6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-04 21:30:49 +00:00
Code Issues Projects Releases Wiki Activity

fix an issue duncan pointed out, which could cause loop rotate

Browse Source 
to violate LCSSA form


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123066 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-01-08 17:38:45 +00:00
parent b434acb7be
commit 012ca949af
1 changed files with 16 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
lib/Transforms/Scalar/LoopRotation.cpp
View File

@ -70,6 +70,7 @@ namespace {
void preserveCanonicalLoopForm(LPPassManager &LPM);
private:
LoopInfo *LI;
Loop *L;
BasicBlock *OrigHeader;
BasicBlock *OrigPreHeader;
@ -89,21 +90,31 @@ INITIALIZE_PASS_END(LoopRotate, "loop-rotate", "Rotate Loops", false, false)
Pass *llvm::createLoopRotatePass() { return new LoopRotate(); }
/// Initialize local data
void LoopRotate::initialize() {
L = NULL;
OrigHeader = NULL;
OrigPreHeader = NULL;
NewHeader = NULL;
Exit = NULL;
}
/// Rotate Loop L as many times as possible. Return true if
/// the loop is rotated at least once.
bool LoopRotate::runOnLoop(Loop *Lp, LPPassManager &LPM) {
LI = &getAnalysis<LoopInfo>();
bool RotatedOneLoop = false;
initialize();
LPM_Ptr = &LPM;
// One loop can be rotated multiple times.
bool MadeChange = false;
while (rotateLoop(Lp,LPM)) {
RotatedOneLoop = true;
MadeChange = true;
initialize();
}
return RotatedOneLoop;
return MadeChange;
}
/// Rotate loop LP. Return true if the loop is rotated.
@ -213,7 +224,8 @@ bool LoopRotate::rotateLoop(Loop *Lp, LPPassManager &LPM) {
// With the operands remapped, see if the instruction constant folds or is
// otherwise simplifyable. This commonly occurs because the entry from PHI
// nodes allows icmps and other instructions to fold.
if (Value *V = SimplifyInstruction(C)) {
Value *V = SimplifyInstruction(C);
if (V && LI->replacementPreservesLCSSAForm(C, V)) {
// If so, then delete the temporary instruction and stick the folded value
// in the map.
delete C;
@ -322,14 +334,6 @@ bool LoopRotate::rotateLoop(Loop *Lp, LPPassManager &LPM) {
return true;
}
/// Initialize local data
void LoopRotate::initialize() {
L = NULL;
OrigHeader = NULL;
OrigPreHeader = NULL;
NewHeader = NULL;
Exit = NULL;
}
/// After loop rotation, loop pre-header has multiple sucessors.
/// Insert one forwarding basic block to ensure that loop pre-header