[clang] llvm-canon (PR #68176)
Justin Fargnoli via cfe-commits
cfe-commits at lists.llvm.org
Tue Oct 3 21:30:26 PDT 2023
https://github.com/justinfargnoli created https://github.com/llvm/llvm-project/pull/68176
Add the llvm-canon tool. Description from the [original PR](https://reviews.llvm.org/D66029#change-wZv3yOpDdxIu):
> Added a new llvm-canon tool which aims to transform LLVM Modules into a canonical form by reordering and renaming instructions while preserving the same semantics. This tool makes it easier to spot semantic differences while diffing two modules which have undergone different transformation passes.
This code was originally written by @michalpaszkowski and [submitted to mainline LLVM](https://reviews.llvm.org/rG14d358537f124a732adad1ec6edf3981dc9baece). However, it was quickly [reverted](https://reviews.llvm.org/rG335de55fa3384946f1e62050f2545c0966163236) to do some BuildBot errors.
@AidanGoldfarb and I ported the code to the new pass manager, added more tests, and fixed some bugs related to PHI nodes that may have been the root cause of the BuildBot errors that caused the patch to be reverted.
Note that this is @AidanGoldfarb and I's first time submitting to LLVM. Please liberally critique the PR!
CC @plotfi for initial review.
>From f792a030ac1761a96176332fea906cd2d1826c7b Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sat, 12 Aug 2023 10:58:45 -0700
Subject: [PATCH 01/14] Add IRCanonicalizer.cpp
---
llvm/lib/Transforms/Utils/CMakeLists.txt | 1 +
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 632 ++++++++++++++++++
2 files changed, 633 insertions(+)
create mode 100644 llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
diff --git a/llvm/lib/Transforms/Utils/CMakeLists.txt b/llvm/lib/Transforms/Utils/CMakeLists.txt
index a870071f3f641dc..7866e7a8c09c3be 100644
--- a/llvm/lib/Transforms/Utils/CMakeLists.txt
+++ b/llvm/lib/Transforms/Utils/CMakeLists.txt
@@ -34,6 +34,7 @@ add_llvm_component_library(LLVMTransformUtils
InjectTLIMappings.cpp
InstructionNamer.cpp
IntegerDivision.cpp
+ IRCanonicalizer.cpp
LCSSA.cpp
LibCallsShrinkWrap.cpp
Local.cpp
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
new file mode 100644
index 000000000000000..58e2dce0b96685b
--- /dev/null
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -0,0 +1,632 @@
+//===--------------- IRCanonicalizer.cpp - IR Canonicalizer ---------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the IRCanonicalizer class which aims to transform LLVM
+/// Modules into a canonical form by reordering and renaming instructions while
+/// preserving the same semantics. The canonicalizer makes it easier to spot
+/// semantic differences while diffing two modules which have undergone
+/// different passes.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Module.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Pass.h"
+#include "llvm/PassRegistry.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Transforms/Utils.h"
+#include <algorithm>
+#include <vector>
+
+#define DEBUG_TYPE "canon"
+
+using namespace llvm;
+
+namespace {
+/// IRCanonicalizer aims to transform LLVM IR into canonical form.
+class IRCanonicalizer : public FunctionPass {
+public:
+ static char ID;
+
+ /// \name Canonicalizer flags.
+ /// @{
+ /// Preserves original order of instructions.
+ static cl::opt<bool> PreserveOrder;
+ /// Renames all instructions (including user-named).
+ static cl::opt<bool> RenameAll;
+ /// Folds all regular instructions (including pre-outputs).
+ static cl::opt<bool> FoldPreoutputs;
+ /// Sorts and reorders operands in commutative instructions.
+ static cl::opt<bool> ReorderOperands;
+ /// @}
+
+ /// Constructor for the IRCanonicalizer.
+ IRCanonicalizer() : FunctionPass(ID) {}
+
+ bool runOnFunction(Function &F) override;
+
+private:
+ // Random constant for hashing, so the state isn't zero.
+ const uint64_t MagicHashConstant = 0x6acaa36bef8325c5ULL;
+
+ /// \name Naming.
+ /// @{
+ void nameFunctionArguments(Function &F);
+ void nameBasicBlocks(Function &F);
+ void nameInstruction(Instruction *I);
+ void nameAsInitialInstruction(Instruction *I);
+ void nameAsRegularInstruction(Instruction *I);
+ void foldInstructionName(Instruction *I);
+ /// @}
+
+ /// \name Reordering.
+ /// @{
+ void reorderInstructions(SmallVector<Instruction *, 16> &Outputs);
+ void reorderInstruction(Instruction *Used, Instruction *User,
+ SmallPtrSet<const Instruction *, 32> &Visited);
+ void reorderInstructionOperandsByNames(Instruction *I);
+ void reorderPHIIncomingValues(PHINode *PN);
+ /// @}
+
+ /// \name Utility methods.
+ /// @{
+ SmallVector<Instruction *, 16> collectOutputInstructions(Function &F);
+ bool isOutput(const Instruction *I);
+ bool isInitialInstruction(const Instruction *I);
+ bool hasOnlyImmediateOperands(const Instruction *I);
+ SetVector<int>
+ getOutputFootprint(Instruction *I,
+ SmallPtrSet<const Instruction *, 32> &Visited);
+ /// @}
+};
+} // namespace
+
+char IRCanonicalizer::ID = 0;
+static RegisterPass<IRCanonicalizer> X("canon", "Canonicalize the IR",
+ false /* Only looks at CFG */,
+ false /* Analysis Pass */);
+
+cl::opt<bool> IRCanonicalizer::PreserveOrder(
+ "preserve-order", cl::Hidden,
+ cl::desc("Preserves original instruction order"));
+cl::opt<bool> IRCanonicalizer::RenameAll(
+ "rename-all", cl::Hidden,
+ cl::desc("Renames all instructions (including user-named)"));
+cl::opt<bool> IRCanonicalizer::FoldPreoutputs(
+ "fold-all", cl::Hidden,
+ cl::desc("Folds all regular instructions (including pre-outputs)"));
+cl::opt<bool> IRCanonicalizer::ReorderOperands(
+ "reorder-operands", cl::Hidden,
+ cl::desc("Sorts and reorders operands in commutative instructions"));
+
+/// Entry method to the IRCanonicalizer.
+///
+/// \param M Module to canonicalize.
+bool IRCanonicalizer::runOnFunction(Function &F) {
+ nameFunctionArguments(F);
+ nameBasicBlocks(F);
+
+ SmallVector<Instruction *, 16> Outputs = collectOutputInstructions(F);
+
+ if (!PreserveOrder)
+ reorderInstructions(Outputs);
+
+ for (auto &I : Outputs)
+ nameInstruction(I);
+
+ for (auto &I : instructions(F)) {
+ if (!PreserveOrder) {
+ if (ReorderOperands && I.isCommutative())
+ reorderInstructionOperandsByNames(&I);
+
+ if (auto *PN = dyn_cast<PHINode>(&I))
+ reorderPHIIncomingValues(PN);
+ }
+
+ foldInstructionName(&I);
+ }
+
+ return true;
+}
+
+/// Numbers arguments.
+///
+/// \param F Function whose arguments will be renamed.
+void IRCanonicalizer::nameFunctionArguments(Function &F) {
+ int ArgumentCounter = 0;
+ for (auto &A : F.args()) {
+ if (RenameAll || A.getName().empty()) {
+ A.setName("a" + Twine(ArgumentCounter));
+ ++ArgumentCounter;
+ }
+ }
+}
+
+/// Names basic blocks using a generated hash for each basic block in
+/// a function considering the opcode and the order of output instructions.
+///
+/// \param F Function containing basic blocks to rename.
+void IRCanonicalizer::nameBasicBlocks(Function &F) {
+ for (auto &B : F) {
+ // Initialize to a magic constant, so the state isn't zero.
+ uint64_t Hash = MagicHashConstant;
+
+ // Hash considering output instruction opcodes.
+ for (auto &I : B)
+ if (isOutput(&I))
+ Hash = hashing::detail::hash_16_bytes(Hash, I.getOpcode());
+
+ if (RenameAll || B.getName().empty()) {
+ // Name basic block. Substring hash to make diffs more readable.
+ B.setName("bb" + std::to_string(Hash).substr(0, 5));
+ }
+ }
+}
+
+/// Names instructions graphically (recursive) in accordance with the
+/// def-use tree, starting from the initial instructions (defs), finishing at
+/// the output (top-most user) instructions (depth-first).
+///
+/// \param I Instruction to be renamed.
+void IRCanonicalizer::nameInstruction(Instruction *I) {
+ // Determine the type of instruction to name.
+ if (isInitialInstruction(I)) {
+ // This is an initial instruction.
+ nameAsInitialInstruction(I);
+ } else {
+ // This must be a regular instruction.
+ nameAsRegularInstruction(I);
+ }
+}
+
+/// Names instruction following the scheme:
+/// vl00000Callee(Operands)
+///
+/// Where 00000 is a hash calculated considering instruction's opcode and output
+/// footprint. Callee's name is only included when instruction's type is
+/// CallInst. In cases where instruction is commutative, operands list is also
+/// sorted.
+///
+/// Renames instruction only when RenameAll flag is raised or instruction is
+/// unnamed.
+///
+/// \see getOutputFootprint()
+/// \param I Instruction to be renamed.
+void IRCanonicalizer::nameAsInitialInstruction(Instruction *I) {
+ if (I->getType()->isVoidTy() || (!I->getName().empty() && !RenameAll))
+ return;
+
+ // Instruction operands for further sorting.
+ SmallVector<SmallString<64>, 4> Operands;
+
+ // Collect operands.
+ for (auto &OP : I->operands()) {
+ if (!isa<Function>(OP)) {
+ std::string TextRepresentation;
+ raw_string_ostream Stream(TextRepresentation);
+ OP->printAsOperand(Stream, false);
+ Operands.push_back(StringRef(Stream.str()));
+ }
+ }
+
+ if (I->isCommutative())
+ llvm::sort(Operands);
+
+ // Initialize to a magic constant, so the state isn't zero.
+ uint64_t Hash = MagicHashConstant;
+
+ // Consider instruction's opcode in the hash.
+ Hash = hashing::detail::hash_16_bytes(Hash, I->getOpcode());
+
+ SmallPtrSet<const Instruction *, 32> Visited;
+ // Get output footprint for I.
+ SetVector<int> OutputFootprint = getOutputFootprint(I, Visited);
+
+ // Consider output footprint in the hash.
+ for (const int &Output : OutputFootprint)
+ Hash = hashing::detail::hash_16_bytes(Hash, Output);
+
+ // Base instruction name.
+ SmallString<256> Name;
+ Name.append("vl" + std::to_string(Hash).substr(0, 5));
+
+ // In case of CallInst, consider callee in the instruction name.
+ if (const auto *CI = dyn_cast<CallInst>(I)) {
+ Function *F = CI->getCalledFunction();
+
+ if (F != nullptr) {
+ Name.append(F->getName());
+ }
+ }
+
+ Name.append("(");
+ for (unsigned long i = 0; i < Operands.size(); ++i) {
+ Name.append(Operands[i]);
+
+ if (i < Operands.size() - 1)
+ Name.append(", ");
+ }
+ Name.append(")");
+
+ I->setName(Name);
+}
+
+/// Names instruction following the scheme:
+/// op00000Callee(Operands)
+///
+/// Where 00000 is a hash calculated considering instruction's opcode, its
+/// operands' opcodes and order. Callee's name is only included when
+/// instruction's type is CallInst. In cases where instruction is commutative,
+/// operand list is also sorted.
+///
+/// Names instructions recursively in accordance with the def-use tree,
+/// starting from the initial instructions (defs), finishing at
+/// the output (top-most user) instructions (depth-first).
+///
+/// Renames instruction only when RenameAll flag is raised or instruction is
+/// unnamed.
+///
+/// \see getOutputFootprint()
+/// \param I Instruction to be renamed.
+void IRCanonicalizer::nameAsRegularInstruction(Instruction *I) {
+ // Instruction operands for further sorting.
+ SmallVector<SmallString<128>, 4> Operands;
+
+ // The name of a regular instruction depends
+ // on the names of its operands. Hence, all
+ // operands must be named first in the use-def
+ // walk.
+
+ // Collect operands.
+ for (auto &OP : I->operands()) {
+ if (auto *IOP = dyn_cast<Instruction>(OP)) {
+ // Walk down the use-def chain.
+ nameInstruction(IOP);
+ Operands.push_back(IOP->getName());
+ } else if (isa<Value>(OP) && !isa<Function>(OP)) {
+ // This must be an immediate value.
+ std::string TextRepresentation;
+ raw_string_ostream Stream(TextRepresentation);
+ OP->printAsOperand(Stream, false);
+ Operands.push_back(StringRef(Stream.str()));
+ }
+ }
+
+ if (I->isCommutative())
+ llvm::sort(Operands.begin(), Operands.end());
+
+ // Initialize to a magic constant, so the state isn't zero.
+ uint64_t Hash = MagicHashConstant;
+
+ // Consider instruction opcode in the hash.
+ Hash = hashing::detail::hash_16_bytes(Hash, I->getOpcode());
+
+ // Operand opcodes for further sorting (commutative).
+ SmallVector<int, 4> OperandsOpcodes;
+
+ // Collect operand opcodes for hashing.
+ for (auto &OP : I->operands())
+ if (auto *IOP = dyn_cast<Instruction>(OP))
+ OperandsOpcodes.push_back(IOP->getOpcode());
+
+ if (I->isCommutative())
+ llvm::sort(OperandsOpcodes.begin(), OperandsOpcodes.end());
+
+ // Consider operand opcodes in the hash.
+ for (const int Code : OperandsOpcodes)
+ Hash = hashing::detail::hash_16_bytes(Hash, Code);
+
+ // Base instruction name.
+ SmallString<512> Name;
+ Name.append("op" + std::to_string(Hash).substr(0, 5));
+
+ // In case of CallInst, consider callee in the instruction name.
+ if (const auto *CI = dyn_cast<CallInst>(I))
+ if (const Function *F = CI->getCalledFunction())
+ Name.append(F->getName());
+
+ Name.append("(");
+ for (unsigned long i = 0; i < Operands.size(); ++i) {
+ Name.append(Operands[i]);
+
+ if (i < Operands.size() - 1)
+ Name.append(", ");
+ }
+ Name.append(")");
+
+ if ((I->getName().empty() || RenameAll) && !I->getType()->isVoidTy())
+ I->setName(Name);
+}
+
+/// Shortens instruction's name. This method removes called function name from
+/// the instruction name and substitutes the call chain with a corresponding
+/// list of operands.
+///
+/// Examples:
+/// op00000Callee(op00001Callee(...), vl00000Callee(1, 2), ...) ->
+/// op00000(op00001, vl00000, ...) vl00000Callee(1, 2) -> vl00000(1, 2)
+///
+/// This method omits output instructions and pre-output (instructions directly
+/// used by an output instruction) instructions (by default). By default it also
+/// does not affect user named instructions.
+///
+/// \param I Instruction whose name will be folded.
+void IRCanonicalizer::foldInstructionName(Instruction *I) {
+ // If this flag is raised, fold all regular
+ // instructions (including pre-outputs).
+ if (!FoldPreoutputs) {
+ // Don't fold if one of the users is an output instruction.
+ for (auto *U : I->users())
+ if (auto *IU = dyn_cast<Instruction>(U))
+ if (isOutput(IU))
+ return;
+ }
+
+ // Don't fold if it is an output instruction or has no op prefix.
+ if (isOutput(I) || I->getName().substr(0, 2) != "op")
+ return;
+
+ // Instruction operands.
+ SmallVector<SmallString<64>, 4> Operands;
+
+ for (auto &OP : I->operands()) {
+ if (const Instruction *IOP = dyn_cast<Instruction>(OP)) {
+ bool HasCanonicalName = I->getName().substr(0, 2) == "op" ||
+ I->getName().substr(0, 2) == "vl";
+
+ Operands.push_back(HasCanonicalName ? IOP->getName().substr(0, 7)
+ : IOP->getName());
+ }
+ }
+
+ if (I->isCommutative())
+ llvm::sort(Operands.begin(), Operands.end());
+
+ SmallString<256> Name;
+ Name.append(I->getName().substr(0, 7));
+
+ Name.append("(");
+ for (unsigned long i = 0; i < Operands.size(); ++i) {
+ Name.append(Operands[i]);
+
+ if (i < Operands.size() - 1)
+ Name.append(", ");
+ }
+ Name.append(")");
+
+ I->setName(Name);
+}
+
+/// Reorders instructions by walking up the tree from each operand of an output
+/// instruction and reducing the def-use distance.
+/// This method assumes that output instructions were collected top-down,
+/// otherwise the def-use chain may be broken.
+/// This method is a wrapper for recursive reorderInstruction().
+///
+/// \see reorderInstruction()
+/// \param Outputs Vector of pointers to output instructions collected top-down.
+void IRCanonicalizer::reorderInstructions(
+ SmallVector<Instruction *, 16> &Outputs) {
+ // This method assumes output instructions were collected top-down,
+ // otherwise the def-use chain may be broken.
+
+ SmallPtrSet<const Instruction *, 32> Visited;
+
+ // Walk up the tree.
+ for (auto &I : Outputs)
+ for (auto &OP : I->operands())
+ if (auto *IOP = dyn_cast<Instruction>(OP))
+ reorderInstruction(IOP, I, Visited);
+}
+
+/// Reduces def-use distance or places instruction at the end of the basic
+/// block. Continues to walk up the def-use tree recursively. Used by
+/// reorderInstructions().
+///
+/// \see reorderInstructions()
+/// \param Used Pointer to the instruction whose value is used by the \p User.
+/// \param User Pointer to the instruction which uses the \p Used.
+/// \param Visited Set of visited instructions.
+void IRCanonicalizer::reorderInstruction(
+ Instruction *Used, Instruction *User,
+ SmallPtrSet<const Instruction *, 32> &Visited) {
+
+ if (!Visited.count(Used)) {
+ Visited.insert(Used);
+
+ if (Used->getParent() == User->getParent()) {
+ // If Used and User share the same basic block move Used just before User.
+ Used->moveBefore(User);
+ } else {
+ // Otherwise move Used to the very end of its basic block.
+ Used->moveBefore(&Used->getParent()->back());
+ }
+
+ for (auto &OP : Used->operands()) {
+ if (auto *IOP = dyn_cast<Instruction>(OP)) {
+ // Walk up the def-use tree.
+ reorderInstruction(IOP, Used, Visited);
+ }
+ }
+ }
+}
+
+/// Reorders instruction's operands alphabetically. This method assumes
+/// that passed instruction is commutative. Changing the operand order
+/// in other instructions may change the semantics.
+///
+/// \param I Instruction whose operands will be reordered.
+void IRCanonicalizer::reorderInstructionOperandsByNames(Instruction *I) {
+ // This method assumes that passed I is commutative,
+ // changing the order of operands in other instructions
+ // may change the semantics.
+
+ // Instruction operands for further sorting.
+ SmallVector<std::pair<std::string, Value *>, 4> Operands;
+
+ // Collect operands.
+ for (auto &OP : I->operands()) {
+ if (auto *VOP = dyn_cast<Value>(OP)) {
+ if (isa<Instruction>(VOP)) {
+ // This is an an instruction.
+ Operands.push_back(
+ std::pair<std::string, Value *>(VOP->getName(), VOP));
+ } else {
+ std::string TextRepresentation;
+ raw_string_ostream Stream(TextRepresentation);
+ OP->printAsOperand(Stream, false);
+ Operands.push_back(std::pair<std::string, Value *>(Stream.str(), VOP));
+ }
+ }
+ }
+
+ // Sort operands.
+ llvm::sort(Operands.begin(), Operands.end(), llvm::less_first());
+
+ // Reorder operands.
+ unsigned Position = 0;
+ for (auto &OP : I->operands()) {
+ OP.set(Operands[Position].second);
+ Position++;
+ }
+}
+
+/// Reorders PHI node's values according to the names of corresponding basic
+/// blocks.
+///
+/// \param PN PHI node to canonicalize.
+void IRCanonicalizer::reorderPHIIncomingValues(PHINode *PN) {
+ // Values for further sorting.
+ SmallVector<std::pair<Value *, BasicBlock *>, 2> Values;
+
+ // Collect blocks and corresponding values.
+ for (auto &BB : PN->blocks()) {
+ Value *V = PN->getIncomingValueForBlock(BB);
+ Values.push_back(std::pair<Value *, BasicBlock *>(V, BB));
+ }
+
+ // Sort values according to the name of a basic block.
+ llvm::sort(Values, [](const std::pair<Value *, BasicBlock *> &LHS,
+ const std::pair<Value *, BasicBlock *> &RHS) {
+ return LHS.second->getName() < RHS.second->getName();
+ });
+
+ // Swap.
+ for (unsigned i = 0; i < Values.size(); ++i) {
+ PN->setIncomingBlock(i, Values[i].second);
+ PN->setIncomingValue(i, Values[i].first);
+ }
+}
+
+/// Returns a vector of output instructions. An output is an instruction which
+/// has side-effects or is ReturnInst. Uses isOutput().
+///
+/// \see isOutput()
+/// \param F Function to collect outputs from.
+SmallVector<Instruction *, 16>
+IRCanonicalizer::collectOutputInstructions(Function &F) {
+ // Output instructions are collected top-down in each function,
+ // any change may break the def-use chain in reordering methods.
+ SmallVector<Instruction *, 16> Outputs;
+
+ for (auto &I : instructions(F))
+ if (isOutput(&I))
+ Outputs.push_back(&I);
+
+ return Outputs;
+}
+
+/// Helper method checking whether the instruction may have side effects or is
+/// ReturnInst.
+///
+/// \param I Considered instruction.
+bool IRCanonicalizer::isOutput(const Instruction *I) {
+ // Outputs are such instructions which may have side effects or is ReturnInst.
+ if (I->mayHaveSideEffects() || isa<ReturnInst>(I))
+ return true;
+
+ return false;
+}
+
+/// Helper method checking whether the instruction has users and only
+/// immediate operands.
+///
+/// \param I Considered instruction.
+bool IRCanonicalizer::isInitialInstruction(const Instruction *I) {
+ // Initial instructions are such instructions whose values are used by
+ // other instructions, yet they only depend on immediate values.
+ return !I->user_empty() && hasOnlyImmediateOperands(I);
+}
+
+/// Helper method checking whether the instruction has only immediate operands.
+///
+/// \param I Considered instruction.
+bool IRCanonicalizer::hasOnlyImmediateOperands(const Instruction *I) {
+ for (const auto &OP : I->operands())
+ if (isa<Instruction>(OP))
+ return false; // Found non-immediate operand (instruction).
+
+ return true;
+}
+
+/// Helper method returning indices (distance from the beginning of the basic
+/// block) of outputs using the \p I (eliminates repetitions). Walks down the
+/// def-use tree recursively.
+///
+/// \param I Considered instruction.
+/// \param Visited Set of visited instructions.
+SetVector<int> IRCanonicalizer::getOutputFootprint(
+ Instruction *I, SmallPtrSet<const Instruction *, 32> &Visited) {
+
+ // Vector containing indexes of outputs (no repetitions),
+ // which use I in the order of walking down the def-use tree.
+ SetVector<int> Outputs;
+
+ if (!Visited.count(I)) {
+ Visited.insert(I);
+
+ if (isOutput(I)) {
+ // Gets output instruction's parent function.
+ Function *Func = I->getParent()->getParent();
+
+ // Finds and inserts the index of the output to the vector.
+ unsigned Count = 0;
+ for (const auto &B : *Func) {
+ for (const auto &E : B) {
+ if (&E == I)
+ Outputs.insert(Count);
+ Count++;
+ }
+ }
+
+ // Returns to the used instruction.
+ return Outputs;
+ }
+
+ for (auto *U : I->users()) {
+ if (auto *UI = dyn_cast<Instruction>(U)) {
+ // Vector for outputs which use UI.
+ SetVector<int> OutputsUsingUI = getOutputFootprint(UI, Visited);
+
+ // Insert the indexes of outputs using UI.
+ Outputs.insert(OutputsUsingUI.begin(), OutputsUsingUI.end());
+ }
+ }
+ }
+
+ // Return to the used instruction.
+ return Outputs;
+}
>From d59bcfc2ccfd156e6ea152fc423feb213c169221 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sat, 12 Aug 2023 15:55:40 -0700
Subject: [PATCH 02/14] Port IRCanonicalizer to new pass manager
---
.../llvm/Transforms/Utils/IRCanonicalizer.h | 15 +++++++++++++
llvm/lib/Passes/PassBuilder.cpp | 1 +
llvm/lib/Passes/PassRegistry.def | 1 +
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 22 +++++++++----------
4 files changed, 27 insertions(+), 12 deletions(-)
create mode 100644 llvm/include/llvm/Transforms/Utils/IRCanonicalizer.h
diff --git a/llvm/include/llvm/Transforms/Utils/IRCanonicalizer.h b/llvm/include/llvm/Transforms/Utils/IRCanonicalizer.h
new file mode 100644
index 000000000000000..81bfd1bcfd2ad94
--- /dev/null
+++ b/llvm/include/llvm/Transforms/Utils/IRCanonicalizer.h
@@ -0,0 +1,15 @@
+#ifndef LLVM_TRANSFORMS_UTILS_IRCANONICALIZER_H
+#define LLVM_TRANSFORMS_UTILS_IRCANONICALIZER_H
+
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// IRCanonicalizer aims to transform LLVM IR into canonical form.
+struct IRCanonicalizerPass : public PassInfoMixin<IRCanonicalizerPass> {
+ PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+
+} // namespace llvm
+
+#endif // LLVM_TRANSFORMS_UTILS_IRCANONICALIZER_H
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index bb6b40b14f8b4c8..7b626f7df91cb39 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -237,6 +237,7 @@
#include "llvm/Transforms/Utils/HelloWorld.h"
#include "llvm/Transforms/Utils/InjectTLIMappings.h"
#include "llvm/Transforms/Utils/InstructionNamer.h"
+#include "llvm/Transforms/Utils/IRCanonicalizer.h"
#include "llvm/Transforms/Utils/LCSSA.h"
#include "llvm/Transforms/Utils/LibCallsShrinkWrap.h"
#include "llvm/Transforms/Utils/LoopSimplify.h"
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index fe24e9da9125ff7..fd30e5a8b4b58b8 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -300,6 +300,7 @@ FUNCTION_PASS("bdce", BDCEPass())
FUNCTION_PASS("bounds-checking", BoundsCheckingPass())
FUNCTION_PASS("break-crit-edges", BreakCriticalEdgesPass())
FUNCTION_PASS("callsite-splitting", CallSiteSplittingPass())
+FUNCTION_PASS("canon", IRCanonicalizerPass())
FUNCTION_PASS("consthoist", ConstantHoistingPass())
FUNCTION_PASS("count-visits", CountVisitsPass())
FUNCTION_PASS("constraint-elimination", ConstraintEliminationPass())
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index 58e2dce0b96685b..afa3d94e7f55be6 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -28,6 +28,7 @@
#include "llvm/PassRegistry.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Transforms/Utils.h"
+#include "llvm/Transforms/Utils/IRCanonicalizer.h"
#include <algorithm>
#include <vector>
@@ -37,10 +38,8 @@ using namespace llvm;
namespace {
/// IRCanonicalizer aims to transform LLVM IR into canonical form.
-class IRCanonicalizer : public FunctionPass {
+class IRCanonicalizer {
public:
- static char ID;
-
/// \name Canonicalizer flags.
/// @{
/// Preserves original order of instructions.
@@ -53,10 +52,7 @@ class IRCanonicalizer : public FunctionPass {
static cl::opt<bool> ReorderOperands;
/// @}
- /// Constructor for the IRCanonicalizer.
- IRCanonicalizer() : FunctionPass(ID) {}
-
- bool runOnFunction(Function &F) override;
+ bool runOnFunction(Function &F);
private:
// Random constant for hashing, so the state isn't zero.
@@ -94,11 +90,6 @@ class IRCanonicalizer : public FunctionPass {
};
} // namespace
-char IRCanonicalizer::ID = 0;
-static RegisterPass<IRCanonicalizer> X("canon", "Canonicalize the IR",
- false /* Only looks at CFG */,
- false /* Analysis Pass */);
-
cl::opt<bool> IRCanonicalizer::PreserveOrder(
"preserve-order", cl::Hidden,
cl::desc("Preserves original instruction order"));
@@ -630,3 +621,10 @@ SetVector<int> IRCanonicalizer::getOutputFootprint(
// Return to the used instruction.
return Outputs;
}
+
+PreservedAnalyses IRCanonicalizerPass::run(Function &F,
+ FunctionAnalysisManager &AM) {
+ errs() << F.getName() << "\n";
+ IRCanonicalizer{}.runOnFunction(F);
+ return PreservedAnalyses::all();
+}
>From 0c94ebab9a31092edfc409df6ffa922269fcf867 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sat, 12 Aug 2023 16:06:29 -0700
Subject: [PATCH 03/14] Port doc updates
---
llvm/docs/Passes.rst | 8 ++++++++
llvm/docs/ReleaseNotes.rst | 5 ++++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/llvm/docs/Passes.rst b/llvm/docs/Passes.rst
index 541e23677debf90..418ab17eb35e259 100644
--- a/llvm/docs/Passes.rst
+++ b/llvm/docs/Passes.rst
@@ -653,6 +653,14 @@ variables with initializers are marked as internal.
An interprocedural variant of :ref:`Sparse Conditional Constant Propagation
<passes-sccp>`.
+``-ir-canonicalizer``: Transforms IR into canonical form
+--------------------------------------------------------
+
+This pass aims to transform LLVM Modules into a canonical form by reordering and
+renaming instructions while preserving the same semantics. The canonicalizer makes
+it easier to spot semantic differences while diffing two modules which have undergone
+two different passes.
+
``-jump-threading``: Jump Threading
-----------------------------------
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 8eb8affb5eba9e2..dec2eec7566929e 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -42,7 +42,10 @@ Non-comprehensive list of changes in this release
functionality, or simply have a lot to talk about), see the `NOTE` below
for adding a new subsection.
-* ...
+* Added a new IRCanonicalizer pass which aims to transform LLVM modules into
+ a canonical form by reordering and renaming instructions while preserving the
+ same semantics. The canonicalizer makes it easier to spot semantic differences
+ when diffing two modules which have undergone different passes.
Update on required toolchains to build LLVM
-------------------------------------------
>From 9dbcab1948bba93e61d80a10038ab471f99e1448 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sat, 12 Aug 2023 16:29:46 -0700
Subject: [PATCH 04/14] Port tests
---
.../IRCanonicalizer/naming-arguments.ll | 7 ++++++
.../IRCanonicalizer/naming-basic-blocks.ll | 8 +++++++
.../IRCanonicalizer/naming-instructions.ll | 12 ++++++++++
.../reordering-instructions.ll | 14 +++++++++++
.../reordering-phi-node-values.ll | 24 +++++++++++++++++++
5 files changed, 65 insertions(+)
create mode 100644 llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
create mode 100644 llvm/test/Transforms/IRCanonicalizer/naming-basic-blocks.ll
create mode 100644 llvm/test/Transforms/IRCanonicalizer/naming-instructions.ll
create mode 100644 llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
create mode 100644 llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll b/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
new file mode 100644
index 000000000000000..b3f7630abd042f1
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
@@ -0,0 +1,7 @@
+; RUN: opt -S -passes=canon < %s | FileCheck %s
+
+; CHECK: @foo(i32 %a0, i32 %a1)
+define i32 @foo(i32, i32) {
+ %tmp = mul i32 %0, %1
+ ret i32 %tmp
+}
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-basic-blocks.ll b/llvm/test/Transforms/IRCanonicalizer/naming-basic-blocks.ll
new file mode 100644
index 000000000000000..79e526f8efb7ac7
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-basic-blocks.ll
@@ -0,0 +1,8 @@
+; RUN: opt -S -passes=canon --rename-all < %s | FileCheck %s
+
+define i32 @foo(i32 %a0) {
+; CHECK: bb{{([0-9]{5})}}
+entry:
+ %a = add i32 %a0, 2
+ ret i32 %a
+}
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-instructions.ll b/llvm/test/Transforms/IRCanonicalizer/naming-instructions.ll
new file mode 100644
index 000000000000000..a22e816f5bf01e9
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-instructions.ll
@@ -0,0 +1,12 @@
+; RUN: opt -S -passes=canon --rename-all < %s | FileCheck %s
+
+define i32 @foo(i32 %a0) {
+entry:
+; CHECK: %"vl{{([0-9]{5})}}(%a0, 2)"
+ %a = add i32 %a0, 2
+; CHECK: %"op{{([0-9]{5})}}(vl{{([0-9]{5})}})"
+ %b = add i32 %a, 6
+; CHECK: %"op{{([0-9]{5})}}(8, op{{([0-9]{5})}}(6, vl{{([0-9]{5})}}(%a0, 2)))"
+ %c = add i32 %b, 8
+ ret i32 %c
+}
diff --git a/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll b/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
new file mode 100644
index 000000000000000..04660ac73c11bd2
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
@@ -0,0 +1,14 @@
+; RUN: opt -S -passes=canon < %s | FileCheck %s
+
+define double @foo(double %a0, double %a1) {
+entry:
+; CHECK: %a
+; CHECK: %c
+; CHECK: %b
+; CHECK: %d
+ %a = fmul double %a0, %a1
+ %b = fmul double %a0, 2.000000e+00
+ %c = fmul double %a, 6.000000e+00
+ %d = fmul double %b, 6.000000e+00
+ ret double %d
+}
diff --git a/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll b/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
new file mode 100644
index 000000000000000..5f344ec29be66f0
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
@@ -0,0 +1,24 @@
+; RUN: opt -S -passes=canon < %s | FileCheck %s
+
+declare double @foo()
+
+declare double @bar()
+
+define double @baz(double %x) {
+entry:
+ %ifcond = fcmp one double %x, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+then: ; preds = %entry
+ %calltmp = call double @foo()
+ br label %ifcont
+
+else: ; preds = %entry
+ %calltmp1 = call double @bar()
+ br label %ifcont
+
+ifcont: ; preds = %else, %then
+; CHECK: %iftmp = phi double [ %calltmp1, %else ], [ %calltmp, %then ]
+ %iftmp = phi double [ %calltmp, %then ], [ %calltmp1, %else ]
+ ret double %iftmp
+}
>From f5b7445662310a2f329e0f4aaf45822058f307ba Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sat, 19 Aug 2023 15:23:09 -0700
Subject: [PATCH 05/14] Turn rename-all and -reorder-operands on by default
---
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 6 ++++--
llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll | 2 +-
.../Transforms/IRCanonicalizer/reordering-instructions.ll | 2 +-
.../IRCanonicalizer/reordering-phi-node-values.ll | 2 +-
4 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index afa3d94e7f55be6..b5a007c80b32b3f 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -95,13 +95,15 @@ cl::opt<bool> IRCanonicalizer::PreserveOrder(
cl::desc("Preserves original instruction order"));
cl::opt<bool> IRCanonicalizer::RenameAll(
"rename-all", cl::Hidden,
- cl::desc("Renames all instructions (including user-named)"));
+ cl::desc("Renames all instructions (including user-named)"),
+ cl::init(true));
cl::opt<bool> IRCanonicalizer::FoldPreoutputs(
"fold-all", cl::Hidden,
cl::desc("Folds all regular instructions (including pre-outputs)"));
cl::opt<bool> IRCanonicalizer::ReorderOperands(
"reorder-operands", cl::Hidden,
- cl::desc("Sorts and reorders operands in commutative instructions"));
+ cl::desc("Sorts and reorders operands in commutative instructions"),
+ cl::init(true));
/// Entry method to the IRCanonicalizer.
///
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll b/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
index b3f7630abd042f1..5a274f7cc5a3b70 100644
--- a/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=canon < %s | FileCheck %s
+; RUN: opt -S -passes=canon --rename-all=false < %s | FileCheck %s
; CHECK: @foo(i32 %a0, i32 %a1)
define i32 @foo(i32, i32) {
diff --git a/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll b/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
index 04660ac73c11bd2..3ea19e8b6c78c97 100644
--- a/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=canon < %s | FileCheck %s
+; RUN: opt -S -passes=canon --rename-all=false < %s | FileCheck %s
define double @foo(double %a0, double %a1) {
entry:
diff --git a/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll b/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
index 5f344ec29be66f0..3ea0bab50b5b9ac 100644
--- a/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=canon < %s | FileCheck %s
+; RUN: opt -S -passes=canon --rename-all=false < %s | FileCheck %s
declare double @foo()
>From 9f93dea7b9d1fb97f947481ac1211da11b897180 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sat, 19 Aug 2023 15:25:12 -0700
Subject: [PATCH 06/14] Add infinite loop regression test
---
.../IRCanonicalizer/infinite-loop.ll | 100 ++++++++++++++++++
1 file changed, 100 insertions(+)
create mode 100644 llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll
diff --git a/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll b/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll
new file mode 100644
index 000000000000000..f67c1eb7fa5b223
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll
@@ -0,0 +1,100 @@
+; RUN: opt -passes=canon < %s
+
+; XFAIL: *
+; FIXME: Infinite loop in name instructions
+
+define void @test(ptr) {
+bb:
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb
+ %tmp = phi i32 [ undef, %bb ], [ %tmp87, %bb1 ]
+ %tmp2 = phi i32 [ undef, %bb ], [ %tmp86, %bb1 ]
+ %tmp3 = mul i32 %tmp, undef
+ %tmp4 = xor i32 %tmp3, -1
+ %tmp5 = add i32 %tmp, %tmp4
+ %tmp6 = add i32 %tmp2, -1
+ %tmp7 = add i32 %tmp5, %tmp6
+ %tmp8 = mul i32 %tmp7, %tmp3
+ %tmp9 = xor i32 %tmp8, -1
+ %tmp10 = add i32 %tmp7, %tmp9
+ %tmp11 = add i32 %tmp10, undef
+ %tmp12 = mul i32 %tmp11, %tmp8
+ %tmp13 = xor i32 %tmp12, -1
+ %tmp14 = add i32 %tmp11, %tmp13
+ %tmp15 = add i32 %tmp14, undef
+ %tmp16 = mul i32 %tmp15, %tmp12
+ %tmp17 = add i32 %tmp15, undef
+ %tmp18 = add i32 %tmp17, undef
+ %tmp19 = mul i32 %tmp18, %tmp16
+ %tmp20 = xor i32 %tmp19, -1
+ %tmp21 = add i32 %tmp18, %tmp20
+ %tmp22 = add i32 %tmp21, undef
+ %tmp23 = mul i32 %tmp22, %tmp19
+ %tmp24 = xor i32 %tmp23, -1
+ %tmp25 = add i32 %tmp22, %tmp24
+ %tmp26 = add i32 %tmp25, undef
+ %tmp27 = mul i32 %tmp26, %tmp23
+ %tmp28 = xor i32 %tmp27, -1
+ %tmp29 = add i32 %tmp26, %tmp28
+ %tmp30 = add i32 %tmp29, undef
+ %tmp31 = mul i32 %tmp30, %tmp27
+ %tmp32 = xor i32 %tmp31, -1
+ %tmp33 = add i32 %tmp30, %tmp32
+ %tmp34 = add i32 %tmp33, undef
+ %tmp35 = mul i32 %tmp34, %tmp31
+ %tmp36 = xor i32 %tmp35, -1
+ %tmp37 = add i32 %tmp34, %tmp36
+ %tmp38 = add i32 %tmp2, -9
+ %tmp39 = add i32 %tmp37, %tmp38
+ %tmp40 = mul i32 %tmp39, %tmp35
+ %tmp41 = xor i32 %tmp40, -1
+ %tmp42 = add i32 %tmp39, %tmp41
+ %tmp43 = add i32 %tmp42, undef
+ %tmp44 = mul i32 %tmp43, %tmp40
+ %tmp45 = xor i32 %tmp44, -1
+ %tmp46 = add i32 %tmp43, %tmp45
+ %tmp47 = add i32 %tmp46, undef
+ %tmp48 = mul i32 %tmp47, %tmp44
+ %tmp49 = xor i32 %tmp48, -1
+ %tmp50 = add i32 %tmp47, %tmp49
+ %tmp51 = add i32 %tmp50, undef
+ %tmp52 = mul i32 %tmp51, %tmp48
+ %tmp53 = xor i32 %tmp52, -1
+ %tmp54 = add i32 %tmp51, %tmp53
+ %tmp55 = add i32 %tmp54, undef
+ %tmp56 = mul i32 %tmp55, %tmp52
+ %tmp57 = xor i32 %tmp56, -1
+ %tmp58 = add i32 %tmp55, %tmp57
+ %tmp59 = add i32 %tmp2, -14
+ %tmp60 = add i32 %tmp58, %tmp59
+ %tmp61 = mul i32 %tmp60, %tmp56
+ %tmp62 = xor i32 %tmp61, -1
+ %tmp63 = add i32 %tmp60, %tmp62
+ %tmp64 = add i32 %tmp63, undef
+ %tmp65 = mul i32 %tmp64, %tmp61
+ %tmp66 = xor i32 %tmp65, -1
+ %tmp67 = add i32 %tmp64, %tmp66
+ %tmp68 = add i32 %tmp67, undef
+ %tmp69 = mul i32 %tmp68, %tmp65
+ %tmp70 = xor i32 %tmp69, -1
+ %tmp71 = add i32 %tmp68, %tmp70
+ %tmp72 = add i32 %tmp71, undef
+ %tmp73 = mul i32 %tmp72, %tmp69
+ %tmp74 = xor i32 %tmp73, -1
+ %tmp75 = add i32 %tmp72, %tmp74
+ %tmp76 = add i32 %tmp75, undef
+ %tmp77 = mul i32 %tmp76, %tmp73
+ %tmp78 = xor i32 %tmp77, -1
+ %tmp79 = add i32 %tmp76, %tmp78
+ %tmp80 = add i32 %tmp79, undef
+ %tmp81 = mul i32 %tmp80, %tmp77
+ %tmp82 = xor i32 %tmp81, -1
+ %tmp83 = add i32 %tmp80, %tmp82
+ %tmp84 = add i32 %tmp83, undef
+ %tmp85 = add i32 %tmp84, undef
+ %tmp86 = add i32 %tmp2, -21
+ %tmp87 = add i32 %tmp85, %tmp86
+ store i32 %tmp87, ptr %0
+ br label %bb1
+}
>From 23a379fc765a86c35b7b9682a66199fdaa1b830f Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sun, 27 Aug 2023 15:19:36 -0700
Subject: [PATCH 07/14] Add visited set to fix infinite loop bug
---
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index b5a007c80b32b3f..73433a9a05c0d4e 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -57,6 +57,7 @@ class IRCanonicalizer {
private:
// Random constant for hashing, so the state isn't zero.
const uint64_t MagicHashConstant = 0x6acaa36bef8325c5ULL;
+ DenseSet<const Instruction *> NamedInstructions;
/// \name Naming.
/// @{
@@ -175,6 +176,9 @@ void IRCanonicalizer::nameBasicBlocks(Function &F) {
///
/// \param I Instruction to be renamed.
void IRCanonicalizer::nameInstruction(Instruction *I) {
+ if (NamedInstructions.contains(I))
+ return;
+ NamedInstructions.insert(I);
// Determine the type of instruction to name.
if (isInitialInstruction(I)) {
// This is an initial instruction.
>From 560abe4f953f75a89e7a0407ff09ea866664a2fd Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Sun, 27 Aug 2023 15:20:12 -0700
Subject: [PATCH 08/14] Expand test to expose reordering bug
---
.../Transforms/IRCanonicalizer/infinite-loop.ll | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll b/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll
index f67c1eb7fa5b223..3438a05b4aee489 100644
--- a/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/infinite-loop.ll
@@ -1,15 +1,14 @@
-; RUN: opt -passes=canon < %s
+; RUN: opt -passes=canon -preserve-order=true < %s
+; RUN: opt -passes=canon -preserve-order=false < %s
-; XFAIL: *
-; FIXME: Infinite loop in name instructions
-
-define void @test(ptr) {
+define void @test(ptr, i32) {
bb:
+ %a = add i32 %1, 1
br label %bb1
bb1: ; preds = %bb1, %bb
- %tmp = phi i32 [ undef, %bb ], [ %tmp87, %bb1 ]
- %tmp2 = phi i32 [ undef, %bb ], [ %tmp86, %bb1 ]
+ %tmp = phi i32 [ %a, %bb ], [ %tmp87, %bb1 ]
+ %tmp2 = phi i32 [ %a, %bb ], [ %tmp86, %bb1 ]
%tmp3 = mul i32 %tmp, undef
%tmp4 = xor i32 %tmp3, -1
%tmp5 = add i32 %tmp, %tmp4
>From 3aaecbddf6a45ba23a32706ac99c8e6e963c924b Mon Sep 17 00:00:00 2001
From: Aidan <aidan.goldfarb at mail.mcgill.ca>
Date: Mon, 28 Aug 2023 12:28:20 -0400
Subject: [PATCH 09/14] added some documentation
---
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 3 +++
1 file changed, 3 insertions(+)
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index 73433a9a05c0d4e..600c2baf6e013a5 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -176,6 +176,9 @@ void IRCanonicalizer::nameBasicBlocks(Function &F) {
///
/// \param I Instruction to be renamed.
void IRCanonicalizer::nameInstruction(Instruction *I) {
+ //ensure instructions are not renamed. This is done
+ //to prevent situation where instructions are used
+ //before their definition (in phi nodes)
if (NamedInstructions.contains(I))
return;
NamedInstructions.insert(I);
>From 2111bf1e6a27c553990528abee3a9fa2c2390bdd Mon Sep 17 00:00:00 2001
From: Aidan <aidan.goldfarb at mail.mcgill.ca>
Date: Mon, 28 Aug 2023 13:56:05 -0400
Subject: [PATCH 10/14] pushed broken int test
---
.../IRCanonicalizer/naming-args-instr-blocks.ll | 15 +++++++++++++++
1 file changed, 15 insertions(+)
create mode 100644 llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll b/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll
new file mode 100644
index 000000000000000..74e1944825011b0
--- /dev/null
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll
@@ -0,0 +1,15 @@
+; RUN: opt -S -passes=canon --rename-all --preserve-order < %s | FileCheck %s
+
+
+; CHECK: @foo(i32 %a0)
+define i32 @foo(i32) {
+; CHECK: bb{{([0-9]{5})}}
+entry:
+ ; CHECK: %"vl{{([0-9]{5})}}(%a0, 2)"
+ %a = add i32 %0, 2
+
+ ; CHECK: %"op{{([0-9]{5})}}(vl{{([0-9]{5})}})"
+ %b = add i32 %a, 6
+
+ ret i32 %a
+}
>From 1db7ecbc4a461295f7cdf04488b94984803a3e60 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Mon, 11 Sep 2023 12:27:35 -0700
Subject: [PATCH 11/14] Reformat `reorderInstruction`
---
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 30 +++++++++----------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index 600c2baf6e013a5..6f60d3d261d8286 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -443,23 +443,23 @@ void IRCanonicalizer::reorderInstructions(
void IRCanonicalizer::reorderInstruction(
Instruction *Used, Instruction *User,
SmallPtrSet<const Instruction *, 32> &Visited) {
+ if (Visited.contains(Used)) {
+ return;
+ }
+ Visited.insert(Used);
- if (!Visited.count(Used)) {
- Visited.insert(Used);
-
- if (Used->getParent() == User->getParent()) {
- // If Used and User share the same basic block move Used just before User.
- Used->moveBefore(User);
- } else {
- // Otherwise move Used to the very end of its basic block.
- Used->moveBefore(&Used->getParent()->back());
- }
+ if (Used->getParent() == User->getParent()) {
+ // If Used and User share the same basic block move Used just before User.
+ Used->moveBefore(User);
+ } else {
+ // Otherwise move Used to the very end of its basic block.
+ Used->moveBefore(&Used->getParent()->back());
+ }
- for (auto &OP : Used->operands()) {
- if (auto *IOP = dyn_cast<Instruction>(OP)) {
- // Walk up the def-use tree.
- reorderInstruction(IOP, Used, Visited);
- }
+ for (auto &OP : Used->operands()) {
+ if (auto *IOP = dyn_cast<Instruction>(OP)) {
+ // Walk up the def-use tree.
+ reorderInstruction(IOP, Used, Visited);
}
}
}
>From 2debd15624fe9b69840551288bec734e8ef2ea75 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Mon, 11 Sep 2023 13:05:30 -0700
Subject: [PATCH 12/14] Bug fix: don't reorder PHI nodes
---
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index 6f60d3d261d8286..a40435f7b822932 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -443,9 +443,10 @@ void IRCanonicalizer::reorderInstructions(
void IRCanonicalizer::reorderInstruction(
Instruction *Used, Instruction *User,
SmallPtrSet<const Instruction *, 32> &Visited) {
- if (Visited.contains(Used)) {
+ if(isa<PHINode>(Used))
+ return;
+ if (Visited.contains(Used))
return;
- }
Visited.insert(Used);
if (Used->getParent() == User->getParent()) {
>From 8a05e501b94aa50a9802c4df5398dd5a0805572f Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Mon, 11 Sep 2023 13:29:27 -0700
Subject: [PATCH 13/14] Revert "Turn rename-all and -reorder-operands on by
default"
This reverts commit f5b7445662310a2f329e0f4aaf45822058f307ba.
---
llvm/lib/Transforms/Utils/IRCanonicalizer.cpp | 6 ++----
llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll | 2 +-
.../Transforms/IRCanonicalizer/reordering-instructions.ll | 2 +-
.../IRCanonicalizer/reordering-phi-node-values.ll | 2 +-
4 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
index a40435f7b822932..45dc954f97b9c7e 100644
--- a/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
+++ b/llvm/lib/Transforms/Utils/IRCanonicalizer.cpp
@@ -96,15 +96,13 @@ cl::opt<bool> IRCanonicalizer::PreserveOrder(
cl::desc("Preserves original instruction order"));
cl::opt<bool> IRCanonicalizer::RenameAll(
"rename-all", cl::Hidden,
- cl::desc("Renames all instructions (including user-named)"),
- cl::init(true));
+ cl::desc("Renames all instructions (including user-named)"));
cl::opt<bool> IRCanonicalizer::FoldPreoutputs(
"fold-all", cl::Hidden,
cl::desc("Folds all regular instructions (including pre-outputs)"));
cl::opt<bool> IRCanonicalizer::ReorderOperands(
"reorder-operands", cl::Hidden,
- cl::desc("Sorts and reorders operands in commutative instructions"),
- cl::init(true));
+ cl::desc("Sorts and reorders operands in commutative instructions"));
/// Entry method to the IRCanonicalizer.
///
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll b/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
index 5a274f7cc5a3b70..b3f7630abd042f1 100644
--- a/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-arguments.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=canon --rename-all=false < %s | FileCheck %s
+; RUN: opt -S -passes=canon < %s | FileCheck %s
; CHECK: @foo(i32 %a0, i32 %a1)
define i32 @foo(i32, i32) {
diff --git a/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll b/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
index 3ea19e8b6c78c97..04660ac73c11bd2 100644
--- a/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/reordering-instructions.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=canon --rename-all=false < %s | FileCheck %s
+; RUN: opt -S -passes=canon < %s | FileCheck %s
define double @foo(double %a0, double %a1) {
entry:
diff --git a/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll b/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
index 3ea0bab50b5b9ac..5f344ec29be66f0 100644
--- a/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/reordering-phi-node-values.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=canon --rename-all=false < %s | FileCheck %s
+; RUN: opt -S -passes=canon < %s | FileCheck %s
declare double @foo()
>From fa6159c30002c530f40b41380ed2b64294543c01 Mon Sep 17 00:00:00 2001
From: justinfargnoli <justinfargnoli at gmail.com>
Date: Mon, 25 Sep 2023 11:13:25 -0500
Subject: [PATCH 14/14] Fix naming-args-instr-blocks.ll
---
.../Transforms/IRCanonicalizer/naming-args-instr-blocks.ll | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll b/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll
index 74e1944825011b0..605c62863f2ad38 100644
--- a/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll
+++ b/llvm/test/Transforms/IRCanonicalizer/naming-args-instr-blocks.ll
@@ -8,8 +8,8 @@ entry:
; CHECK: %"vl{{([0-9]{5})}}(%a0, 2)"
%a = add i32 %0, 2
- ; CHECK: %"op{{([0-9]{5})}}(vl{{([0-9]{5})}})"
+ ; CHECK: %"op{{([0-9]{5})}}(6, vl{{([0-9]{5})}}(%a0, 2))"
%b = add i32 %a, 6
- ret i32 %a
+ ret i32 %b
}
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