[llvm-commits] [llvm] r52275 - /llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
Wojciech Matyjewicz
wmatyjewicz at fastmail.fm
Sat Jun 14 09:48:23 PDT 2008
Author: wmat
Date: Sat Jun 14 11:48:22 2008
New Revision: 52275
URL: http://llvm.org/viewvc/llvm-project?rev=52275&view=rev
Log:
Change 'while' loop to 'do' loop.
Add a safety measure. It isn't safe to assume in ScalarEvolutionExpander that
all loops are in canonical form (but it should be safe for loops that have
AddRecs).
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Modified:
llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=52275&r1=52274&r2=52275&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Sat Jun 14 11:48:22 2008
@@ -185,14 +185,21 @@
Loop *InsertPtLoop = LI.getLoopFor(MulInsertPt->getParent());
if (InsertPtLoop != L && InsertPtLoop &&
L->contains(InsertPtLoop->getHeader())) {
- while (InsertPtLoop != L) {
+ do {
// If we cannot hoist the multiply out of this loop, don't.
if (!InsertPtLoop->isLoopInvariant(F)) break;
- // Otherwise, move the insert point to the preheader of the loop.
- MulInsertPt = InsertPtLoop->getLoopPreheader()->getTerminator();
+ BasicBlock *InsertPtLoopPH = InsertPtLoop->getLoopPreheader();
+
+ // If this loop hasn't got a preheader, we aren't able to hoist the
+ // multiply.
+ if (!InsertPtLoopPH)
+ break;
+
+ // Otherwise, move the insert point to the preheader.
+ MulInsertPt = InsertPtLoopPH->getTerminator();
InsertPtLoop = InsertPtLoop->getParentLoop();
- }
+ } while (InsertPtLoop != L);
}
return InsertBinop(Instruction::Mul, I, F, MulInsertPt);
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