As Chris and Evan pointed out, BreakCriticalMachineEdges doesn't really need
to be a pass of its own. Instead, move it out into a helper method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44002 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BreakCriticalMachineEdges.cpp b/lib/CodeGen/BreakCriticalMachineEdges.cpp
deleted file mode 100644
index 21d9dbb..0000000
--- a/lib/CodeGen/BreakCriticalMachineEdges.cpp
+++ /dev/null
@@ -1,131 +0,0 @@
-//===----------- BreakCriticalMachineEdges - Break critical edges ---------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file was developed by Fernando Pereira and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
-//===---------------------------------------------------------------------===//
-//
-// Break all of the critical edges in the CFG by inserting a dummy basic block.
-// This pass may be "required" by passes that cannot deal with critical edges.
-// Notice that this pass invalidates the CFG, because the same BasicBlock is
-// used as parameter for the src MachineBasicBlock and the new dummy
-// MachineBasicBlock.
-//
-//===---------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineJumpTableInfo.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Support/Compiler.h"
-
-using namespace llvm;
-
-namespace {
- struct VISIBILITY_HIDDEN BreakCriticalMachineEdges :
- public MachineFunctionPass {
- static char ID; // Pass identification
- BreakCriticalMachineEdges() : MachineFunctionPass((intptr_t)&ID) {}
-
- bool runOnMachineFunction(MachineFunction& Fn);
- void splitCriticalEdge(MachineBasicBlock* A, MachineBasicBlock* B);
- };
-
- char BreakCriticalMachineEdges::ID = 0;
- RegisterPass<BreakCriticalMachineEdges> X("critical-machine-edges",
- "Break critical machine code edges");
-}
-
-const PassInfo *llvm::BreakCriticalMachineEdgesID = X.getPassInfo();
-
-void BreakCriticalMachineEdges::splitCriticalEdge(MachineBasicBlock* src,
- MachineBasicBlock* dst) {
- const BasicBlock* srcBB = src->getBasicBlock();
-
- MachineBasicBlock* crit_mbb = new MachineBasicBlock(srcBB);
-
- // modify the llvm control flow graph
- src->removeSuccessor(dst);
- src->addSuccessor(crit_mbb);
- crit_mbb->addSuccessor(dst);
-
- // insert the new block into the machine function.
- src->getParent()->getBasicBlockList().insert(src->getParent()->end(),
- crit_mbb);
-
- // insert a unconditional branch linking the new block to dst
- const TargetMachine& TM = src->getParent()->getTarget();
- const TargetInstrInfo* TII = TM.getInstrInfo();
- std::vector<MachineOperand> emptyConditions;
- TII->InsertBranch(*crit_mbb, dst, (MachineBasicBlock*)0, emptyConditions);
-
- // modify every branch in src that points to dst to point to the new
- // machine basic block instead:
- MachineBasicBlock::iterator mii = src->end();
- bool found_branch = false;
- while (mii != src->begin()) {
- mii--;
- // if there are no more branches, finish the loop
- if (!TII->isTerminatorInstr(mii->getOpcode())) {
- break;
- }
-
- // Scan the operands of this branch, replacing any uses of dst with
- // crit_mbb.
- for (unsigned i = 0, e = mii->getNumOperands(); i != e; ++i) {
- MachineOperand & mo = mii->getOperand(i);
- if (mo.isMachineBasicBlock() &&
- mo.getMachineBasicBlock() == dst) {
- found_branch = true;
- mo.setMachineBasicBlock(crit_mbb);
- }
- }
- }
-
- // TODO: This is tentative. It may be necessary to fix this code. Maybe
- // I am inserting too many gotos, but I am trusting that the asm printer
- // will optimize the unnecessary gotos.
- if(!found_branch) {
- TII->InsertBranch(*src, crit_mbb, (MachineBasicBlock*)0, emptyConditions);
- }
-
- /// Change all the phi functions in dst, so that the incoming block be
- /// crit_mbb, instead of src
- for(mii = dst->begin(); mii != dst->end(); mii++) {
- /// the first instructions are always phi functions.
- if(mii->getOpcode() != TargetInstrInfo::PHI)
- break;
-
- for (unsigned u = 0; u != mii->getNumOperands(); ++u)
- if (mii->getOperand(u).isMachineBasicBlock() &&
- mii->getOperand(u).getMachineBasicBlock() == src)
- mii->getOperand(u).setMachineBasicBlock(crit_mbb);
- }
-}
-
-bool BreakCriticalMachineEdges::runOnMachineFunction(MachineFunction& F) {
- std::vector<MachineBasicBlock *> SourceBlocks;
- std::vector<MachineBasicBlock *> DestBlocks;
-
- for(MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
- for(MachineBasicBlock::succ_iterator SI = FI->succ_begin(),
- SE = FI->succ_end(); SI != SE; ++SI) {
- // predecessor with multiple successors, successor with multiple
- // predecessors.
- if (FI->succ_size() > 1 && (*SI)->pred_size() > 1) {
- SourceBlocks.push_back(FI);
- DestBlocks.push_back(*SI);
- }
- }
- }
-
- for(unsigned u = 0; u < SourceBlocks.size(); u++)
- splitCriticalEdge(SourceBlocks[u], DestBlocks[u]);
-
- return false;
-}
diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index 5f84b58..f64186e 100644
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -21,6 +21,7 @@
#define DEBUG_TYPE "strongphielim"
#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/BreakCriticalMachineEdge.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index defd6ce..b8d38dc 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -70,7 +70,6 @@
AU.addRequired<LiveVariables>();
AU.addPreserved<LiveVariables>();
AU.addPreservedID(PHIEliminationID);
- AU.addPreservedID(BreakCriticalMachineEdgesID);
MachineFunctionPass::getAnalysisUsage(AU);
}