From 143976480286b42c20195ff4324c1703e904a149 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Thu, 10 Apr 2025 14:45:14 -0300 Subject: [PATCH 01/14] [CodeGen][NPM] Create method to add the branch folding pass with the option to enable tail merge Signed-off-by: Mikhail R. Gadelha --- llvm/include/llvm/CodeGen/Passes.h | 2 ++ llvm/lib/CodeGen/BranchFolding.cpp | 12 ++++++++++-- llvm/lib/Target/RISCV/RISCVTargetMachine.cpp | 1 + 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/llvm/include/llvm/CodeGen/Passes.h b/llvm/include/llvm/CodeGen/Passes.h index d214ab9306c2f..426e430b947f9 100644 --- a/llvm/include/llvm/CodeGen/Passes.h +++ b/llvm/include/llvm/CodeGen/Passes.h @@ -257,6 +257,8 @@ namespace llvm { /// branches. extern char &BranchFolderPassID; + MachineFunctionPass *createBranchFolderPass(bool EnableTailMerge); + /// BranchRelaxation - This pass replaces branches that need to jump further /// than is supported by a branch instruction. extern char &BranchRelaxationPassID; diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 6f5afbd2a996a..5d015d7313b5c 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -90,10 +90,13 @@ namespace { /// BranchFolderPass - Wrap branch folder in a machine function pass. class BranchFolderLegacy : public MachineFunctionPass { + bool EnableTailMerge; + public: static char ID; - explicit BranchFolderLegacy() : MachineFunctionPass(ID) {} + explicit BranchFolderLegacy(bool EnableTailMerge = true) + : MachineFunctionPass(ID), EnableTailMerge(EnableTailMerge) {} bool runOnMachineFunction(MachineFunction &MF) override; @@ -152,7 +155,8 @@ bool BranchFolderLegacy::runOnMachineFunction(MachineFunction &MF) { // TailMerge can create jump into if branches that make CFG irreducible for // HW that requires structurized CFG. bool EnableTailMerge = !MF.getTarget().requiresStructuredCFG() && - PassConfig->getEnableTailMerge(); + PassConfig->getEnableTailMerge() && + this->EnableTailMerge; MBFIWrapper MBBFreqInfo( getAnalysis().getMBFI()); BranchFolder Folder( @@ -2080,3 +2084,7 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) { ++NumHoist; return true; } + +MachineFunctionPass *llvm::createBranchFolderPass(bool EnableTailMerge = true) { + return new BranchFolderLegacy(EnableTailMerge); +} diff --git a/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp b/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp index 7fb64be3975d5..8ff5e02f1d767 100644 --- a/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp +++ b/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp @@ -18,6 +18,7 @@ #include "RISCVTargetTransformInfo.h" #include "TargetInfo/RISCVTargetInfo.h" #include "llvm/Analysis/TargetTransformInfo.h" +#include "llvm/CodeGen/BranchFoldingPass.h" #include "llvm/CodeGen/GlobalISel/CSEInfo.h" #include "llvm/CodeGen/GlobalISel/IRTranslator.h" #include "llvm/CodeGen/GlobalISel/InstructionSelect.h" From 1129f40a6120a978cdd5161a410e27ecbe536367 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Thu, 10 Apr 2025 17:16:50 -0300 Subject: [PATCH 02/14] Add printPipeline Signed-off-by: Mikhail R. Gadelha --- llvm/include/llvm/CodeGen/BranchFoldingPass.h | 3 +++ llvm/lib/CodeGen/BranchFolding.cpp | 7 +++++++ 2 files changed, 10 insertions(+) diff --git a/llvm/include/llvm/CodeGen/BranchFoldingPass.h b/llvm/include/llvm/CodeGen/BranchFoldingPass.h index 6ebef47252d25..b4380b5a4a6c8 100644 --- a/llvm/include/llvm/CodeGen/BranchFoldingPass.h +++ b/llvm/include/llvm/CodeGen/BranchFoldingPass.h @@ -24,6 +24,9 @@ class BranchFolderPass : public PassInfoMixin { return MachineFunctionProperties().set( MachineFunctionProperties::Property::NoPHIs); } + + void printPipeline(raw_ostream &OS, + function_ref MapClassName2PassName); }; } // namespace llvm diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 5d015d7313b5c..42f54c2526487 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -147,6 +147,13 @@ PreservedAnalyses BranchFolderPass::run(MachineFunction &MF, return getMachineFunctionPassPreservedAnalyses(); } +void BranchFolderPass::printPipeline( + raw_ostream &OS, function_ref MapClassName2PassName) { + OS << MapClassName2PassName(name()); + if (EnableTailMerge) + OS << ""; +} + bool BranchFolderLegacy::runOnMachineFunction(MachineFunction &MF) { if (skipFunction(MF.getFunction())) return false; From 7d8d9df2dd494cfe0886f5c9962972ea92cb7006 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Thu, 10 Apr 2025 17:48:08 -0300 Subject: [PATCH 03/14] Remove unused include Signed-off-by: Mikhail R. Gadelha --- llvm/lib/Target/RISCV/RISCVTargetMachine.cpp | 1 - 1 file changed, 1 deletion(-) diff --git a/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp b/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp index 8ff5e02f1d767..7fb64be3975d5 100644 --- a/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp +++ b/llvm/lib/Target/RISCV/RISCVTargetMachine.cpp @@ -18,7 +18,6 @@ #include "RISCVTargetTransformInfo.h" #include "TargetInfo/RISCVTargetInfo.h" #include "llvm/Analysis/TargetTransformInfo.h" -#include "llvm/CodeGen/BranchFoldingPass.h" #include "llvm/CodeGen/GlobalISel/CSEInfo.h" #include "llvm/CodeGen/GlobalISel/IRTranslator.h" #include "llvm/CodeGen/GlobalISel/InstructionSelect.h" From 9b959746c3125f3f8727158cb26151b666ff6772 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Fri, 11 Apr 2025 12:05:16 -0300 Subject: [PATCH 04/14] Pass global flag via argument Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/BranchFolding.cpp | 5 ++--- llvm/lib/CodeGen/TargetPassConfig.cpp | 2 +- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 42f54c2526487..38a4ff604f55a 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -161,9 +161,8 @@ bool BranchFolderLegacy::runOnMachineFunction(MachineFunction &MF) { TargetPassConfig *PassConfig = &getAnalysis(); // TailMerge can create jump into if branches that make CFG irreducible for // HW that requires structurized CFG. - bool EnableTailMerge = !MF.getTarget().requiresStructuredCFG() && - PassConfig->getEnableTailMerge() && - this->EnableTailMerge; + bool EnableTailMerge = + !MF.getTarget().requiresStructuredCFG() && this->EnableTailMerge; MBFIWrapper MBBFreqInfo( getAnalysis().getMBFI()); BranchFolder Folder( diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index fa1bb84ec5319..ec9012e99107b 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -1514,7 +1514,7 @@ void TargetPassConfig::addMachineLateOptimization() { addPass(&MachineLateInstrsCleanupID); // Branch folding must be run after regalloc and prolog/epilog insertion. - addPass(&BranchFolderPassID); + addPass(createBranchFolderPass(getEnableTailMerge())); // Tail duplication. // Note that duplicating tail just increases code size and degrades From 17fcc45152e17ac5f95bc8d6bd2ba63f31787484 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Fri, 11 Apr 2025 12:15:56 -0300 Subject: [PATCH 05/14] Removed the default arg Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/BranchFolding.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 38a4ff604f55a..97c5a5b017883 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -95,7 +95,7 @@ class BranchFolderLegacy : public MachineFunctionPass { public: static char ID; - explicit BranchFolderLegacy(bool EnableTailMerge = true) + explicit BranchFolderLegacy(bool EnableTailMerge) : MachineFunctionPass(ID), EnableTailMerge(EnableTailMerge) {} bool runOnMachineFunction(MachineFunction &MF) override; @@ -2091,6 +2091,6 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) { return true; } -MachineFunctionPass *llvm::createBranchFolderPass(bool EnableTailMerge = true) { +MachineFunctionPass *llvm::createBranchFolderPass(bool EnableTailMerge) { return new BranchFolderLegacy(EnableTailMerge); } From 73b228a47dd23fe7ea42e3d83926814cf3e4253a Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Fri, 11 Apr 2025 13:05:50 -0300 Subject: [PATCH 06/14] PassConfig is no longer needed Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/BranchFolding.cpp | 3 --- 1 file changed, 3 deletions(-) diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 97c5a5b017883..90385a8d6a7a5 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -39,7 +39,6 @@ #include "llvm/CodeGen/MachineSizeOpts.h" #include "llvm/CodeGen/TargetInstrInfo.h" #include "llvm/CodeGen/TargetOpcodes.h" -#include "llvm/CodeGen/TargetPassConfig.h" #include "llvm/CodeGen/TargetRegisterInfo.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/IR/DebugInfoMetadata.h" @@ -104,7 +103,6 @@ class BranchFolderLegacy : public MachineFunctionPass { AU.addRequired(); AU.addRequired(); AU.addRequired(); - AU.addRequired(); MachineFunctionPass::getAnalysisUsage(AU); } @@ -158,7 +156,6 @@ bool BranchFolderLegacy::runOnMachineFunction(MachineFunction &MF) { if (skipFunction(MF.getFunction())) return false; - TargetPassConfig *PassConfig = &getAnalysis(); // TailMerge can create jump into if branches that make CFG irreducible for // HW that requires structurized CFG. bool EnableTailMerge = From f2dd02c4c56d11d6d166f149594c38ddbc68c49b Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Mon, 14 Apr 2025 19:20:52 -0300 Subject: [PATCH 07/14] Implemented suggested changes Signed-off-by: Mikhail R. Gadelha --- llvm/include/llvm/CodeGen/TargetPassConfig.h | 2 +- llvm/lib/CodeGen/TargetPassConfig.cpp | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/llvm/include/llvm/CodeGen/TargetPassConfig.h b/llvm/include/llvm/CodeGen/TargetPassConfig.h index 1af7267fa9ecf..c3fc31243c51a 100644 --- a/llvm/include/llvm/CodeGen/TargetPassConfig.h +++ b/llvm/include/llvm/CodeGen/TargetPassConfig.h @@ -457,7 +457,7 @@ class TargetPassConfig : public ImmutablePass { /// Add a CodeGen pass at this point in the pipeline after checking overrides. /// Return the pass that was added, or zero if no pass was added. - AnalysisID addPass(AnalysisID PassID); + AnalysisID addPass(IdentifyingPassPtr PassID); /// Add a pass to the PassManager if that pass is supposed to be run, as /// determined by the StartAfter and StopAfter options. Takes ownership of the diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index ec9012e99107b..649e76bb84828 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -745,7 +745,9 @@ void TargetPassConfig::addPass(Pass *P) { /// /// addPass cannot return a pointer to the pass instance because is internal the /// PassManager and the instance we create here may already be freed. -AnalysisID TargetPassConfig::addPass(AnalysisID PassID) { +AnalysisID TargetPassConfig::addPass(IdentifyingPassPtr PassPtr) { + AnalysisID PassID = PassPtr.isInstance() ? PassPtr.getInstance()->getPassID() + : PassPtr.getID(); IdentifyingPassPtr TargetID = getPassSubstitution(PassID); IdentifyingPassPtr FinalPtr = overridePass(PassID, TargetID); if (!FinalPtr.isValid()) @@ -1513,8 +1515,7 @@ void TargetPassConfig::addMachineLateOptimization() { // Cleanup of redundant immediate/address loads. addPass(&MachineLateInstrsCleanupID); - // Branch folding must be run after regalloc and prolog/epilog insertion. - addPass(createBranchFolderPass(getEnableTailMerge())); + addPass(IdentifyingPassPtr(createBranchFolderPass(getEnableTailMerge()))); // Tail duplication. // Note that duplicating tail just increases code size and degrades From fc156b55783ea05e0285ef9348ab00f4e300fad5 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Tue, 15 Apr 2025 09:51:06 -0300 Subject: [PATCH 08/14] Default to true Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/BranchFolding.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 90385a8d6a7a5..b54881dd95f6b 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -94,7 +94,7 @@ class BranchFolderLegacy : public MachineFunctionPass { public: static char ID; - explicit BranchFolderLegacy(bool EnableTailMerge) + explicit BranchFolderLegacy(bool EnableTailMerge = true) : MachineFunctionPass(ID), EnableTailMerge(EnableTailMerge) {} bool runOnMachineFunction(MachineFunction &MF) override; @@ -2088,6 +2088,6 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) { return true; } -MachineFunctionPass *llvm::createBranchFolderPass(bool EnableTailMerge) { +MachineFunctionPass *llvm::createBranchFolderPass(bool EnableTailMerge = true) { return new BranchFolderLegacy(EnableTailMerge); } From b49d6d36cd84498112001dccc74ff122bf503532 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Tue, 15 Apr 2025 15:12:24 -0300 Subject: [PATCH 09/14] Revert "Implemented suggested changes" This reverts commit f2dd02c4c56d11d6d166f149594c38ddbc68c49b. --- llvm/include/llvm/CodeGen/TargetPassConfig.h | 2 +- llvm/lib/CodeGen/TargetPassConfig.cpp | 7 +++---- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/llvm/include/llvm/CodeGen/TargetPassConfig.h b/llvm/include/llvm/CodeGen/TargetPassConfig.h index c3fc31243c51a..1af7267fa9ecf 100644 --- a/llvm/include/llvm/CodeGen/TargetPassConfig.h +++ b/llvm/include/llvm/CodeGen/TargetPassConfig.h @@ -457,7 +457,7 @@ class TargetPassConfig : public ImmutablePass { /// Add a CodeGen pass at this point in the pipeline after checking overrides. /// Return the pass that was added, or zero if no pass was added. - AnalysisID addPass(IdentifyingPassPtr PassID); + AnalysisID addPass(AnalysisID PassID); /// Add a pass to the PassManager if that pass is supposed to be run, as /// determined by the StartAfter and StopAfter options. Takes ownership of the diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index 649e76bb84828..ec9012e99107b 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -745,9 +745,7 @@ void TargetPassConfig::addPass(Pass *P) { /// /// addPass cannot return a pointer to the pass instance because is internal the /// PassManager and the instance we create here may already be freed. -AnalysisID TargetPassConfig::addPass(IdentifyingPassPtr PassPtr) { - AnalysisID PassID = PassPtr.isInstance() ? PassPtr.getInstance()->getPassID() - : PassPtr.getID(); +AnalysisID TargetPassConfig::addPass(AnalysisID PassID) { IdentifyingPassPtr TargetID = getPassSubstitution(PassID); IdentifyingPassPtr FinalPtr = overridePass(PassID, TargetID); if (!FinalPtr.isValid()) @@ -1515,7 +1513,8 @@ void TargetPassConfig::addMachineLateOptimization() { // Cleanup of redundant immediate/address loads. addPass(&MachineLateInstrsCleanupID); - addPass(IdentifyingPassPtr(createBranchFolderPass(getEnableTailMerge()))); + // Branch folding must be run after regalloc and prolog/epilog insertion. + addPass(createBranchFolderPass(getEnableTailMerge())); // Tail duplication. // Note that duplicating tail just increases code size and degrades From 129347733db518861cd36aa0a293334f4185ddcb Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Tue, 15 Apr 2025 15:29:07 -0300 Subject: [PATCH 10/14] Check if the pass was disabled when adding the pass via the pass' pointer Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/TargetPassConfig.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index ec9012e99107b..8de3ff808f083 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -707,6 +707,10 @@ void TargetPassConfig::addPass(Pass *P) { // and shouldn't reference it. AnalysisID PassID = P->getPassID(); + IdentifyingPassPtr TargetID = getPassSubstitution(PassID); + if (!overridePass(PassID, TargetID).isValid()) + return; + if (StartBefore == PassID && StartBeforeCount++ == StartBeforeInstanceNum) Started = true; if (StopBefore == PassID && StopBeforeCount++ == StopBeforeInstanceNum) From 756e1a5ce9035d3637d8f3081202fada172e5e37 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Fri, 18 Apr 2025 14:27:54 -0300 Subject: [PATCH 11/14] Moved requiresStructuredCFG check to pass creation Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/BranchFolding.cpp | 3 --- llvm/lib/CodeGen/TargetPassConfig.cpp | 3 ++- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index b54881dd95f6b..43b8a6a583a29 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -124,9 +124,6 @@ INITIALIZE_PASS(BranchFolderLegacy, DEBUG_TYPE, "Control Flow Optimizer", false, PreservedAnalyses BranchFolderPass::run(MachineFunction &MF, MachineFunctionAnalysisManager &MFAM) { MFPropsModifier _(*this, MF); - bool EnableTailMerge = - !MF.getTarget().requiresStructuredCFG() && this->EnableTailMerge; - auto &MBPI = MFAM.getResult(MF); auto *PSI = MFAM.getResult(MF) .getCachedResult( diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index 8de3ff808f083..a8e676ad54b22 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -1518,7 +1518,8 @@ void TargetPassConfig::addMachineLateOptimization() { addPass(&MachineLateInstrsCleanupID); // Branch folding must be run after regalloc and prolog/epilog insertion. - addPass(createBranchFolderPass(getEnableTailMerge())); + addPass(createBranchFolderPass(!TM->requiresStructuredCFG() && + getEnableTailMerge())); // Tail duplication. // Note that duplicating tail just increases code size and degrades From 501a1cf70188cb6b55586a505b5b926812cecd5c Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Mon, 21 Apr 2025 09:53:11 -0300 Subject: [PATCH 12/14] Use isPassSubstitutedOrOverridden to check if the pass was disabled Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/TargetPassConfig.cpp | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index a8e676ad54b22..4a5469b6d47ad 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -707,10 +707,6 @@ void TargetPassConfig::addPass(Pass *P) { // and shouldn't reference it. AnalysisID PassID = P->getPassID(); - IdentifyingPassPtr TargetID = getPassSubstitution(PassID); - if (!overridePass(PassID, TargetID).isValid()) - return; - if (StartBefore == PassID && StartBeforeCount++ == StartBeforeInstanceNum) Started = true; if (StopBefore == PassID && StopBeforeCount++ == StopBeforeInstanceNum) @@ -1518,8 +1514,9 @@ void TargetPassConfig::addMachineLateOptimization() { addPass(&MachineLateInstrsCleanupID); // Branch folding must be run after regalloc and prolog/epilog insertion. - addPass(createBranchFolderPass(!TM->requiresStructuredCFG() && - getEnableTailMerge())); + if(!isPassSubstitutedOrOverridden(&BranchFolderPassID)) + addPass(createBranchFolderPass(!TM->requiresStructuredCFG() && + getEnableTailMerge())); // Tail duplication. // Note that duplicating tail just increases code size and degrades From 61251d309508ad9de53cd734c50e886718c83c10 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Mon, 21 Apr 2025 09:57:17 -0300 Subject: [PATCH 13/14] Removed unnecessary local variable Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/BranchFolding.cpp | 4 ---- 1 file changed, 4 deletions(-) diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 43b8a6a583a29..ad4ab3142d542 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -153,10 +153,6 @@ bool BranchFolderLegacy::runOnMachineFunction(MachineFunction &MF) { if (skipFunction(MF.getFunction())) return false; - // TailMerge can create jump into if branches that make CFG irreducible for - // HW that requires structurized CFG. - bool EnableTailMerge = - !MF.getTarget().requiresStructuredCFG() && this->EnableTailMerge; MBFIWrapper MBBFreqInfo( getAnalysis().getMBFI()); BranchFolder Folder( From ec4571a7ca8271d6cd4f137399fdaffe6250a7e0 Mon Sep 17 00:00:00 2001 From: "Mikhail R. Gadelha" Date: Mon, 21 Apr 2025 10:14:16 -0300 Subject: [PATCH 14/14] clang-format Signed-off-by: Mikhail R. Gadelha --- llvm/lib/CodeGen/TargetPassConfig.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp index 4a5469b6d47ad..99caf31736baf 100644 --- a/llvm/lib/CodeGen/TargetPassConfig.cpp +++ b/llvm/lib/CodeGen/TargetPassConfig.cpp @@ -1514,9 +1514,9 @@ void TargetPassConfig::addMachineLateOptimization() { addPass(&MachineLateInstrsCleanupID); // Branch folding must be run after regalloc and prolog/epilog insertion. - if(!isPassSubstitutedOrOverridden(&BranchFolderPassID)) + if (!isPassSubstitutedOrOverridden(&BranchFolderPassID)) addPass(createBranchFolderPass(!TM->requiresStructuredCFG() && - getEnableTailMerge())); + getEnableTailMerge())); // Tail duplication. // Note that duplicating tail just increases code size and degrades