6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-08 03:30:22 +00:00
Code Issues Projects Releases Wiki Activity

Major think-o. Iterate over all live out-of-loop values, and perform the

Browse Source 
other calculations on each individually, rather than trying to delay it and do
them all at the end.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28527 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2006-05-28 19:33:28 +00:00
parent 492196c89f
commit bd82277cbb
1 changed files with 36 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
lib/Transforms/Utils/LCSSA.cpp
View File

@ -42,7 +42,8 @@
using namespace llvm; using namespace llvm;
namespace { namespace {
static Statistic<> NumLCSSA("lcssa", "Number of live out of a loop"); static Statistic<> NumLCSSA("lcssa",
"Number of live out of a loop variables");
class LCSSA : public FunctionPass { class LCSSA : public FunctionPass {
public: public:
@ -125,50 +126,49 @@ bool LCSSA::visitSubloop(Loop* L) {
++PI) ++PI)
phi->addIncoming(*I, *PI); phi->addIncoming(*I, *PI);
} }
}
// Calculate the IDF of these LCSSA Phi nodes, inserting new Phi's where // Calculate the IDF of these LCSSA Phi nodes, inserting new Phi's where
// necessary. Keep track of these new Phi's in DFPhis. // necessary. Keep track of these new Phi's in DFPhis.
std::map<BasicBlock*, PHINode*> DFPhis; std::map<BasicBlock*, PHINode*> DFPhis;
for (std::vector<PHINode*>::iterator I = workList.begin(), for (std::vector<PHINode*>::iterator DFI = workList.begin(),
E = workList.end(); I != E; ++I) { E = workList.end(); DFI != E; ++DFI) {
// Get the current Phi's DF, and insert Phi nodes. Add these new // Get the current Phi's DF, and insert Phi nodes. Add these new
// nodes to our worklist. // nodes to our worklist.
DominanceFrontier::const_iterator it = DF->find((*I)->getParent()); DominanceFrontier::const_iterator it = DF->find((*DFI)->getParent());
if (it != DF->end()) { if (it != DF->end()) {
const DominanceFrontier::DomSetType &S = it->second; const DominanceFrontier::DomSetType &S = it->second;
for (DominanceFrontier::DomSetType::const_iterator P = S.begin(), for (DominanceFrontier::DomSetType::const_iterator P = S.begin(),
PE = S.end(); P != PE; ++P) { PE = S.end(); P != PE; ++P) {
if (DFPhis[*P] == 0) { if (DFPhis[*P] == 0) {
// Still doesn't have operands... // Still doesn't have operands...
PHINode *phi = new PHINode((*I)->getType(), "lcssa"); PHINode *phi = new PHINode((*DFI)->getType(), "lcssa");
(*P)->getInstList().insert((*P)->front(), phi); (*P)->getInstList().insert((*P)->front(), phi);
DFPhis[*P] = phi; DFPhis[*P] = phi;
workList.push_back(phi); workList.push_back(phi);
}
} }
} }
}
// Get the predecessor blocks of the current Phi, and use them to hook up // Get the predecessor blocks of the current Phi, and use them to hook up
// the operands of the current Phi to any members of DFPhis that dominate // the operands of the current Phi to any members of DFPhis that dominate
// it. This is a nop for the Phis inserted directly in the exit blocks, // it. This is a nop for the Phis inserted directly in the exit blocks,
// since they are not dominated by any members of DFPhis. // since they are not dominated by any members of DFPhis.
for (pred_iterator PI = pred_begin((*I)->getParent()), for (pred_iterator PI = pred_begin((*DFI)->getParent()),
E = pred_end((*I)->getParent()); PI != E; ++PI) E = pred_end((*DFI)->getParent()); PI != E; ++PI)
for (std::map<BasicBlock*, PHINode*>::iterator MI = DFPhis.begin(), for (std::map<BasicBlock*, PHINode*>::iterator MI = DFPhis.begin(),
ME = DFPhis.end(); MI != ME; ++MI) ME = DFPhis.end(); MI != ME; ++MI)
if (DT->getNode((*MI).first)->dominates(DT->getNode(*PI))) { if (DT->getNode((*MI).first)->dominates(DT->getNode(*PI))) {
(*I)->addIncoming((*MI).second, *PI); (*DFI)->addIncoming((*MI).second, *PI);
// Since dominate() is not cheap, don't do it more than we have to. // Since dominate() is not cheap, don't do it more than we have to.
break; break;
} }
}
// FIXME: Should update all uses.
} }
// FIXME: Should update all uses.
return true; // FIXME: Should be more intelligent in our return value. return true; // FIXME: Should be more intelligent in our return value.
} }