[clang] [CIR] Upstream cir-canonicalize pass (PR #131891)
Andy Kaylor via cfe-commits
cfe-commits at lists.llvm.org
Tue Mar 18 12:18:20 PDT 2025
https://github.com/andykaylor created https://github.com/llvm/llvm-project/pull/131891
This change introduces the cir-canonicalize pass. This is a simple cir-to-cir transformation that eliminates empty scopes and redundant branches. It will be expanded in future changes to simplify other redundant instruction sequences.
MLIR verification and mlir-specific command-line option handling is also introduced here.
>From d81f7cbd9015fa05c9bfddb80772ffc4237ac91a Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Mon, 17 Mar 2025 14:49:56 -0700
Subject: [PATCH] [CIR] Upstream cir-canonicalize pass
This change introduces the cir-canonicalize pass. This is a simple
cir-to-cir transformation that eliminates empty scopes and redundant
branches. It will be expanded in future changes to simplify other
redundant instruction sequences.
MLIR verification and mlir-specific command-line option handling is
also introduced here.
---
.../clang/Basic/DiagnosticFrontendKinds.td | 8 +
clang/include/clang/CIR/CIRGenerator.h | 4 +
clang/include/clang/CIR/CIRToCIRPasses.h | 39 +++++
clang/include/clang/CIR/Dialect/Passes.h | 1 +
clang/include/clang/CIR/Dialect/Passes.td | 18 +++
clang/include/clang/CIR/MissingFeatures.h | 12 ++
clang/include/clang/Driver/Options.td | 14 +-
.../include/clang/Frontend/FrontendOptions.h | 13 +-
clang/lib/CIR/CodeGen/CIRGenModule.cpp | 8 +
clang/lib/CIR/CodeGen/CIRGenModule.h | 2 +
clang/lib/CIR/CodeGen/CIRGenerator.cpp | 2 +
.../Dialect/Transforms/CIRCanonicalize.cpp | 147 ++++++++++++++++++
.../lib/CIR/Dialect/Transforms/CMakeLists.txt | 1 +
clang/lib/CIR/FrontendAction/CIRGenAction.cpp | 30 +++-
clang/lib/CIR/FrontendAction/CMakeLists.txt | 2 +
clang/lib/CIR/Lowering/CIRPasses.cpp | 21 ++-
.../CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp | 2 +
clang/lib/Driver/ToolChains/Clang.cpp | 9 ++
clang/lib/Frontend/CompilerInvocation.cpp | 8 +
clang/lib/FrontendTool/CMakeLists.txt | 9 ++
.../ExecuteCompilerInvocation.cpp | 20 +++
clang/test/CIR/Transforms/canonicalize.cir | 72 +++++++++
clang/test/CIR/mlirargs.c | 12 ++
clang/test/CIR/mlprint.c | 14 ++
clang/tools/cir-opt/cir-opt.cpp | 4 +
clang/tools/driver/cc1as_main.cpp | 1 +
26 files changed, 468 insertions(+), 5 deletions(-)
create mode 100644 clang/include/clang/CIR/CIRToCIRPasses.h
create mode 100644 clang/lib/CIR/Dialect/Transforms/CIRCanonicalize.cpp
create mode 100644 clang/test/CIR/Transforms/canonicalize.cir
create mode 100644 clang/test/CIR/mlirargs.c
create mode 100644 clang/test/CIR/mlprint.c
diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
index 5a05f6c4e3e30..fcbbe4caf3c9d 100644
--- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -386,4 +386,12 @@ def warn_hlsl_langstd_minimal :
Warning<"support for HLSL language version %0 is incomplete, "
"recommend using %1 instead">,
InGroup<HLSLDXCCompat>;
+
+// ClangIR frontend errors
+def err_cir_to_cir_transform_failed : Error<
+ "CIR-to-CIR transformation failed">, DefaultFatal;
+
+def err_cir_verification_failed_pre_passes : Error<
+ "CIR module verification error before running CIR-to-CIR passes">,
+ DefaultFatal;
}
diff --git a/clang/include/clang/CIR/CIRGenerator.h b/clang/include/clang/CIR/CIRGenerator.h
index 414eba80b88b8..883dce9deb8e3 100644
--- a/clang/include/clang/CIR/CIRGenerator.h
+++ b/clang/include/clang/CIR/CIRGenerator.h
@@ -55,6 +55,10 @@ class CIRGenerator : public clang::ASTConsumer {
void Initialize(clang::ASTContext &astContext) override;
bool HandleTopLevelDecl(clang::DeclGroupRef group) override;
mlir::ModuleOp getModule() const;
+ mlir::MLIRContext &getMLIRContext() { return *mlirContext; };
+ const mlir::MLIRContext &getMLIRContext() const { return *mlirContext; };
+
+ bool verifyModule() const;
};
} // namespace cir
diff --git a/clang/include/clang/CIR/CIRToCIRPasses.h b/clang/include/clang/CIR/CIRToCIRPasses.h
new file mode 100644
index 0000000000000..361ebb9e9b840
--- /dev/null
+++ b/clang/include/clang/CIR/CIRToCIRPasses.h
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares an interface for running CIR-to-CIR passes.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CIR_CIRTOCIRPASSES_H
+#define CLANG_CIR_CIRTOCIRPASSES_H
+
+#include "mlir/Pass/Pass.h"
+
+#include <memory>
+
+namespace clang {
+class ASTContext;
+}
+
+namespace mlir {
+class MLIRContext;
+class ModuleOp;
+} // namespace mlir
+
+namespace cir {
+
+// Run set of cleanup/prepare/etc passes CIR <-> CIR.
+mlir::LogicalResult runCIRToCIRPasses(mlir::ModuleOp theModule,
+ mlir::MLIRContext &mlirCtx,
+ clang::ASTContext &astCtx,
+ bool enableVerifier);
+
+} // namespace cir
+
+#endif // CLANG_CIR_CIRTOCIRPASSES_H_
diff --git a/clang/include/clang/CIR/Dialect/Passes.h b/clang/include/clang/CIR/Dialect/Passes.h
index b691849dfc563..aa84241bdecf0 100644
--- a/clang/include/clang/CIR/Dialect/Passes.h
+++ b/clang/include/clang/CIR/Dialect/Passes.h
@@ -20,6 +20,7 @@ class ASTContext;
}
namespace mlir {
+std::unique_ptr<Pass> createCIRCanonicalizePass();
std::unique_ptr<Pass> createCIRFlattenCFGPass();
void populateCIRPreLoweringPasses(mlir::OpPassManager &pm);
diff --git a/clang/include/clang/CIR/Dialect/Passes.td b/clang/include/clang/CIR/Dialect/Passes.td
index 84b7ecba2630a..1d9707541e917 100644
--- a/clang/include/clang/CIR/Dialect/Passes.td
+++ b/clang/include/clang/CIR/Dialect/Passes.td
@@ -11,6 +11,24 @@
include "mlir/Pass/PassBase.td"
+def CIRCanonicalize : Pass<"cir-canonicalize"> {
+ let summary = "Performs CIR canonicalization";
+ let description = [{
+ Perform canonicalizations on CIR and removes some redundant operations.
+
+ This pass performs basic cleanup and canonicalization transformations that
+ hopefully do not affect CIR-to-source fidelity and high-level code analysis
+ passes too much. Example transformations performed in this pass include
+ empty scope cleanup, trivial try cleanup, redundant branch cleanup, etc.
+ Those more "heavyweight" transformations and those transformations that
+ could significantly affect CIR-to-source fidelity are performed in the
+ `cir-simplify` pass.
+ }];
+
+ let constructor = "mlir::createCIRCanonicalizePass()";
+ let dependentDialects = ["cir::CIRDialect"];
+}
+
def CIRFlattenCFG : Pass<"cir-flatten-cfg"> {
let summary = "Produces flatten CFG";
let description = [{
diff --git a/clang/include/clang/CIR/MissingFeatures.h b/clang/include/clang/CIR/MissingFeatures.h
index 6adff30f5c91a..52bf56727a51b 100644
--- a/clang/include/clang/CIR/MissingFeatures.h
+++ b/clang/include/clang/CIR/MissingFeatures.h
@@ -103,6 +103,18 @@ struct MissingFeatures {
static bool scalableVectors() { return false; }
static bool unsizedTypes() { return false; }
static bool vectorType() { return false; }
+
+ // Future CIR operations
+ static bool labelOp() { return false; }
+ static bool brCondOp() { return false; }
+ static bool switchOp() { return false; }
+ static bool tryOp() { return false; }
+ static bool unaryOp() { return false; }
+ static bool selectOp() { return false; }
+ static bool complexCreateOp() { return false; }
+ static bool complexRealOp() { return false; }
+ static bool complexImagOp() { return false; }
+ static bool callOp() { return false; }
};
} // namespace cir
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 66ae8f1c7f064..75d00b5b32cd4 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2978,6 +2978,15 @@ def fapple_link_rtlib : Flag<["-"], "fapple-link-rtlib">, Group<f_Group>,
HelpText<"Force linking the clang builtins runtime library">;
/// ClangIR-specific options - BEGIN
+def clangir_disable_passes : Flag<["-"], "clangir-disable-passes">,
+ Visibility<[ClangOption, CC1Option]>,
+ HelpText<"Disable CIR transformations pipeline">,
+ MarshallingInfoFlag<FrontendOpts<"ClangIRDisablePasses">>;
+def clangir_disable_verifier : Flag<["-"], "clangir-disable-verifier">,
+ Visibility<[ClangOption, CC1Option]>,
+ HelpText<"ClangIR: Disable MLIR module verifier">,
+ MarshallingInfoFlag<FrontendOpts<"ClangIRDisableCIRVerifier">>;
+
defm clangir : BoolFOption<"clangir",
FrontendOpts<"UseClangIRPipeline">, DefaultFalse,
PosFlag<SetTrue, [], [ClangOption, CC1Option], "Use the ClangIR pipeline to compile">,
@@ -4822,8 +4831,9 @@ def : Joined<["-"], "mllvm=">,
Visibility<[ClangOption, CLOption, DXCOption, FlangOption]>, Alias<mllvm>,
HelpText<"Alias for -mllvm">, MetaVarName<"<arg>">;
def mmlir : Separate<["-"], "mmlir">,
- Visibility<[ClangOption, CLOption, FC1Option, FlangOption]>,
- HelpText<"Additional arguments to forward to MLIR's option processing">;
+ Visibility<[ClangOption, CC1Option, FC1Option, FlangOption]>,
+ HelpText<"Additional arguments to forward to MLIR's option processing">,
+ MarshallingInfoStringVector<FrontendOpts<"MLIRArgs">>;
def ffuchsia_api_level_EQ : Joined<["-"], "ffuchsia-api-level=">,
Group<m_Group>, Visibility<[ClangOption, CC1Option]>,
HelpText<"Set Fuchsia API level">,
diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
index 99b2d9a98ed1f..0e0cbaa537332 100644
--- a/clang/include/clang/Frontend/FrontendOptions.h
+++ b/clang/include/clang/Frontend/FrontendOptions.h
@@ -412,6 +412,12 @@ class FrontendOptions {
LLVM_PREFERRED_TYPE(bool)
unsigned UseClangIRPipeline : 1;
+ /// Disable Clang IR specific (CIR) passes
+ unsigned ClangIRDisablePasses : 1;
+
+ /// Disable Clang IR (CIR) verifier
+ unsigned ClangIRDisableCIRVerifier : 1;
+
CodeCompleteOptions CodeCompleteOpts;
/// Specifies the output format of the AST.
@@ -488,6 +494,10 @@ class FrontendOptions {
/// should only be used for debugging and experimental features.
std::vector<std::string> LLVMArgs;
+ /// A list of arguments to forward to MLIR's option processing; this
+ /// should only be used for debugging and experimental features.
+ std::vector<std::string> MLIRArgs;
+
/// File name of the file that will provide record layouts
/// (in the format produced by -fdump-record-layouts).
std::string OverrideRecordLayoutsFile;
@@ -533,7 +543,8 @@ class FrontendOptions {
EmitExtensionSymbolGraphs(false),
EmitSymbolGraphSymbolLabelsForTesting(false),
EmitPrettySymbolGraphs(false), GenReducedBMI(false),
- UseClangIRPipeline(false), TimeTraceGranularity(500),
+ UseClangIRPipeline(false), ClangIRDisablePasses(false),
+ ClangIRDisableCIRVerifier(false), TimeTraceGranularity(500),
TimeTraceVerbose(false) {}
/// getInputKindForExtension - Return the appropriate input kind for a file
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 0e3e15ca2cadc..36bfc2cdf6f02 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -23,6 +23,7 @@
#include "mlir/IR/BuiltinOps.h"
#include "mlir/IR/Location.h"
#include "mlir/IR/MLIRContext.h"
+#include "mlir/IR/Verifier.h"
using namespace clang;
using namespace clang::CIRGen;
@@ -488,6 +489,13 @@ mlir::Type CIRGenModule::convertType(QualType type) {
return genTypes.convertType(type);
}
+bool CIRGenModule::verifyModule() const {
+ // Verify the module after we have finished constructing it, this will
+ // check the structural properties of the IR and invoke any specific
+ // verifiers we have on the CIR operations.
+ return mlir::verify(theModule).succeeded();
+}
+
DiagnosticBuilder CIRGenModule::errorNYI(SourceLocation loc,
llvm::StringRef feature) {
unsigned diagID = diags.getCustomDiagID(
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.h b/clang/lib/CIR/CodeGen/CIRGenModule.h
index 2a798f4cd56a9..734cafa2e07bb 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.h
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.h
@@ -91,6 +91,8 @@ class CIRGenModule : public CIRGenTypeCache {
void emitTopLevelDecl(clang::Decl *decl);
+ bool verifyModule() const;
+
/// Return the address of the given function. If funcType is non-null, then
/// this function will use the specified type if it has to create it.
// TODO: this is a bit weird as `GetAddr` given we give back a FuncOp?
diff --git a/clang/lib/CIR/CodeGen/CIRGenerator.cpp b/clang/lib/CIR/CodeGen/CIRGenerator.cpp
index 6fa31ab707139..33f0c292c7710 100644
--- a/clang/lib/CIR/CodeGen/CIRGenerator.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenerator.cpp
@@ -40,6 +40,8 @@ void CIRGenerator::Initialize(ASTContext &astContext) {
*mlirContext.get(), astContext, codeGenOpts, diags);
}
+bool CIRGenerator::verifyModule() const { return cgm->verifyModule(); }
+
mlir::ModuleOp CIRGenerator::getModule() const { return cgm->getModule(); }
bool CIRGenerator::HandleTopLevelDecl(DeclGroupRef group) {
diff --git a/clang/lib/CIR/Dialect/Transforms/CIRCanonicalize.cpp b/clang/lib/CIR/Dialect/Transforms/CIRCanonicalize.cpp
new file mode 100644
index 0000000000000..8aa73ea5c1d2a
--- /dev/null
+++ b/clang/lib/CIR/Dialect/Transforms/CIRCanonicalize.cpp
@@ -0,0 +1,147 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements pass that canonicalizes CIR operations, eliminating
+// redundant branches, empty scopes, and other unnecessary operations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PassDetail.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/IR/Block.h"
+#include "mlir/IR/Operation.h"
+#include "mlir/IR/PatternMatch.h"
+#include "mlir/IR/Region.h"
+#include "mlir/Support/LogicalResult.h"
+#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
+#include "clang/CIR/Dialect/IR/CIRDialect.h"
+#include "clang/CIR/Dialect/Passes.h"
+#include "clang/CIR/MissingFeatures.h"
+
+using namespace mlir;
+using namespace cir;
+
+namespace {
+
+/// Removes branches between two blocks if it is the only branch.
+///
+/// From:
+/// ^bb0:
+/// cir.br ^bb1
+/// ^bb1: // pred: ^bb0
+/// cir.return
+///
+/// To:
+/// ^bb0:
+/// cir.return
+struct RemoveRedundantBranches : public OpRewritePattern<BrOp> {
+ using OpRewritePattern<BrOp>::OpRewritePattern;
+
+ LogicalResult matchAndRewrite(BrOp op,
+ PatternRewriter &rewriter) const final {
+ Block *block = op.getOperation()->getBlock();
+ Block *dest = op.getDest();
+
+ assert(!cir::MissingFeatures::labelOp());
+
+ // Single edge between blocks: merge it.
+ if (block->getNumSuccessors() == 1 &&
+ dest->getSinglePredecessor() == block) {
+ rewriter.eraseOp(op);
+ rewriter.mergeBlocks(dest, block);
+ return success();
+ }
+
+ return failure();
+ }
+};
+
+struct RemoveEmptyScope
+ : public OpRewritePattern<ScopeOp>::SplitMatchAndRewrite {
+ using SplitMatchAndRewrite::SplitMatchAndRewrite;
+
+ LogicalResult match(ScopeOp op) const final {
+ // TODO: Remove this logic once CIR uses MLIR infrastructure to remove
+ // trivially dead operations
+ if (op.isEmpty()) {
+ return success();
+ }
+
+ Region *region = &(op.getScopeRegion()); // getRegions().front();
+ if (region && region->getBlocks().front().getOperations().size() == 1) {
+ return success(isa<YieldOp>(region->getBlocks().front().front()));
+ }
+
+ return failure();
+ }
+
+ void rewrite(ScopeOp op, PatternRewriter &rewriter) const final {
+ rewriter.eraseOp(op);
+ }
+};
+
+//===----------------------------------------------------------------------===//
+// CIRCanonicalizePass
+//===----------------------------------------------------------------------===//
+
+struct CIRCanonicalizePass : public CIRCanonicalizeBase<CIRCanonicalizePass> {
+ using CIRCanonicalizeBase::CIRCanonicalizeBase;
+
+ // The same operation rewriting done here could have been performed
+ // by CanonicalizerPass (adding hasCanonicalizer for target Ops and
+ // implementing the same from above in CIRDialects.cpp). However, it's
+ // currently too aggressive for static analysis purposes, since it might
+ // remove things where a diagnostic can be generated.
+ //
+ // FIXME: perhaps we can add one more mode to GreedyRewriteConfig to
+ // disable this behavior.
+ void runOnOperation() override;
+};
+
+void populateCIRCanonicalizePatterns(RewritePatternSet &patterns) {
+ // clang-format off
+ patterns.add<
+ RemoveRedundantBranches,
+ RemoveEmptyScope
+ >(patterns.getContext());
+ // clang-format on
+}
+
+void CIRCanonicalizePass::runOnOperation() {
+ // Collect rewrite patterns.
+ RewritePatternSet patterns(&getContext());
+ populateCIRCanonicalizePatterns(patterns);
+
+ // Collect operations to apply patterns.
+ llvm::SmallVector<Operation *, 16> ops;
+ getOperation()->walk([&](Operation *op) {
+ assert(!cir::MissingFeatures::brCondOp());
+ assert(!cir::MissingFeatures::switchOp());
+ assert(!cir::MissingFeatures::tryOp());
+ assert(!cir::MissingFeatures::unaryOp());
+ assert(!cir::MissingFeatures::selectOp());
+ assert(!cir::MissingFeatures::complexCreateOp());
+ assert(!cir::MissingFeatures::complexRealOp());
+ assert(!cir::MissingFeatures::complexImagOp());
+ assert(!cir::MissingFeatures::callOp());
+ // CastOp here is to perform a manual `fold` in
+ // applyOpPatternsGreedily
+ if (isa<BrOp, ScopeOp, CastOp>(op))
+ ops.push_back(op);
+ });
+
+ // Apply patterns.
+ if (applyOpPatternsGreedily(ops, std::move(patterns)).failed())
+ signalPassFailure();
+}
+
+} // namespace
+
+std::unique_ptr<Pass> mlir::createCIRCanonicalizePass() {
+ return std::make_unique<CIRCanonicalizePass>();
+}
diff --git a/clang/lib/CIR/Dialect/Transforms/CMakeLists.txt b/clang/lib/CIR/Dialect/Transforms/CMakeLists.txt
index aa27074cc6131..648666d2461de 100644
--- a/clang/lib/CIR/Dialect/Transforms/CMakeLists.txt
+++ b/clang/lib/CIR/Dialect/Transforms/CMakeLists.txt
@@ -1,4 +1,5 @@
add_clang_library(MLIRCIRTransforms
+ CIRCanonicalize.cpp
FlattenCFG.cpp
DEPENDS
diff --git a/clang/lib/CIR/FrontendAction/CIRGenAction.cpp b/clang/lib/CIR/FrontendAction/CIRGenAction.cpp
index 0f686a36b982b..8ef2e8fe15db7 100644
--- a/clang/lib/CIR/FrontendAction/CIRGenAction.cpp
+++ b/clang/lib/CIR/FrontendAction/CIRGenAction.cpp
@@ -9,7 +9,9 @@
#include "clang/CIR/FrontendAction/CIRGenAction.h"
#include "mlir/IR/MLIRContext.h"
#include "mlir/IR/OwningOpRef.h"
+#include "clang/Basic/DiagnosticFrontend.h"
#include "clang/CIR/CIRGenerator.h"
+#include "clang/CIR/CIRToCIRPasses.h"
#include "clang/CIR/LowerToLLVM.h"
#include "clang/CodeGen/BackendUtil.h"
#include "clang/Frontend/CompilerInstance.h"
@@ -59,6 +61,7 @@ class CIRGenConsumer : public clang::ASTConsumer {
ASTContext *Context{nullptr};
IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
std::unique_ptr<CIRGenerator> Gen;
+ const FrontendOptions &FEOptions;
public:
CIRGenConsumer(CIRGenAction::OutputType Action, CompilerInstance &CI,
@@ -66,7 +69,8 @@ class CIRGenConsumer : public clang::ASTConsumer {
: Action(Action), CI(CI), OutputStream(std::move(OS)),
FS(&CI.getVirtualFileSystem()),
Gen(std::make_unique<CIRGenerator>(CI.getDiagnostics(), std::move(FS),
- CI.getCodeGenOpts())) {}
+ CI.getCodeGenOpts())),
+ FEOptions(CI.getFrontendOpts()) {}
void Initialize(ASTContext &Ctx) override {
assert(!Context && "initialized multiple times");
@@ -81,7 +85,31 @@ class CIRGenConsumer : public clang::ASTConsumer {
void HandleTranslationUnit(ASTContext &C) override {
Gen->HandleTranslationUnit(C);
+
+ if (!FEOptions.ClangIRDisableCIRVerifier) {
+ if (!Gen->verifyModule()) {
+ CI.getDiagnostics().Report(
+ diag::err_cir_verification_failed_pre_passes);
+ llvm::report_fatal_error(
+ "CIR codegen: module verification error before running CIR passes");
+ return;
+ }
+ }
+
mlir::ModuleOp MlirModule = Gen->getModule();
+ mlir::MLIRContext &MlirCtx = Gen->getMLIRContext();
+
+ if (!FEOptions.ClangIRDisablePasses) {
+ // Setup and run CIR pipeline.
+ std::string passOptParsingFailure;
+ if (runCIRToCIRPasses(MlirModule, MlirCtx, C,
+ !FEOptions.ClangIRDisableCIRVerifier)
+ .failed()) {
+ CI.getDiagnostics().Report(diag::err_cir_to_cir_transform_failed);
+ return;
+ }
+ }
+
switch (Action) {
case CIRGenAction::OutputType::EmitCIR:
if (OutputStream && MlirModule) {
diff --git a/clang/lib/CIR/FrontendAction/CMakeLists.txt b/clang/lib/CIR/FrontendAction/CMakeLists.txt
index 1ebac07f44662..50d6ea7108ce1 100644
--- a/clang/lib/CIR/FrontendAction/CMakeLists.txt
+++ b/clang/lib/CIR/FrontendAction/CMakeLists.txt
@@ -15,8 +15,10 @@ add_clang_library(clangCIRFrontendAction
LINK_LIBS
clangAST
+ clangBasic
clangFrontend
clangCIR
+ clangCIRLoweringCommon
clangCIRLoweringDirectToLLVM
clangCodeGen
MLIRCIR
diff --git a/clang/lib/CIR/Lowering/CIRPasses.cpp b/clang/lib/CIR/Lowering/CIRPasses.cpp
index 235acbfee8967..1616ac6145151 100644
--- a/clang/lib/CIR/Lowering/CIRPasses.cpp
+++ b/clang/lib/CIR/Lowering/CIRPasses.cpp
@@ -11,9 +11,28 @@
//===----------------------------------------------------------------------===//
// #include "clang/AST/ASTContext.h"
+#include "mlir/IR/BuiltinOps.h"
+#include "mlir/Pass/PassManager.h"
#include "clang/CIR/Dialect/Passes.h"
+#include "llvm/Support/TimeProfiler.h"
-#include "mlir/Pass/PassManager.h"
+namespace cir {
+mlir::LogicalResult runCIRToCIRPasses(mlir::ModuleOp theModule,
+ mlir::MLIRContext &mlirContext,
+ clang::ASTContext &astContext,
+ bool enableVerifier) {
+
+ llvm::TimeTraceScope scope("CIR To CIR Passes");
+
+ mlir::PassManager pm(&mlirContext);
+ pm.addPass(mlir::createCIRCanonicalizePass());
+
+ pm.enableVerifier(enableVerifier);
+ (void)mlir::applyPassManagerCLOptions(pm);
+ return pm.run(theModule);
+}
+
+} // namespace cir
namespace mlir {
diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 93d83f2e822ca..db94cf511ba63 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -1115,6 +1115,8 @@ lowerDirectlyFromCIRToLLVMIR(mlir::ModuleOp mlirModule, LLVMContext &llvmCtx) {
mlir::PassManager pm(mlirCtx);
populateCIRToLLVMPasses(pm);
+ (void)mlir::applyPassManagerCLOptions(pm);
+
if (mlir::failed(pm.run(mlirModule))) {
// FIXME: Handle any errors where they occurs and return a nullptr here.
report_fatal_error(
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 1012128085c7a..fa4fb412fe8b2 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5520,6 +5520,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
options::OPT_Wa_COMMA,
options::OPT_Xassembler,
options::OPT_mllvm,
+ options::OPT_mmlir,
};
for (const auto &A : Args)
if (llvm::is_contained(kBitcodeOptionIgnorelist, A->getOption().getID()))
@@ -7778,6 +7779,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
// features enabled through -Xclang -target-feature flags.
SanitizeArgs.addArgs(TC, Args, CmdArgs, InputType);
+#if CLANG_ENABLE_CIR
+ // Forward -mmlir arguments to to the MLIR option parser.
+ for (const Arg *A : Args.filtered(options::OPT_mmlir)) {
+ A->claim();
+ A->render(Args, CmdArgs);
+ }
+#endif // CLANG_ENABLE_CIR
+
// With -save-temps, we want to save the unoptimized bitcode output from the
// CompileJobAction, use -disable-llvm-passes to get pristine IR generated
// by the frontend.
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index e708bee464c5c..b2d8d124a3a6f 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3105,6 +3105,14 @@ static bool ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
if (Args.hasArg(OPT_fclangir) || Args.hasArg(OPT_emit_cir))
Opts.UseClangIRPipeline = true;
+#if CLANG_ENABLE_CIR
+ if (Args.hasArg(OPT_clangir_disable_passes))
+ Opts.ClangIRDisablePasses = true;
+
+ if (Args.hasArg(OPT_clangir_disable_verifier))
+ Opts.ClangIRDisableCIRVerifier = true;
+#endif // CLANG_ENABLE_CIR
+
if (Args.hasArg(OPT_aux_target_cpu))
Opts.AuxTargetCPU = std::string(Args.getLastArgValue(OPT_aux_target_cpu));
if (Args.hasArg(OPT_aux_target_feature))
diff --git a/clang/lib/FrontendTool/CMakeLists.txt b/clang/lib/FrontendTool/CMakeLists.txt
index 7c83086a7da3b..061e54c3e62d0 100644
--- a/clang/lib/FrontendTool/CMakeLists.txt
+++ b/clang/lib/FrontendTool/CMakeLists.txt
@@ -20,8 +20,17 @@ if(CLANG_ENABLE_CIR)
)
list(APPEND link_libs
clangCIRFrontendAction
+ MLIRCIRTransforms
MLIRIR
+ MLIRPass
)
+ list(APPEND deps
+ MLIRBuiltinLocationAttributesIncGen
+ MLIRBuiltinTypeInterfacesIncGen
+ )
+
+ include_directories(${LLVM_MAIN_SRC_DIR}/../mlir/include)
+ include_directories(${CMAKE_BINARY_DIR}/tools/mlir/include)
endif()
if(CLANG_ENABLE_STATIC_ANALYZER)
diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index bb3bb0aac78bf..6fc587f4de9de 100644
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -32,6 +32,10 @@
#include "llvm/Support/ErrorHandling.h"
#if CLANG_ENABLE_CIR
+#include "mlir/IR/AsmState.h"
+#include "mlir/IR/MLIRContext.h"
+#include "mlir/Pass/PassManager.h"
+#include "clang/CIR/Dialect/Passes.h"
#include "clang/CIR/FrontendAction/CIRGenAction.h"
#endif
@@ -270,6 +274,22 @@ bool ExecuteCompilerInvocation(CompilerInstance *Clang) {
}
#endif
+#if CLANG_ENABLE_CIR
+ if (!Clang->getFrontendOpts().MLIRArgs.empty()) {
+ mlir::registerCIRPasses();
+ mlir::registerMLIRContextCLOptions();
+ mlir::registerPassManagerCLOptions();
+ mlir::registerAsmPrinterCLOptions();
+ unsigned NumArgs = Clang->getFrontendOpts().MLIRArgs.size();
+ auto Args = std::make_unique<const char *[]>(NumArgs + 2);
+ Args[0] = "clang (MLIR option parsing)";
+ for (unsigned i = 0; i != NumArgs; ++i)
+ Args[i + 1] = Clang->getFrontendOpts().MLIRArgs[i].c_str();
+ Args[NumArgs + 1] = nullptr;
+ llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args.get());
+ }
+#endif
+
// If there were errors in processing arguments, don't do anything else.
if (Clang->getDiagnostics().hasErrorOccurred())
return false;
diff --git a/clang/test/CIR/Transforms/canonicalize.cir b/clang/test/CIR/Transforms/canonicalize.cir
new file mode 100644
index 0000000000000..925746a90bf19
--- /dev/null
+++ b/clang/test/CIR/Transforms/canonicalize.cir
@@ -0,0 +1,72 @@
+// RUN: cir-opt %s -cir-canonicalize -o - | FileCheck %s
+
+module {
+ cir.func @redundant_br() {
+ cir.br ^bb1
+ ^bb1: // pred: ^bb0
+ %0 = cir.alloca !cir.int<u, 32>, !cir.ptr<!cir.int<u, 32>>, ["a", init] {alignment = 4 : i64}
+ %1 = cir.const #cir.int<4> : !cir.int<u, 32>
+ cir.store %1, %0 : !cir.int<u, 32>, !cir.ptr<!cir.int<u, 32>>
+ cir.br ^bb2
+ ^bb2: // pred: ^bb1
+ cir.return
+ }
+ // CHECK: cir.func @redundant_br() {
+ // CHECK-NOT: ^
+ // CHECK: %[[A:.*]] = cir.alloca !cir.int<u, 32>, !cir.ptr<!cir.int<u, 32>>, ["a", init] {alignment = 4 : i64}
+ // CHECK: %[[FOUR:.*]] = cir.const #cir.int<4> : !cir.int<u, 32>
+ // CHECK: cir.store %[[FOUR]], %[[A]] : !cir.int<u, 32>, !cir.ptr<!cir.int<u, 32>>
+ // CHECK-NOT: cir.br
+ // CHECK-NOT: ^
+ // CHECK: cir.return
+ // CHECK: }
+
+ cir.func @empty_scope() {
+ cir.scope {
+ }
+ cir.return
+ }
+ // CHECK: cir.func @empty_scope() {
+ // CHECK-NOT: cir.scope
+ // CHECK: cir.return
+ // CHECK: }
+
+ cir.func @cast1(%arg0: !cir.bool) -> !cir.bool {
+ %0 = cir.cast(bool_to_int, %arg0 : !cir.bool), !cir.int<s, 32>
+ %1 = cir.cast(int_to_bool, %0 : !cir.int<s, 32>), !cir.bool
+ cir.return %1 : !cir.bool
+ }
+ // CHECK: cir.func @cast1(%[[ARG0:.*]]: !cir.bool) -> !cir.bool
+ // CHECK-NOT: cir.cast
+ // CHECK: cir.return %[[ARG0]] : !cir.bool
+
+ cir.func @cast2(%arg0: !cir.int<s, 32>) -> !cir.bool {
+ %0 = cir.cast(int_to_bool, %arg0 : !cir.int<s, 32>), !cir.bool
+ %1 = cir.cast(bool_to_int, %0 : !cir.bool), !cir.int<s, 32>
+ %2 = cir.cast(integral, %1 : !cir.int<s, 32>), !cir.int<s, 64>
+ %3 = cir.cast(int_to_bool, %2 : !cir.int<s, 64>), !cir.bool
+ cir.return %3 : !cir.bool
+ }
+ // CHECK: cir.func @cast2(%[[ARG0:.*]]: !cir.int<s, 32>) -> !cir.bool
+ // CHECK: %[[CAST:.*]] = cir.cast(int_to_bool, %[[ARG0]] : !cir.int<s, 32>), !cir.bool
+ // CHECK-NOT: cir.cast
+ // CHECK: cir.return %[[CAST]] : !cir.bool
+
+ cir.func @no_fold_cast(%arg0: !cir.int<s, 32>) -> !cir.int<s, 64> {
+ %0 = cir.cast(int_to_bool, %arg0 : !cir.int<s, 32>), !cir.bool
+ %1 = cir.cast(bool_to_int, %0 : !cir.bool), !cir.int<s, 32>
+ %2 = cir.cast(integral, %1 : !cir.int<s, 32>), !cir.int<s, 64>
+ cir.return %2 : !cir.int<s, 64>
+ }
+ // CHECK: cir.func @no_fold_cast(%[[ARG0:.*]]: !cir.int<s, 32>) -> !cir.int<s, 64>
+ // CHECK: %[[CAST:.*]] = cir.cast(int_to_bool, %[[ARG0]] : !cir.int<s, 32>), !cir.bool
+ // CHECK: %[[CAST2:.*]] = cir.cast(bool_to_int, %[[CAST]] : !cir.bool), !cir.int<s, 32>
+ // CHECK: %[[CAST3:.*]] = cir.cast(integral, %[[CAST2]] : !cir.int<s, 32>), !cir.int<s, 64>
+ // CHECK: cir.return %[[CAST3]] : !cir.int<s, 64>
+
+}
+
+
+
+
+
diff --git a/clang/test/CIR/mlirargs.c b/clang/test/CIR/mlirargs.c
new file mode 100644
index 0000000000000..cfb07197ef185
--- /dev/null
+++ b/clang/test/CIR/mlirargs.c
@@ -0,0 +1,12 @@
+// Clang returns 1 when wrong arguments are given.
+// RUN: not %clang_cc1 -mmlir -mlir-disable-threadingd -mmlir -mlir-print-op-genericd 2>&1 | FileCheck %s --check-prefix=WRONG
+// Test that the driver can pass mlir args to cc1.
+// RUN: %clang -### -mmlir -mlir-disable-threading %s 2>&1 | FileCheck %s --check-prefix=CC1
+
+
+// WRONG: clang (MLIR option parsing): Unknown command line argument '-mlir-disable-threadingd'. Try: 'clang (MLIR option parsing) --help'
+// WRONG: clang (MLIR option parsing): Did you mean '--mlir-disable-threading'?
+// WRONG: clang (MLIR option parsing): Unknown command line argument '-mlir-print-op-genericd'. Try: 'clang (MLIR option parsing) --help'
+// WRONG: clang (MLIR option parsing): Did you mean '--mlir-print-op-generic'?
+
+// CC1: "-mmlir" "-mlir-disable-threading"
diff --git a/clang/test/CIR/mlprint.c b/clang/test/CIR/mlprint.c
new file mode 100644
index 0000000000000..51ebe526a02e6
--- /dev/null
+++ b/clang/test/CIR/mlprint.c
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir -mmlir --mlir-print-ir-after-all %s -o %t.cir 2>&1 | FileCheck %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm -mmlir --mlir-print-ir-after-all -mllvm -print-after-all %s -o %t.ll 2>&1 | FileCheck %s -check-prefix=CIR -check-prefix=LLVM
+
+int foo(void) {
+ int i = 3;
+ return i;
+}
+
+// CIR: IR Dump After CIRCanonicalize (cir-canonicalize)
+// CIR: cir.func @foo() -> !cir.int<s, 32>
+// LLVM: IR Dump After cir::direct::ConvertCIRToLLVMPass (cir-flat-to-llvm)
+// LLVM: llvm.func @foo() -> i32
+// LLVM: IR Dump After
+// LLVM: define{{.*}} i32 @foo()
diff --git a/clang/tools/cir-opt/cir-opt.cpp b/clang/tools/cir-opt/cir-opt.cpp
index 8e9311c591a3e..79a26c7986f0b 100644
--- a/clang/tools/cir-opt/cir-opt.cpp
+++ b/clang/tools/cir-opt/cir-opt.cpp
@@ -34,6 +34,10 @@ int main(int argc, char **argv) {
registry.insert<mlir::BuiltinDialect, cir::CIRDialect,
mlir::memref::MemRefDialect, mlir::LLVM::LLVMDialect>();
+ ::mlir::registerPass([]() -> std::unique_ptr<::mlir::Pass> {
+ return mlir::createCIRCanonicalizePass();
+ });
+
mlir::PassPipelineRegistration<CIRToLLVMPipelineOptions> pipeline(
"cir-to-llvm", "",
[](mlir::OpPassManager &pm, const CIRToLLVMPipelineOptions &options) {
diff --git a/clang/tools/driver/cc1as_main.cpp b/clang/tools/driver/cc1as_main.cpp
index 7fe97cc6e6ace..d90fadcae5df3 100644
--- a/clang/tools/driver/cc1as_main.cpp
+++ b/clang/tools/driver/cc1as_main.cpp
@@ -326,6 +326,7 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
}
}
Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
+
Opts.OutputPath = std::string(Args.getLastArgValue(OPT_o));
Opts.SplitDwarfOutput =
std::string(Args.getLastArgValue(OPT_split_dwarf_output));
More information about the cfe-commits
mailing list