6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-13 22:24:07 +00:00
Code Issues Projects Releases Wiki Activity

Do not ignore iv uses outside the loop.

Browse Source 
This one slipped through cracks very well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56284 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Devang Patel
2008-09-17 17:53:47 +00:00
parent 442b1aa94b
commit 00622952ce
4 changed files with 101 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
lib/Transforms/Scalar/LoopIndexSplit.cpp
View File

@ -111,6 +111,10 @@ namespace {
/// instruction then loop body is executed only for one iteration. In
/// such case eliminate loop structure surrounding this loop body. For
bool processOneIterationLoop(SplitInfo &SD);
/// isOneIterationLoop - Return true if split condition is EQ and
/// the IV is not used outside the loop.
bool isOneIterationLoop(ICmpInst *CI);
void updateLoopBounds(ICmpInst *CI);
/// updateLoopIterationSpace - Current loop body is covered by an AND
@ -248,7 +252,7 @@ bool LoopIndexSplit::runOnLoop(Loop *IncomingLoop, LPPassManager &LPM_Ref) {
SI = SplitData.erase(Delete_SI);
}
}
else if (CI && CI->getPredicate() == ICmpInst::ICMP_EQ) {
else if (isOneIterationLoop(CI)) {
Changed = processOneIterationLoop(SD);
if (Changed) {
++NumIndexSplit;
@ -276,6 +280,22 @@ bool LoopIndexSplit::runOnLoop(Loop *IncomingLoop, LPPassManager &LPM_Ref) {
return Changed;
}
/// isOneIterationLoop - Return true if split condition is EQ and
/// the IV is not used outside the loop.
bool LoopIndexSplit::isOneIterationLoop(ICmpInst *CI) {
if (!CI)
return false;
if (CI->getPredicate() != ICmpInst::ICMP_EQ)
return false;
Value *Incr = IndVar->getIncomingValueForBlock(L->getLoopLatch());
for (Value::use_iterator UI = Incr->use_begin(), E = Incr->use_end();
UI != E; ++UI)
if (!L->contains(cast<Instruction>(*UI)->getParent()))
return false;
return true;
}
/// Return true if V is a induction variable or induction variable's
/// increment for loop L.
void LoopIndexSplit::findIndVar(Value *V, Loop *L) {