[Mlir-commits] [mlir] [mlir][spirv] Allow disabling control flow structurization (PR #140561)
Igor Wodiany
llvmlistbot at llvm.org
Mon May 19 08:37:26 PDT 2025
https://github.com/IgWod-IMG created https://github.com/llvm/llvm-project/pull/140561
Currently some control flow patterns cannot be structurized into existing SPIR-V MLIR constructs, e.g., conditional early exits (break). Since the support for early exit cannot be currently added (https://github.com/llvm/llvm-project/pull/138688#pullrequestreview-2830791677 in see #138688) this patch enables structurizer to be disabled to keep the control flow unstructurized. By default, the control flow is structurized.
>From ca64017fec67ec713b63217af7ae7466bed08010 Mon Sep 17 00:00:00 2001
From: Igor Wodiany <igor.wodiany at imgtec.com>
Date: Mon, 19 May 2025 14:22:01 +0100
Subject: [PATCH] [mlir][spirv] Allow disabling control flow structurization
Currently some control flow patterns cannot be structurized
into current SPIR-V MLIR constructs, e.g., conditional early exits
(break). Since the support for early exit cannot be currently added
(https://github.com/llvm/llvm-project/pull/138688#pullrequestreview-2830791677
in see #138688) this patch enables structurizer to be disabled to
keep the control flow unstructurized. By default, the control flow
is structurized.
---
mlir/include/mlir/Target/SPIRV/Deserialization.h | 5 +++--
.../SPIRV/Deserialization/Deserialization.cpp | 7 ++++---
.../SPIRV/Deserialization/Deserializer.cpp | 16 ++++++++++++++--
.../Target/SPIRV/Deserialization/Deserializer.h | 8 +++++++-
mlir/lib/Target/SPIRV/TranslateRegistration.cpp | 14 +++++++++++---
5 files changed, 39 insertions(+), 11 deletions(-)
diff --git a/mlir/include/mlir/Target/SPIRV/Deserialization.h b/mlir/include/mlir/Target/SPIRV/Deserialization.h
index a346a7fd1e5f7..adff26298c4cc 100644
--- a/mlir/include/mlir/Target/SPIRV/Deserialization.h
+++ b/mlir/include/mlir/Target/SPIRV/Deserialization.h
@@ -27,8 +27,9 @@ class ModuleOp;
/// in the given `context`. Returns the ModuleOp on success; otherwise, reports
/// errors to the error handler registered with `context` and returns a null
/// module.
-OwningOpRef<spirv::ModuleOp> deserialize(ArrayRef<uint32_t> binary,
- MLIRContext *context);
+OwningOpRef<spirv::ModuleOp>
+deserialize(ArrayRef<uint32_t> binary, MLIRContext *context,
+ bool enableControlFlowStructurization = true);
} // namespace spirv
} // namespace mlir
diff --git a/mlir/lib/Target/SPIRV/Deserialization/Deserialization.cpp b/mlir/lib/Target/SPIRV/Deserialization/Deserialization.cpp
index 7bb8762660599..11a9de91060a8 100644
--- a/mlir/lib/Target/SPIRV/Deserialization/Deserialization.cpp
+++ b/mlir/lib/Target/SPIRV/Deserialization/Deserialization.cpp
@@ -12,9 +12,10 @@
using namespace mlir;
-OwningOpRef<spirv::ModuleOp> spirv::deserialize(ArrayRef<uint32_t> binary,
- MLIRContext *context) {
- Deserializer deserializer(binary, context);
+OwningOpRef<spirv::ModuleOp>
+spirv::deserialize(ArrayRef<uint32_t> binary, MLIRContext *context,
+ bool enableControlFlowStructurization) {
+ Deserializer deserializer(binary, context, enableControlFlowStructurization);
if (failed(deserializer.deserialize()))
return nullptr;
diff --git a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp
index 7afd6e9b25b77..1aa647485496d 100644
--- a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp
+++ b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp
@@ -49,9 +49,11 @@ static inline bool isFnEntryBlock(Block *block) {
//===----------------------------------------------------------------------===//
spirv::Deserializer::Deserializer(ArrayRef<uint32_t> binary,
- MLIRContext *context)
+ MLIRContext *context,
+ bool enableControlFlowStructurization)
: binary(binary), context(context), unknownLoc(UnknownLoc::get(context)),
- module(createModuleOp()), opBuilder(module->getRegion())
+ module(createModuleOp()), opBuilder(module->getRegion()),
+ enableControlFlowStructurization(enableControlFlowStructurization)
#ifndef NDEBUG
,
logger(llvm::dbgs())
@@ -2361,6 +2363,16 @@ LogicalResult spirv::Deserializer::splitConditionalBlocks() {
}
LogicalResult spirv::Deserializer::structurizeControlFlow() {
+ if (!enableControlFlowStructurization) {
+ LLVM_DEBUG(
+ {
+ logger.startLine()
+ << "//----- [cf] skip structurizing control flow -----//\n";
+ logger.indent();
+ });
+ return success();
+ }
+
LLVM_DEBUG({
logger.startLine()
<< "//----- [cf] start structurizing control flow -----//\n";
diff --git a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h
index bcc78e3e6508d..c1df77ba7b647 100644
--- a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h
+++ b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h
@@ -121,7 +121,10 @@ class Deserializer {
public:
/// Creates a deserializer for the given SPIR-V `binary` module.
/// The SPIR-V ModuleOp will be created into `context.
- explicit Deserializer(ArrayRef<uint32_t> binary, MLIRContext *context);
+ /// `enableControlFlowStructurization` is used to enable control flow
+ /// structurization.
+ explicit Deserializer(ArrayRef<uint32_t> binary, MLIRContext *context,
+ bool enableControlFlowStructurization);
/// Deserializes the remembered SPIR-V binary module.
LogicalResult deserialize();
@@ -622,6 +625,9 @@ class Deserializer {
/// A list of all structs which have unresolved member types.
SmallVector<DeferredStructTypeInfo, 0> deferredStructTypesInfos;
+ /// A flag to enable or disable structurizer
+ bool enableControlFlowStructurization;
+
#ifndef NDEBUG
/// A logger used to emit information during the deserialzation process.
llvm::ScopedPrinter logger;
diff --git a/mlir/lib/Target/SPIRV/TranslateRegistration.cpp b/mlir/lib/Target/SPIRV/TranslateRegistration.cpp
index ff34f02d07b73..90e5b684607be 100644
--- a/mlir/lib/Target/SPIRV/TranslateRegistration.cpp
+++ b/mlir/lib/Target/SPIRV/TranslateRegistration.cpp
@@ -37,7 +37,8 @@ using namespace mlir;
// Deserializes the SPIR-V binary module stored in the file named as
// `inputFilename` and returns a module containing the SPIR-V module.
static OwningOpRef<Operation *>
-deserializeModule(const llvm::MemoryBuffer *input, MLIRContext *context) {
+deserializeModule(const llvm::MemoryBuffer *input, MLIRContext *context,
+ bool enableControlFlowStructurization) {
context->loadDialect<spirv::SPIRVDialect>();
// Make sure the input stream can be treated as a stream of SPIR-V words
@@ -51,17 +52,24 @@ deserializeModule(const llvm::MemoryBuffer *input, MLIRContext *context) {
auto binary = llvm::ArrayRef(reinterpret_cast<const uint32_t *>(start),
size / sizeof(uint32_t));
- return spirv::deserialize(binary, context);
+ return spirv::deserialize(binary, context, enableControlFlowStructurization);
}
namespace mlir {
void registerFromSPIRVTranslation() {
+ static llvm::cl::opt<bool> noControlFlowStructurization(
+ "spirv-no-control-flow-structurization",
+ llvm::cl::desc("Disable control flow structurization to enable "
+ "deserialization of early exits (see #138688)"),
+ llvm::cl::init(false));
+
TranslateToMLIRRegistration fromBinary(
"deserialize-spirv", "deserializes the SPIR-V module",
[](llvm::SourceMgr &sourceMgr, MLIRContext *context) {
assert(sourceMgr.getNumBuffers() == 1 && "expected one buffer");
return deserializeModule(
- sourceMgr.getMemoryBuffer(sourceMgr.getMainFileID()), context);
+ sourceMgr.getMemoryBuffer(sourceMgr.getMainFileID()), context,
+ !noControlFlowStructurization);
});
}
} // namespace mlir
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