [Pure,
let builders = [
OpBuilder<(ins "Type":$resultType, "Type":$elementType, "Value":$basePtr,
- "ValueRange":$indices, CArg<"bool", "false">:$inbounds,
+ "ValueRange":$indices,
+ CArg<"GEPNoWrapFlags", "GEPNoWrapFlags::none">:$noWrapFlags,
CArg<"ArrayRef<NamedAttribute>", "{}">:$attributes)>,
OpBuilder<(ins "Type":$resultType, "Type":$elementType, "Value":$basePtr,
- "ArrayRef<GEPArg>":$indices, CArg<"bool", "false">:$inbounds,
+ "ArrayRef<GEPArg>":$indices,
+ CArg<"GEPNoWrapFlags", "GEPNoWrapFlags::none">:$noWrapFlags,
CArg<"ArrayRef<NamedAttribute>", "{}">:$attributes)>,
];
let llvmBuilder = [{
@@ -343,10 +349,13 @@ def LLVM_GEPOp : LLVM_Op<"getelementptr", [Pure,
}
Type baseElementType = op.getElemType();
llvm::Type *elementType = moduleTranslation.convertType(baseElementType);
- $res = builder.CreateGEP(elementType, $base, indices, "", $inbounds);
+ $res = builder.CreateGEP(elementType, $base, indices, "",
+ llvm::GEPNoWrapFlags::fromRaw(
+ static_cast<unsigned>(
+ op.getNoWrapFlags())));
}];
let assemblyFormat = [{
- (`inbounds` $inbounds^)?
+ ($noWrapFlags^)?
$base `[` custom<GEPIndices>($dynamicIndices, $rawConstantIndices) `]` attr-dict
`:` functional-type(operands, results) `,` $elem_type
}];
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
index 26c3ef1e8b8bf..c978e65c3c5fa 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -673,29 +673,29 @@ static void destructureIndices(Type currType, ArrayRef<GEPArg> indices,
void GEPOp::build(OpBuilder &builder, OperationState &result, Type resultType,
Type elementType, Value basePtr, ArrayRef<GEPArg> indices,
- bool inbounds, ArrayRef<NamedAttribute> attributes) {
+ GEPNoWrapFlags noWrapFlags,
+ ArrayRef<NamedAttribute> attributes) {
SmallVector<int32_t> rawConstantIndices;
SmallVector<Value> dynamicIndices;
destructureIndices(elementType, indices, rawConstantIndices, dynamicIndices);
result.addTypes(resultType);
result.addAttributes(attributes);
- result.addAttribute(getRawConstantIndicesAttrName(result.name),
- builder.getDenseI32ArrayAttr(rawConstantIndices));
- if (inbounds) {
- result.addAttribute(getInboundsAttrName(result.name),
- builder.getUnitAttr());
- }
- result.addAttribute(kElemTypeAttrName, TypeAttr::get(elementType));
+ result.getOrAddProperties<Properties>().rawConstantIndices =
+ builder.getDenseI32ArrayAttr(rawConstantIndices);
+ result.getOrAddProperties<Properties>().noWrapFlags = noWrapFlags;
+ result.getOrAddProperties<Properties>().elem_type =
+ TypeAttr::get(elementType);
result.addOperands(basePtr);
result.addOperands(dynamicIndices);
}
void GEPOp::build(OpBuilder &builder, OperationState &result, Type resultType,
Type elementType, Value basePtr, ValueRange indices,
- bool inbounds, ArrayRef<NamedAttribute> attributes) {
+ GEPNoWrapFlags noWrapFlags,
+ ArrayRef<NamedAttribute> attributes) {
build(builder, result, resultType, elementType, basePtr,
- SmallVector<GEPArg>(indices), inbounds, attributes);
+ SmallVector<GEPArg>(indices), noWrapFlags, attributes);
}
static ParseResult
@@ -794,6 +794,9 @@ LogicalResult LLVM::GEPOp::verify() {
return emitOpError("expected as many dynamic indices as specified in '")
<< getRawConstantIndicesAttrName().getValue() << "'";
+ if (getNoWrapFlags() == GEPNoWrapFlags::inboundsFlag)
+ return emitOpError("'inbounds_flag' can not be used directly.");
+
return verifyStructIndices(getElemType(), getIndices(),
[&] { return emitOpError(); });
}
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp
index 8640ef28a9e56..bc451f8b028fc 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMMemorySlot.cpp
@@ -891,7 +891,7 @@ DeletionKind LLVM::GEPOp::rewire(const DestructurableMemorySlot &slot,
auto byteType = IntegerType::get(builder.getContext(), 8);
auto newPtr = builder.createOrFold<LLVM::GEPOp>(
getLoc(), getResult().getType(), byteType, newSlot.ptr,
- ArrayRef<GEPArg>(accessInfo->subslotOffset), getInbounds());
+ ArrayRef<GEPArg>(accessInfo->subslotOffset), getNoWrapFlags());
getResult().replaceAllUsesWith(newPtr);
return DeletionKind::Delete;
}
diff --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index 3f80002c15ebb..c350addeeb8bc 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -1984,8 +1984,9 @@ LogicalResult ModuleImport::convertInstruction(llvm::Instruction *inst) {
}
Type type = convertType(inst->getType());
- auto gepOp = builder.create<GEPOp>(loc, type, sourceElementType, *basePtr,
- indices, gepInst->isInBounds());
+ auto gepOp = builder.create<GEPOp>(
+ loc, type, sourceElementType, *basePtr, indices,
+ static_cast<GEPNoWrapFlags>(gepInst->getNoWrapFlags().getRaw()));
mapValue(inst, gepOp);
return success();
}
diff --git a/mlir/test/Dialect/LLVMIR/roundtrip.mlir b/mlir/test/Dialect/LLVMIR/roundtrip.mlir
index 93916f621630d..e64e50fb86da5 100644
--- a/mlir/test/Dialect/LLVMIR/roundtrip.mlir
+++ b/mlir/test/Dialect/LLVMIR/roundtrip.mlir
@@ -236,6 +236,14 @@ llvm.func @gep(%ptr: !llvm.ptr, %idx: i64, %ptr2: !llvm.ptr) {
llvm.getelementptr %ptr[%idx, 1, 0] : (!llvm.ptr, i64) -> !llvm.ptr, !llvm.struct<(i32, struct<(i32, f32)>)>
// CHECK: llvm.getelementptr inbounds %{{.*}}[%{{.*}}, 0, %{{.*}}] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
llvm.getelementptr inbounds %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: llvm.getelementptr inbounds|nuw %{{.*}}[%{{.*}}, 0, %{{.*}}] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ llvm.getelementptr inbounds | nuw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: llvm.getelementptr nusw %{{.*}}[%{{.*}}, 0, %{{.*}}] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ llvm.getelementptr nusw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: llvm.getelementptr nusw|nuw %{{.*}}[%{{.*}}, 0, %{{.*}}] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ llvm.getelementptr nusw | nuw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: llvm.getelementptr nuw %{{.*}}[%{{.*}}, 0, %{{.*}}] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ llvm.getelementptr nuw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
llvm.return
}
diff --git a/mlir/test/Target/LLVMIR/Import/instructions.ll b/mlir/test/Target/LLVMIR/Import/instructions.ll
index c294e1b34f9bb..2098d85c18c3f 100644
--- a/mlir/test/Target/LLVMIR/Import/instructions.ll
+++ b/mlir/test/Target/LLVMIR/Import/instructions.ll
@@ -557,6 +557,25 @@ define void @gep_static_idx(ptr %ptr) {
; // -----
+; CHECK-LABEL: @gep_no_wrap_flags
+; CHECK-SAME: %[[PTR:[a-zA-Z0-9]+]]
+define void @gep_no_wrap_flags(ptr %ptr) {
+ ; CHECK: %[[IDX:.+]] = llvm.mlir.constant(7 : i32)
+ ; CHECK: llvm.getelementptr inbounds %[[PTR]][%[[IDX]]] : (!llvm.ptr, i32) -> !llvm.ptr, f32
+ %1 = getelementptr inbounds float, ptr %ptr, i32 7
+ ; CHECK: llvm.getelementptr nusw %[[PTR]][%[[IDX]]] : (!llvm.ptr, i32) -> !llvm.ptr, f32
+ %2 = getelementptr nusw float, ptr %ptr, i32 7
+ ; CHECK: llvm.getelementptr nuw %[[PTR]][%[[IDX]]] : (!llvm.ptr, i32) -> !llvm.ptr, f32
+ %3 = getelementptr nuw float, ptr %ptr, i32 7
+ ; CHECK: llvm.getelementptr nusw|nuw %[[PTR]][%[[IDX]]] : (!llvm.ptr, i32) -> !llvm.ptr, f32
+ %4 = getelementptr nusw nuw float, ptr %ptr, i32 7
+ ; CHECK: llvm.getelementptr inbounds|nuw %[[PTR]][%[[IDX]]] : (!llvm.ptr, i32) -> !llvm.ptr, f32
+ %5 = getelementptr inbounds nuw float, ptr %ptr, i32 7
+ ret void
+}
+
+; // -----
+
; CHECK: @varargs(...)
declare void @varargs(...)
diff --git a/mlir/test/Target/LLVMIR/llvmir.mlir b/mlir/test/Target/LLVMIR/llvmir.mlir
index 74fa327809864..4a2447263ae68 100644
--- a/mlir/test/Target/LLVMIR/llvmir.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir.mlir
@@ -1057,6 +1057,14 @@ llvm.func @gep(%ptr: !llvm.ptr, %idx: i64,
llvm.getelementptr %ptr[%idx, 1, 0] : (!llvm.ptr, i64) -> !llvm.ptr, !llvm.struct<(i32, struct<(i32, f32)>)>
// CHECK: = getelementptr inbounds { [10 x float] }, ptr %{{.*}}, i64 %{{.*}}, i32 0, i64 %{{.*}}
llvm.getelementptr inbounds %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: = getelementptr inbounds nuw { [10 x float] }, ptr %{{.*}}, i64 %{{.*}}, i32 0, i64 %{{.*}}
+ llvm.getelementptr inbounds | nuw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: = getelementptr nusw { [10 x float] }, ptr %{{.*}}, i64 %{{.*}}, i32 0, i64 %{{.*}}
+ llvm.getelementptr nusw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: = getelementptr nusw nuw { [10 x float] }, ptr %{{.*}}, i64 %{{.*}}, i32 0, i64 %{{.*}}
+ llvm.getelementptr nusw | nuw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
+ // CHECK: = getelementptr nuw { [10 x float] }, ptr %{{.*}}, i64 %{{.*}}, i32 0, i64 %{{.*}}
+ llvm.getelementptr nuw %ptr2[%idx, 0, %idx] : (!llvm.ptr, i64, i64) -> !llvm.ptr, !llvm.struct<(array<10 x f32>)>
llvm.return
}
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