6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-13 09:33:50 +00:00
Code Issues Projects Releases Wiki Activity

More cleanups. Also, add a special case for updating PHI nodes, and

Browse Source 
reimplement getValueDominatingFunction to walk the DominanceTree rather than
just searching blindly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28618 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2006-06-01 06:05:47 +00:00
parent 2675534b7f
commit 2824da4738
1 changed files with 33 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
lib/Transforms/Utils/LCSSA.cpp
View File

@ -36,7 +36,7 @@
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Support/CFG.h"
#include <algorithm>
#include <iostream>
#include <cassert>
#include <map>
#include <vector>
@ -143,17 +143,12 @@ void LCSSA::processInstruction(Instruction* Instr,
std::vector<PHINode*> workList;
for (std::vector<BasicBlock*>::const_iterator BBI = exitBlocks.begin(),
BBE = exitBlocks.end(); BBI != BBE; ++BBI) {
PHINode *phi = new PHINode(Instr->getType(), "lcssa", (*BBI)->begin());
workList.push_back(phi);
Phis[*BBI] = phi;
// Since LoopSimplify has been run, we know that all of these predecessors
// are in the loop, so just hook them up in the obvious manner.
//for (pred_iterator PI = pred_begin(*BBI), PE = pred_end(*BBI); PI != PE;
// ++PI)
// phi->addIncoming(Instr, *PI);
}
BBE = exitBlocks.end(); BBI != BBE; ++BBI)
if (DT->getNode(Instr->getParent())->dominates(DT->getNode(*BBI))) {
PHINode *phi = new PHINode(Instr->getType(), "lcssa", (*BBI)->begin());
workList.push_back(phi);
Phis[*BBI] = phi;
}
// Calculate the IDF of these LCSSA Phi nodes, inserting new Phi's where
// necessary. Keep track of these new Phi's in Phis.
@ -170,8 +165,7 @@ void LCSSA::processInstruction(Instruction* Instr,
PE = S.end(); P != PE; ++P) {
if (Phis[*P] == 0) {
// Still doesn't have operands...
PHINode *phi = new PHINode(Instr->getType(), "lcssa");
(*P)->getInstList().insert((*P)->front(), phi);
PHINode *phi = new PHINode(Instr->getType(), "lcssa", (*P)->begin());
Phis[*P] = phi;
workList.push_back(phi);
@ -208,8 +202,21 @@ void LCSSA::processInstruction(Instruction* Instr,
for (std::vector<Instruction*>::iterator II = Uses.begin(), IE = Uses.end();
II != IE; ++II) {
(*II)->replaceUsesOfWith(Instr, getValueDominatingBlock((*II)->getParent(),
Phis));
if (PHINode* phi = dyn_cast<PHINode>(*II)) {
for (unsigned int i = 0; i < phi->getNumIncomingValues(); ++i) {
// FIXME: Replace a Phi entry if and only if the corresponding
// predecessor is dominated.
Instruction* dominator =
getValueDominatingBlock(phi->getIncomingBlock(i), Phis);
if (phi->getIncomingValue(i) == Instr)
phi->setIncomingValue(i, dominator);
}
} else {
(*II)->replaceUsesOfWith(Instr,
getValueDominatingBlock((*II)->getParent(),
Phis));
}
}
}
@ -241,12 +248,17 @@ std::set<Instruction*> LCSSA::getLoopValuesUsedOutsideLoop(Loop *L,
Instruction *LCSSA::getValueDominatingBlock(BasicBlock *BB,
std::map<BasicBlock*, Instruction*> PotDoms) {
for (std::map<BasicBlock*, Instruction*>::iterator MI = PotDoms.begin(),
ME = PotDoms.end(); MI != ME; ++MI)
if (DT->getNode((*MI).first)->dominates(DT->getNode(BB)))
return (*MI).second;
DominatorTree::Node* bbNode = DT->getNode(BB);
while (bbNode != 0) {
std::map<BasicBlock*, Instruction*>::iterator I =
PotDoms.find(bbNode->getBlock());
if (I != PotDoms.end()) {
return (*I).second;
}
bbNode = bbNode->getIDom();
}
// FIXME: Should assert false
assert(0 && "No dominating value found.");
return 0;
}