Skip to content

[MLIR][LLVM] Extend argument/result attribute support. #13

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[MLIR][LLVM] Extend argument/result attribute support. #13

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
70 changes: 48 additions & 22 deletions mlir/lib/Dialect/LLVMIR/IR/LLVMInlining.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -128,10 +128,34 @@ static Value handleByValArgument(OpBuilder &builder, Operation *callable,
return allocaOp;
}

/// Returns true if the given argument or result attribute is supported by the
/// inliner, false otherwise.
static bool isArgOrRetAttrSupported(NamedAttribute attr) {
if (attr.getName() == LLVM::LLVMDialect::getAlignAttrName())
return false;
if (attr.getName() == LLVM::LLVMDialect::getInAllocaAttrName())
return false;
if (attr.getName() == LLVM::LLVMDialect::getNoAliasAttrName())
return false;
return true;
}

namespace {
struct LLVMInlinerInterface : public DialectInlinerInterface {
using DialectInlinerInterface::DialectInlinerInterface;

LLVMInlinerInterface(Dialect *dialect)
: DialectInlinerInterface(dialect),
// Cache set of StringAttrs for fast lookup in `isLegalToInline`.
disallowedFunctionAttrs({
StringAttr::get(dialect->getContext(), "noduplicate"),
StringAttr::get(dialect->getContext(), "noinline"),
StringAttr::get(dialect->getContext(), "optnone"),
StringAttr::get(dialect->getContext(), "presplitcoroutine"),
StringAttr::get(dialect->getContext(), "returns_twice"),
StringAttr::get(dialect->getContext(), "strictfp"),
}) {}

bool isLegalToInline(Operation *call, Operation *callable,
bool wouldBeCloned) const final {
if (!wouldBeCloned)
Expand All @@ -149,24 +173,28 @@ struct LLVMInlinerInterface : public DialectInlinerInterface {
return false;
}
if (auto attrs = funcOp.getArgAttrs()) {
for (Attribute attr : *attrs) {
auto attrDict = cast<DictionaryAttr>(attr);
for (DictionaryAttr attrDict : attrs->getAsRange<DictionaryAttr>()) {
for (NamedAttribute attr : attrDict) {
if (attr.getName() == LLVM::LLVMDialect::getByValAttrName())
continue;
// TODO: Handle all argument attributes;
LLVM_DEBUG(llvm::dbgs() << "Cannot inline " << funcOp.getSymName()
<< ": unhandled argument attribute \""
<< attr.getName() << "\"\n");
return false;
if (!isArgOrRetAttrSupported(attr)) {
LLVM_DEBUG(llvm::dbgs() << "Cannot inline " << funcOp.getSymName()
<< ": unhandled argument attribute "
<< attr.getName() << "\n");
return false;
}
}
}
}
// TODO: Handle result attributes;
if (funcOp.getResAttrs()) {
LLVM_DEBUG(llvm::dbgs() << "Cannot inline " << funcOp.getSymName()
<< ": unhandled result attribute\n");
return false;
if (auto attrs = funcOp.getResAttrs()) {
for (DictionaryAttr attrDict : attrs->getAsRange<DictionaryAttr>()) {
for (NamedAttribute attr : attrDict) {
if (!isArgOrRetAttrSupported(attr)) {
LLVM_DEBUG(llvm::dbgs() << "Cannot inline " << funcOp.getSymName()
<< ": unhandled return attribute "
<< attr.getName() << "\n");
return false;
}
}
}
}
// TODO: Handle exceptions.
if (funcOp.getPersonality()) {
Expand All @@ -176,18 +204,11 @@ struct LLVMInlinerInterface : public DialectInlinerInterface {
}
if (funcOp.getPassthrough()) {
// TODO: Used attributes should not be passthrough.
DenseSet<StringAttr> disallowed(
{StringAttr::get(funcOp->getContext(), "noduplicate"),
StringAttr::get(funcOp->getContext(), "noinline"),
StringAttr::get(funcOp->getContext(), "optnone"),
StringAttr::get(funcOp->getContext(), "presplitcoroutine"),
StringAttr::get(funcOp->getContext(), "returns_twice"),
StringAttr::get(funcOp->getContext(), "strictfp")});
if (llvm::any_of(*funcOp.getPassthrough(), [&](Attribute attr) {
auto stringAttr = dyn_cast<StringAttr>(attr);
if (!stringAttr)
return false;
if (disallowed.contains(stringAttr)) {
if (disallowedFunctionAttrs.contains(stringAttr)) {
LLVM_DEBUG(llvm::dbgs()
<< "Cannot inline " << funcOp.getSymName()
<< ": found disallowed function attribute "
Expand Down Expand Up @@ -284,6 +305,11 @@ struct LLVMInlinerInterface : public DialectInlinerInterface {
// which newly inlined block was previously the entry block of the callee.
moveConstantAllocasToEntryBlock(inlinedBlocks);
}

// Keeping this (immutable) state on the interface allows us to look up
// StringAttrs instead of looking up strings, since StringAttrs are bound to
// the current context and thus cannot be initialized as static fields.
const DenseSet<StringAttr> disallowedFunctionAttrs;
};

} // end anonymous namespace
Expand Down
40 changes: 40 additions & 0 deletions mlir/test/Dialect/LLVMIR/inlining.mlir
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -396,3 +396,43 @@ llvm.func @test_byval_write_only(%ptr : !llvm.ptr) {
llvm.call @with_byval_arg(%ptr) : (!llvm.ptr) -> ()
llvm.return
}

// -----

llvm.func @ignored_attrs(%ptr : !llvm.ptr { llvm.inreg, llvm.nocapture, llvm.nofree, llvm.preallocated = i32, llvm.returned, llvm.alignstack = 32 : i64, llvm.writeonly, llvm.noundef, llvm.nonnull }, %x : i32 { llvm.zeroext }) -> (!llvm.ptr { llvm.noundef, llvm.inreg, llvm.nonnull }) {
llvm.return %ptr : !llvm.ptr
}

// CHECK-LABEL: @test_ignored_attrs
// CHECK-NOT: llvm.call
// CHECK-NEXT: llvm.return
llvm.func @test_ignored_attrs(%ptr : !llvm.ptr, %x : i32) {
llvm.call @ignored_attrs(%ptr, %x) : (!llvm.ptr, i32) -> (!llvm.ptr)
llvm.return
}

// -----

llvm.func @disallowed_arg_attr(%ptr : !llvm.ptr { llvm.align = 16 : i32 }) {
llvm.return
}

// CHECK-LABEL: @test_disallow_arg_attr
// CHECK-NEXT: llvm.call
llvm.func @test_disallow_arg_attr(%ptr : !llvm.ptr) {
llvm.call @disallowed_arg_attr(%ptr) : (!llvm.ptr) -> ()
llvm.return
}

// -----

llvm.func @disallowed_ret_attr(%ptr : !llvm.ptr) -> (!llvm.ptr { llvm.noalias }) {
llvm.return %ptr : !llvm.ptr
}

// CHECK-LABEL: @test_disallow_ret_attr
// CHECK-NEXT: llvm.call
llvm.func @test_disallow_ret_attr(%ptr : !llvm.ptr) {
llvm.call @disallowed_ret_attr(%ptr) : (!llvm.ptr) -> (!llvm.ptr)
llvm.return
}