[flang-commits] [flang] Reland "[flang][nfc] Support volatility in Fir ops" (PR #135039)
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flang-commits at lists.llvm.org
Wed Apr 9 08:25:09 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-fir-hlfir
Author: Asher Mancinelli (ashermancinelli)
<details>
<summary>Changes</summary>
#<!-- -->134858 had an extraneous include which caused the shared library builds to break.
---
Patch is 22.27 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/135039.diff
9 Files Affected:
- (modified) flang/include/flang/Optimizer/Builder/FIRBuilder.h (+5)
- (modified) flang/include/flang/Optimizer/Dialect/FIROps.h (+6)
- (modified) flang/include/flang/Optimizer/Dialect/FIROps.td (+31-12)
- (modified) flang/include/flang/Optimizer/Dialect/FIROpsSupport.h (+20-7)
- (modified) flang/lib/Lower/ConvertExprToHLFIR.cpp (+7-2)
- (modified) flang/lib/Optimizer/Builder/FIRBuilder.cpp (+15-3)
- (modified) flang/lib/Optimizer/Dialect/FIROps.cpp (+91-1)
- (modified) flang/test/Fir/cse.fir (+20)
- (modified) flang/test/Fir/invalid.fir (+54)
``````````diff
diff --git a/flang/include/flang/Optimizer/Builder/FIRBuilder.h b/flang/include/flang/Optimizer/Builder/FIRBuilder.h
index ddd4ef7114a63..8fca4272636b1 100644
--- a/flang/include/flang/Optimizer/Builder/FIRBuilder.h
+++ b/flang/include/flang/Optimizer/Builder/FIRBuilder.h
@@ -397,6 +397,11 @@ class FirOpBuilder : public mlir::OpBuilder, public mlir::OpBuilder::Listener {
mlir::Value createConvert(mlir::Location loc, mlir::Type toTy,
mlir::Value val);
+ /// Create a fir.convert op with a volatile cast if the source value's type
+ /// does not match the target type's volatility.
+ mlir::Value createConvertWithVolatileCast(mlir::Location loc, mlir::Type toTy,
+ mlir::Value val);
+
/// Create a fir.store of \p val into \p addr. A lazy conversion
/// of \p val to the element type of \p addr is created if needed.
void createStoreWithConvert(mlir::Location loc, mlir::Value val,
diff --git a/flang/include/flang/Optimizer/Dialect/FIROps.h b/flang/include/flang/Optimizer/Dialect/FIROps.h
index ed301016ad01c..f3dbf47351ab8 100644
--- a/flang/include/flang/Optimizer/Dialect/FIROps.h
+++ b/flang/include/flang/Optimizer/Dialect/FIROps.h
@@ -50,6 +50,12 @@ struct DebuggingResource
mlir::StringRef getName() final { return "DebuggingResource"; }
};
+/// Model operations which read from/write to volatile memory
+struct VolatileMemoryResource
+ : public mlir::SideEffects::Resource::Base<VolatileMemoryResource> {
+ mlir::StringRef getName() final { return "VolatileMemoryResource"; }
+};
+
class CoordinateIndicesAdaptor;
using IntOrValue = llvm::PointerUnion<mlir::IntegerAttr, mlir::Value>;
diff --git a/flang/include/flang/Optimizer/Dialect/FIROps.td b/flang/include/flang/Optimizer/Dialect/FIROps.td
index 753e4bd18dc6d..c7ac2c0397413 100644
--- a/flang/include/flang/Optimizer/Dialect/FIROps.td
+++ b/flang/include/flang/Optimizer/Dialect/FIROps.td
@@ -286,7 +286,8 @@ def fir_FreeMemOp : fir_Op<"freemem", [MemoryEffects<[MemFree]>]> {
let assemblyFormat = "$heapref attr-dict `:` qualified(type($heapref))";
}
-def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface]> {
+def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface,
+ DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
let summary = "load a value from a memory reference";
let description = [{
Load a value from a memory reference into an ssa-value (virtual register).
@@ -302,7 +303,7 @@ def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface]> {
or null.
}];
- let arguments = (ins Arg<AnyReferenceLike, "", [MemRead]>:$memref,
+ let arguments = (ins AnyReferenceLike:$memref,
OptionalAttr<LLVM_TBAATagArrayAttr>:$tbaa);
let builders = [OpBuilder<(ins "mlir::Value":$refVal)>,
@@ -315,7 +316,8 @@ def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface]> {
}];
}
-def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface]> {
+def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface,
+ DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
let summary = "store an SSA-value to a memory location";
let description = [{
@@ -335,7 +337,7 @@ def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface]> {
}];
let arguments = (ins AnyType:$value,
- Arg<AnyReferenceLike, "", [MemWrite]>:$memref,
+ AnyReferenceLike:$memref,
OptionalAttr<LLVM_TBAATagArrayAttr>:$tbaa);
let builders = [OpBuilder<(ins "mlir::Value":$value, "mlir::Value":$memref)>];
@@ -348,7 +350,7 @@ def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface]> {
}];
}
-def fir_CopyOp : fir_Op<"copy", []> {
+def fir_CopyOp : fir_Op<"copy", [DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
let summary = "copy constant size memory";
let description = [{
@@ -369,8 +371,8 @@ def fir_CopyOp : fir_Op<"copy", []> {
TODO: add FirAliasTagOpInterface to carry TBAA.
}];
- let arguments = (ins Arg<AnyRefOfConstantSizeAggregateType, "", [MemRead]>:$source,
- Arg<AnyRefOfConstantSizeAggregateType, "", [MemWrite]>:$destination,
+ let arguments = (ins AnyRefOfConstantSizeAggregateType:$source,
+ AnyRefOfConstantSizeAggregateType:$destination,
OptionalAttr<UnitAttr>:$no_overlap);
let builders = [OpBuilder<(ins "mlir::Value":$source,
@@ -1373,7 +1375,8 @@ def fir_BoxTypeDescOp : fir_SimpleOneResultOp<"box_tdesc", [NoMemoryEffect]> {
// !- Merge the new and old values into the memory for "A"
// array_merge_store <updated A> to <A's address>
-def fir_ArrayLoadOp : fir_Op<"array_load", [AttrSizedOperandSegments]> {
+def fir_ArrayLoadOp : fir_Op<"array_load", [AttrSizedOperandSegments,
+ DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
let summary = "Load an array as a value.";
@@ -1412,7 +1415,7 @@ def fir_ArrayLoadOp : fir_Op<"array_load", [AttrSizedOperandSegments]> {
}];
let arguments = (ins
- Arg<AnyRefOrBox, "", [MemRead]>:$memref,
+ AnyRefOrBox:$memref,
Optional<AnyShapeOrShiftType>:$shape,
Optional<fir_SliceType>:$slice,
Variadic<AnyIntegerType>:$typeparams
@@ -1624,7 +1627,7 @@ def fir_ArrayAccessOp : fir_Op<"array_access", [AttrSizedOperandSegments,
It is only possible to use `array_access` on an `array_load` result value or
a value that can be trace back transitively to an `array_load` as the
- dominating source. Other array operation such as `array_amend` can be in
+ dominating source. Other array operations such as `array_amend` can be in
between.
TODO: The above restriction is not enforced. The design of the operation
@@ -1685,7 +1688,7 @@ def fir_ArrayAmendOp : fir_Op<"array_amend", [NoMemoryEffect]> {
}
def fir_ArrayMergeStoreOp : fir_Op<"array_merge_store",
- [AttrSizedOperandSegments]> {
+ [AttrSizedOperandSegments, DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
let summary = "Store merged array value to memory.";
@@ -1714,7 +1717,7 @@ def fir_ArrayMergeStoreOp : fir_Op<"array_merge_store",
let arguments = (ins
fir_SequenceType:$original,
fir_SequenceType:$sequence,
- Arg<AnyRefOrBox, "", [MemWrite]>:$memref,
+ AnyRefOrBox:$memref,
Optional<fir_SliceType>:$slice,
Variadic<AnyIntegerType>:$typeparams
);
@@ -2752,6 +2755,22 @@ def fir_AddrOfOp : fir_OneResultOp<"address_of", [NoMemoryEffect]> {
let assemblyFormat = "`(` $symbol `)` attr-dict `:` type($resTy)";
}
+def fir_VolatileCastOp : fir_SimpleOneResultOp<"volatile_cast", [NoMemoryEffect]> {
+ let summary = "cast between volatile and non-volatile types";
+ let description = [{
+ Cast between volatile and non-volatile types. The types must be otherwise
+ identical. A value's volatility cannot be changed by a fir.convert operation.
+ Reinterpreting a value as volatile must be done explicitly using this operation.
+ }];
+ let arguments = (ins AnyRefOrBox:$value);
+ let results = (outs AnyRefOrBox:$res);
+ let assemblyFormat = [{
+ $value attr-dict `:` functional-type($value, results)
+ }];
+ let hasVerifier = 1;
+ let hasFolder = 1;
+}
+
def fir_ConvertOp : fir_SimpleOneResultOp<"convert", [NoMemoryEffect]> {
let summary = "encapsulates all Fortran entity type conversions";
diff --git a/flang/include/flang/Optimizer/Dialect/FIROpsSupport.h b/flang/include/flang/Optimizer/Dialect/FIROpsSupport.h
index f7f0a3067b318..b01d72199bf1d 100644
--- a/flang/include/flang/Optimizer/Dialect/FIROpsSupport.h
+++ b/flang/include/flang/Optimizer/Dialect/FIROpsSupport.h
@@ -15,13 +15,26 @@
namespace fir {
-/// Return true iff the Operation is a non-volatile LoadOp or ArrayLoadOp.
-inline bool nonVolatileLoad(mlir::Operation *op) {
- if (auto load = mlir::dyn_cast<fir::LoadOp>(op))
- return !load->getAttr("volatile");
- if (auto arrLoad = mlir::dyn_cast<fir::ArrayLoadOp>(op))
- return !arrLoad->getAttr("volatile");
- return false;
+/// The LLVM dialect represents volatile memory accesses as read and write
+/// effects to an unknown memory location, but this may be overly conservative.
+/// LLVM Language Reference only specifies that volatile memory accesses
+/// must not be reordered relative to other volatile memory accesses, so it
+/// is more precise to use a separate memory resource for volatile memory
+/// accesses.
+inline void addVolatileMemoryEffects(
+ mlir::TypeRange type,
+ llvm::SmallVectorImpl<
+ mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+ &effects) {
+ for (mlir::Type t : type) {
+ if (fir::isa_volatile_type(t)) {
+ effects.emplace_back(mlir::MemoryEffects::Read::get(),
+ fir::VolatileMemoryResource::get());
+ effects.emplace_back(mlir::MemoryEffects::Write::get(),
+ fir::VolatileMemoryResource::get());
+ break;
+ }
+ }
}
/// Return true iff the Operation is a call.
diff --git a/flang/lib/Lower/ConvertExprToHLFIR.cpp b/flang/lib/Lower/ConvertExprToHLFIR.cpp
index 09bc1babf079c..8f5d799ea4c57 100644
--- a/flang/lib/Lower/ConvertExprToHLFIR.cpp
+++ b/flang/lib/Lower/ConvertExprToHLFIR.cpp
@@ -415,8 +415,13 @@ class HlfirDesignatorBuilder {
.Case<fir::SequenceType>([&](fir::SequenceType seqTy) -> mlir::Type {
return fir::SequenceType::get(seqTy.getShape(), newEleTy);
})
- .Case<fir::PointerType, fir::HeapType, fir::ReferenceType, fir::BoxType,
- fir::ClassType>([&](auto t) -> mlir::Type {
+ .Case<fir::ReferenceType, fir::BoxType, fir::ClassType>(
+ [&](auto t) -> mlir::Type {
+ using FIRT = decltype(t);
+ return FIRT::get(changeElementType(t.getEleTy(), newEleTy),
+ t.isVolatile());
+ })
+ .Case<fir::PointerType, fir::HeapType>([&](auto t) -> mlir::Type {
using FIRT = decltype(t);
return FIRT::get(changeElementType(t.getEleTy(), newEleTy));
})
diff --git a/flang/lib/Optimizer/Builder/FIRBuilder.cpp b/flang/lib/Optimizer/Builder/FIRBuilder.cpp
index 7fc30ca125a87..cfacb4b47854f 100644
--- a/flang/lib/Optimizer/Builder/FIRBuilder.cpp
+++ b/flang/lib/Optimizer/Builder/FIRBuilder.cpp
@@ -577,6 +577,17 @@ mlir::Value fir::FirOpBuilder::convertWithSemantics(
return createConvert(loc, toTy, val);
}
+mlir::Value fir::FirOpBuilder::createConvertWithVolatileCast(mlir::Location loc,
+ mlir::Type toTy,
+ mlir::Value val) {
+ if (fir::isa_volatile_type(val.getType()) != fir::isa_volatile_type(toTy)) {
+ mlir::Type volatileAdjustedType = fir::updateTypeWithVolatility(
+ val.getType(), fir::isa_volatile_type(toTy));
+ val = create<fir::VolatileCastOp>(loc, volatileAdjustedType, val);
+ }
+ return createConvert(loc, toTy, val);
+}
+
mlir::Value fir::factory::createConvert(mlir::OpBuilder &builder,
mlir::Location loc, mlir::Type toTy,
mlir::Value val) {
@@ -739,19 +750,20 @@ mlir::Value fir::FirOpBuilder::createBox(mlir::Location loc,
<< itemAddr.getType();
llvm_unreachable("not a memory reference type");
}
+ const bool isVolatile = fir::isa_volatile_type(itemAddr.getType());
mlir::Type boxTy;
mlir::Value tdesc;
// Avoid to wrap a box/class with box/class.
if (mlir::isa<fir::BaseBoxType>(elementType)) {
boxTy = elementType;
} else {
- boxTy = fir::BoxType::get(elementType);
+ boxTy = fir::BoxType::get(elementType, isVolatile);
if (isPolymorphic) {
elementType = fir::updateTypeForUnlimitedPolymorphic(elementType);
if (isAssumedType)
- boxTy = fir::BoxType::get(elementType);
+ boxTy = fir::BoxType::get(elementType, isVolatile);
else
- boxTy = fir::ClassType::get(elementType);
+ boxTy = fir::ClassType::get(elementType, isVolatile);
}
}
diff --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
index 2d8017d0318d2..5eaf6b7fc240d 100644
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -29,6 +29,7 @@
#include "mlir/IR/Matchers.h"
#include "mlir/IR/OpDefinition.h"
#include "mlir/IR/PatternMatch.h"
+#include "mlir/IR/TypeRange.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TypeSwitch.h"
@@ -853,6 +854,15 @@ std::vector<mlir::Value> fir::ArrayLoadOp::getExtents() {
return {};
}
+void fir::ArrayLoadOp::getEffects(
+ llvm::SmallVectorImpl<
+ mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+ &effects) {
+ effects.emplace_back(mlir::MemoryEffects::Read::get(), &getMemrefMutable(),
+ mlir::SideEffects::DefaultResource::get());
+ addVolatileMemoryEffects({getMemref().getType()}, effects);
+}
+
llvm::LogicalResult fir::ArrayLoadOp::verify() {
auto eleTy = fir::dyn_cast_ptrOrBoxEleTy(getMemref().getType());
auto arrTy = mlir::dyn_cast<fir::SequenceType>(eleTy);
@@ -935,6 +945,15 @@ llvm::LogicalResult fir::ArrayMergeStoreOp::verify() {
return mlir::success();
}
+void fir::ArrayMergeStoreOp::getEffects(
+ llvm::SmallVectorImpl<
+ mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+ &effects) {
+ effects.emplace_back(mlir::MemoryEffects::Write::get(), &getMemrefMutable(),
+ mlir::SideEffects::DefaultResource::get());
+ addVolatileMemoryEffects({getMemref().getType()}, effects);
+}
+
//===----------------------------------------------------------------------===//
// ArrayFetchOp
//===----------------------------------------------------------------------===//
@@ -1322,6 +1341,36 @@ mlir::ParseResult fir::CmpcOp::parse(mlir::OpAsmParser &parser,
return parseCmpOp<fir::CmpcOp>(parser, result);
}
+//===----------------------------------------------------------------------===//
+// VolatileCastOp
+//===----------------------------------------------------------------------===//
+
+llvm::LogicalResult fir::VolatileCastOp::verify() {
+ mlir::Type fromType = getValue().getType();
+ mlir::Type toType = getType();
+ // Other than volatility, are the types identical?
+ const bool sameBaseType =
+ llvm::TypeSwitch<mlir::Type, bool>(fromType)
+ .Case<fir::BoxType, fir::ReferenceType, fir::ClassType>(
+ [&](auto type) {
+ using TYPE = decltype(type);
+ return mlir::isa<TYPE>(toType);
+ })
+ .Default([=](mlir::Type) { return fromType == toType; });
+ const bool sameElementType = fir::dyn_cast_ptrOrBoxEleTy(fromType) ==
+ fir::dyn_cast_ptrOrBoxEleTy(toType);
+ if (!sameBaseType || !sameElementType)
+ return emitOpError("types must be identical except for volatility ")
+ << fromType << " / " << toType;
+ return mlir::success();
+}
+
+mlir::OpFoldResult fir::VolatileCastOp::fold(FoldAdaptor adaptor) {
+ if (getValue().getType() == getType())
+ return getValue();
+ return {};
+}
+
//===----------------------------------------------------------------------===//
// ConvertOp
//===----------------------------------------------------------------------===//
@@ -1461,7 +1510,13 @@ bool fir::ConvertOp::canBeConverted(mlir::Type inType, mlir::Type outType) {
}
llvm::LogicalResult fir::ConvertOp::verify() {
- if (canBeConverted(getValue().getType(), getType()))
+ mlir::Type inType = getValue().getType();
+ mlir::Type outType = getType();
+ if (fir::isa_volatile_type(inType) != fir::isa_volatile_type(outType))
+ return emitOpError("cannot convert between volatile and non-volatile "
+ "types, use fir.volatile_cast instead ")
+ << inType << " / " << outType;
+ if (canBeConverted(inType, outType))
return mlir::success();
return emitOpError("invalid type conversion")
<< getValue().getType() << " / " << getType();
@@ -1787,6 +1842,10 @@ llvm::LogicalResult fir::EmboxOp::verify() {
return emitOpError("slice must not be provided for a scalar");
if (getSourceBox() && !mlir::isa<fir::ClassType>(getResult().getType()))
return emitOpError("source_box must be used with fir.class result type");
+ if (fir::isa_volatile_type(getMemref().getType()) !=
+ fir::isa_volatile_type(getResult().getType()))
+ return emitOpError("cannot convert between volatile and non-volatile "
+ "types, use fir.volatile_cast instead");
return mlir::success();
}
@@ -2599,6 +2658,15 @@ void fir::LoadOp::print(mlir::OpAsmPrinter &p) {
p << " : " << getMemref().getType();
}
+void fir::LoadOp::getEffects(
+ llvm::SmallVectorImpl<
+ mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+ &effects) {
+ effects.emplace_back(mlir::MemoryEffects::Read::get(), &getMemrefMutable(),
+ mlir::SideEffects::DefaultResource::get());
+ addVolatileMemoryEffects({getMemref().getType()}, effects);
+}
+
//===----------------------------------------------------------------------===//
// DoLoopOp
//===----------------------------------------------------------------------===//
@@ -3951,6 +4019,15 @@ void fir::StoreOp::build(mlir::OpBuilder &builder, mlir::OperationState &result,
build(builder, result, value, memref, {});
}
+void fir::StoreOp::getEffects(
+ llvm::SmallVectorImpl<
+ mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+ &effects) {
+ effects.emplace_back(mlir::MemoryEffects::Write::get(), &getMemrefMutable(),
+ mlir::SideEffects::DefaultResource::get());
+ addVolatileMemoryEffects({getMemref().getType()}, effects);
+}
+
//===----------------------------------------------------------------------===//
// CopyOp
//===----------------------------------------------------------------------===//
@@ -3971,6 +4048,19 @@ llvm::LogicalResult fir::CopyOp::verify() {
return mlir::success();
}
+void fir::CopyOp::getEffects(
+ llvm::SmallVectorImpl<
+ mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+ &effects) {
+ effects.emplace_back(mlir::MemoryEffects::Read::get(), &getSourceMutable(),
+ mlir::SideEffects::DefaultResource::get());
+ effects.emplace_back(mlir::MemoryEffects::Write::get(),
+ &getDestinationMutable(),
+ mlir::SideEffects::DefaultResource::get());
+ addVolatileMemoryEffects({getDestination().getType(), getSource().getType()},
+ effects);
+}
+
//===----------------------------------------------------------------------===//
// StringLitOp
//===----------------------------------------------------------------------===//
diff --git a/flang/test/Fir/cse.fir b/flang/test/Fir/cse.fir
index 8813b7c411f50..590a9681f7405 100644
--- a/flang/test/Fir/cse.fir
+++ b/flang/test/Fir/cse.fir
@@ -55,3 +55,23 @@ func.func @fun(%a : !fir.ref<i64>) -> i64 {
%5 = arith.subi %4, %4 : i64
return %5 : i64
}
+
+// -----
+
+// Check that the redundant ops on volatile operands are PRESERVED.
+func.func @fun(%arg0: !fir.ref<i64, volatile>) -> i64 {
+ %0 = fir.load %arg0 : !fir.ref<i64, volatile>
+ %1 = fir.load %arg0 : !fir.ref<i64, volatile>
+ %2 = arith.addi %0, %1 : i64
+ fir.store %2 to %arg0 : !fir.ref<i64, volatile>
+ fir.store %2 to %arg0 : !fir.ref<i64, volatile>
+ return %2 : i64
+}
+// CHECK-LABEL: func.func @fun(%arg0: !fir.ref<i64, volatile>) -> i64 {
+// CHECK: %[[VAL_1:.*]] = fir.load %arg0 : !fir.ref<i64, volatile>
+// CHECK: %[[VAL_2:.*]] = fir.load %arg0 : !fir.ref<i64, volatile>
+// CHECK: %[[VAL_3:.*]] = arith.addi %[[VAL_1]], %[[VAL_2]] : i64
+// CHECK: fir.store %[[VAL_3]] to %arg0 : !fir.ref<i64, volatile>
+// CHECK: fir.store %[[VAL_3]] to %arg0 : !fir.ref<i64, volatile>
+// CHECK: return %[[VAL_3]] : i64
+// CHECK: }
diff --git a/flang/test/Fir/invalid.fir b/flang/test/Fir/invalid.fir
index 88906890a9237..447a6c68b4b0a 100644
--- a/flang/test/Fir/...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/135039
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