mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-15 20:29:48 +00:00
refactor some code to shrink PromoteMem2Reg::run a bit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40805 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
483ce14bf4
commit
bbe104002f
@ -16,6 +16,7 @@
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#define DEBUG_TYPE "mem2reg"
|
||||
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
|
||||
#include "llvm/Constants.h"
|
||||
#include "llvm/DerivedTypes.h"
|
||||
@ -26,12 +27,17 @@
|
||||
#include "llvm/ADT/DenseMap.h"
|
||||
#include "llvm/ADT/SmallPtrSet.h"
|
||||
#include "llvm/ADT/SmallVector.h"
|
||||
#include "llvm/ADT/Statistic.h"
|
||||
#include "llvm/ADT/StringExtras.h"
|
||||
#include "llvm/Support/CFG.h"
|
||||
#include "llvm/Support/Compiler.h"
|
||||
#include <algorithm>
|
||||
using namespace llvm;
|
||||
|
||||
STATISTIC(NumLocalPromoted, "Number of alloca's promoted within one block");
|
||||
STATISTIC(NumSingleStore, "Number of alloca's promoted with a single store");
|
||||
STATISTIC(NumDeadAlloca, "Number of dead alloca's removed");
|
||||
|
||||
// Provide DenseMapKeyInfo for all pointers.
|
||||
namespace llvm {
|
||||
template<>
|
||||
@ -153,6 +159,12 @@ namespace {
|
||||
}
|
||||
|
||||
private:
|
||||
void RemoveFromAllocasList(unsigned &AllocaIdx) {
|
||||
Allocas[AllocaIdx] = Allocas.back();
|
||||
Allocas.pop_back();
|
||||
--AllocaIdx;
|
||||
}
|
||||
|
||||
void MarkDominatingPHILive(BasicBlock *BB, unsigned AllocaNum,
|
||||
SmallPtrSet<PHINode*, 16> &DeadPHINodes);
|
||||
bool PromoteLocallyUsedAlloca(BasicBlock *BB, AllocaInst *AI);
|
||||
@ -165,6 +177,58 @@ namespace {
|
||||
bool QueuePhiNode(BasicBlock *BB, unsigned AllocaIdx, unsigned &Version,
|
||||
SmallPtrSet<PHINode*, 16> &InsertedPHINodes);
|
||||
};
|
||||
|
||||
struct AllocaInfo {
|
||||
std::vector<BasicBlock*> DefiningBlocks;
|
||||
std::vector<BasicBlock*> UsingBlocks;
|
||||
|
||||
StoreInst *OnlyStore;
|
||||
BasicBlock *OnlyBlock;
|
||||
bool OnlyUsedInOneBlock;
|
||||
|
||||
Value *AllocaPointerVal;
|
||||
|
||||
void clear() {
|
||||
DefiningBlocks.clear();
|
||||
UsingBlocks.clear();
|
||||
OnlyStore = 0;
|
||||
OnlyBlock = 0;
|
||||
OnlyUsedInOneBlock = true;
|
||||
AllocaPointerVal = 0;
|
||||
}
|
||||
|
||||
/// AnalyzeAlloca - Scan the uses of the specified alloca, filling in our
|
||||
/// ivars.
|
||||
void AnalyzeAlloca(AllocaInst *AI) {
|
||||
clear();
|
||||
|
||||
// As we scan the uses of the alloca instruction, keep track of stores,
|
||||
// and decide whether all of the loads and stores to the alloca are within
|
||||
// the same basic block.
|
||||
for (Value::use_iterator U = AI->use_begin(), E = AI->use_end();
|
||||
U != E; ++U){
|
||||
Instruction *User = cast<Instruction>(*U);
|
||||
if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
|
||||
// Remember the basic blocks which define new values for the alloca
|
||||
DefiningBlocks.push_back(SI->getParent());
|
||||
AllocaPointerVal = SI->getOperand(0);
|
||||
OnlyStore = SI;
|
||||
} else {
|
||||
LoadInst *LI = cast<LoadInst>(User);
|
||||
// Otherwise it must be a load instruction, keep track of variable reads
|
||||
UsingBlocks.push_back(LI->getParent());
|
||||
AllocaPointerVal = LI;
|
||||
}
|
||||
|
||||
if (OnlyUsedInOneBlock) {
|
||||
if (OnlyBlock == 0)
|
||||
OnlyBlock = User->getParent();
|
||||
else if (OnlyBlock != User->getParent())
|
||||
OnlyUsedInOneBlock = false;
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
} // end of anonymous namespace
|
||||
|
||||
@ -180,6 +244,8 @@ void PromoteMem2Reg::run() {
|
||||
|
||||
if (AST) PointerAllocaValues.resize(Allocas.size());
|
||||
|
||||
AllocaInfo Info;
|
||||
|
||||
for (unsigned AllocaNum = 0; AllocaNum != Allocas.size(); ++AllocaNum) {
|
||||
AllocaInst *AI = Allocas[AllocaNum];
|
||||
|
||||
@ -194,80 +260,46 @@ void PromoteMem2Reg::run() {
|
||||
AI->eraseFromParent();
|
||||
|
||||
// Remove the alloca from the Allocas list, since it has been processed
|
||||
Allocas[AllocaNum] = Allocas.back();
|
||||
Allocas.pop_back();
|
||||
--AllocaNum;
|
||||
RemoveFromAllocasList(AllocaNum);
|
||||
++NumDeadAlloca;
|
||||
continue;
|
||||
}
|
||||
|
||||
|
||||
// Calculate the set of read and write-locations for each alloca. This is
|
||||
// analogous to finding the 'uses' and 'definitions' of each variable.
|
||||
std::vector<BasicBlock*> DefiningBlocks;
|
||||
std::vector<BasicBlock*> UsingBlocks;
|
||||
|
||||
StoreInst *OnlyStore = 0;
|
||||
BasicBlock *OnlyBlock = 0;
|
||||
bool OnlyUsedInOneBlock = true;
|
||||
|
||||
// As we scan the uses of the alloca instruction, keep track of stores, and
|
||||
// decide whether all of the loads and stores to the alloca are within the
|
||||
// same basic block.
|
||||
Value *AllocaPointerVal = 0;
|
||||
for (Value::use_iterator U =AI->use_begin(), E = AI->use_end(); U != E;++U){
|
||||
Instruction *User = cast<Instruction>(*U);
|
||||
if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
|
||||
// Remember the basic blocks which define new values for the alloca
|
||||
DefiningBlocks.push_back(SI->getParent());
|
||||
AllocaPointerVal = SI->getOperand(0);
|
||||
OnlyStore = SI;
|
||||
} else {
|
||||
LoadInst *LI = cast<LoadInst>(User);
|
||||
// Otherwise it must be a load instruction, keep track of variable reads
|
||||
UsingBlocks.push_back(LI->getParent());
|
||||
AllocaPointerVal = LI;
|
||||
}
|
||||
|
||||
if (OnlyUsedInOneBlock) {
|
||||
if (OnlyBlock == 0)
|
||||
OnlyBlock = User->getParent();
|
||||
else if (OnlyBlock != User->getParent())
|
||||
OnlyUsedInOneBlock = false;
|
||||
}
|
||||
}
|
||||
Info.AnalyzeAlloca(AI);
|
||||
|
||||
// If the alloca is only read and written in one basic block, just perform a
|
||||
// linear sweep over the block to eliminate it.
|
||||
if (OnlyUsedInOneBlock) {
|
||||
LocallyUsedAllocas[OnlyBlock].push_back(AI);
|
||||
if (Info.OnlyUsedInOneBlock) {
|
||||
LocallyUsedAllocas[Info.OnlyBlock].push_back(AI);
|
||||
|
||||
// Remove the alloca from the Allocas list, since it will be processed.
|
||||
Allocas[AllocaNum] = Allocas.back();
|
||||
Allocas.pop_back();
|
||||
--AllocaNum;
|
||||
RemoveFromAllocasList(AllocaNum);
|
||||
continue;
|
||||
}
|
||||
|
||||
// If there is only a single store to this value, replace any loads of
|
||||
// it that are directly dominated by the definition with the value stored.
|
||||
if (DefiningBlocks.size() == 1) {
|
||||
if (Info.DefiningBlocks.size() == 1) {
|
||||
// Be aware of loads before the store.
|
||||
std::set<BasicBlock*> ProcessedBlocks;
|
||||
for (unsigned i = 0, e = UsingBlocks.size(); i != e; ++i)
|
||||
for (unsigned i = 0, e = Info.UsingBlocks.size(); i != e; ++i)
|
||||
// If the store dominates the block and if we haven't processed it yet,
|
||||
// do so now.
|
||||
if (dominates(OnlyStore->getParent(), UsingBlocks[i]))
|
||||
if (ProcessedBlocks.insert(UsingBlocks[i]).second) {
|
||||
BasicBlock *UseBlock = UsingBlocks[i];
|
||||
if (dominates(Info.OnlyStore->getParent(), Info.UsingBlocks[i]))
|
||||
if (ProcessedBlocks.insert(Info.UsingBlocks[i]).second) {
|
||||
BasicBlock *UseBlock = Info.UsingBlocks[i];
|
||||
|
||||
// If the use and store are in the same block, do a quick scan to
|
||||
// verify that there are no uses before the store.
|
||||
if (UseBlock == OnlyStore->getParent()) {
|
||||
if (UseBlock == Info.OnlyStore->getParent()) {
|
||||
BasicBlock::iterator I = UseBlock->begin();
|
||||
for (; &*I != OnlyStore; ++I) { // scan block for store.
|
||||
for (; &*I != Info.OnlyStore; ++I) { // scan block for store.
|
||||
if (isa<LoadInst>(I) && I->getOperand(0) == AI)
|
||||
break;
|
||||
}
|
||||
if (&*I != OnlyStore) break; // Do not handle this case.
|
||||
if (&*I != Info.OnlyStore) break; // Do not handle this case.
|
||||
}
|
||||
|
||||
// Otherwise, if this is a different block or if all uses happen
|
||||
@ -277,7 +309,7 @@ void PromoteMem2Reg::run() {
|
||||
I != E; ) {
|
||||
if (LoadInst *LI = dyn_cast<LoadInst>(I++)) {
|
||||
if (LI->getOperand(0) == AI) {
|
||||
LI->replaceAllUsesWith(OnlyStore->getOperand(0));
|
||||
LI->replaceAllUsesWith(Info.OnlyStore->getOperand(0));
|
||||
if (AST && isa<PointerType>(LI->getType()))
|
||||
AST->deleteValue(LI);
|
||||
LI->eraseFromParent();
|
||||
@ -286,23 +318,22 @@ void PromoteMem2Reg::run() {
|
||||
}
|
||||
|
||||
// Finally, remove this block from the UsingBlock set.
|
||||
UsingBlocks[i] = UsingBlocks.back();
|
||||
Info.UsingBlocks[i] = Info.UsingBlocks.back();
|
||||
--i; --e;
|
||||
}
|
||||
|
||||
// Finally, after the scan, check to see if the store is all that is left.
|
||||
if (UsingBlocks.empty()) {
|
||||
if (Info.UsingBlocks.empty()) {
|
||||
++NumSingleStore;
|
||||
// The alloca has been processed, move on.
|
||||
Allocas[AllocaNum] = Allocas.back();
|
||||
Allocas.pop_back();
|
||||
--AllocaNum;
|
||||
RemoveFromAllocasList(AllocaNum);
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
if (AST)
|
||||
PointerAllocaValues[AllocaNum] = AllocaPointerVal;
|
||||
PointerAllocaValues[AllocaNum] = Info.AllocaPointerVal;
|
||||
|
||||
// If we haven't computed a numbering for the BB's in the function, do so
|
||||
// now.
|
||||
@ -318,9 +349,9 @@ void PromoteMem2Reg::run() {
|
||||
unsigned CurrentVersion = 0;
|
||||
SmallPtrSet<PHINode*, 16> InsertedPHINodes;
|
||||
std::vector<std::pair<unsigned, BasicBlock*> > DFBlocks;
|
||||
while (!DefiningBlocks.empty()) {
|
||||
BasicBlock *BB = DefiningBlocks.back();
|
||||
DefiningBlocks.pop_back();
|
||||
while (!Info.DefiningBlocks.empty()) {
|
||||
BasicBlock *BB = Info.DefiningBlocks.back();
|
||||
Info.DefiningBlocks.pop_back();
|
||||
|
||||
// Look up the DF for this write, add it to PhiNodes
|
||||
DominanceFrontier::const_iterator it = DF.find(BB);
|
||||
@ -342,7 +373,7 @@ void PromoteMem2Reg::run() {
|
||||
for (unsigned i = 0, e = DFBlocks.size(); i != e; ++i) {
|
||||
BasicBlock *BB = DFBlocks[i].second;
|
||||
if (QueuePhiNode(BB, AllocaNum, CurrentVersion, InsertedPHINodes))
|
||||
DefiningBlocks.push_back(BB);
|
||||
Info.DefiningBlocks.push_back(BB);
|
||||
}
|
||||
DFBlocks.clear();
|
||||
}
|
||||
@ -355,9 +386,9 @@ void PromoteMem2Reg::run() {
|
||||
// marked alive because of loads which are dominated by stores, but there
|
||||
// will be no unmarked PHI nodes which are actually used.
|
||||
//
|
||||
for (unsigned i = 0, e = UsingBlocks.size(); i != e; ++i)
|
||||
MarkDominatingPHILive(UsingBlocks[i], AllocaNum, InsertedPHINodes);
|
||||
UsingBlocks.clear();
|
||||
for (unsigned i = 0, e = Info.UsingBlocks.size(); i != e; ++i)
|
||||
MarkDominatingPHILive(Info.UsingBlocks[i], AllocaNum, InsertedPHINodes);
|
||||
Info.UsingBlocks.clear();
|
||||
|
||||
// If there are any PHI nodes which are now known to be dead, remove them!
|
||||
for (SmallPtrSet<PHINode*, 16>::iterator I = InsertedPHINodes.begin(),
|
||||
@ -623,6 +654,8 @@ bool PromoteMem2Reg::PromoteLocallyUsedAlloca(BasicBlock *BB, AllocaInst *AI) {
|
||||
assert(AI->use_empty() && "Uses of alloca from more than one BB??");
|
||||
if (AST) AST->deleteValue(AI);
|
||||
AI->getParent()->getInstList().erase(AI);
|
||||
|
||||
++NumLocalPromoted;
|
||||
return false;
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user