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Move the EliminateIVUsers call back out to its original location. Now that 

a ScalarEvolution bug with overflow handling is fixed, the normal analysis
code will automatically decline to operate on the icmp instructions which
are responsible for the loop exit.

llvm-svn: 101032
This commit is contained in:
Dan Gohman 2010-04-12 07:56:56 +00:00
parent 7531ca96f7
commit 07f6563e81
1 changed files with 4 additions and 10 deletions
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14
llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
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@ -406,6 +406,9 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount)) if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount))
RewriteLoopExitValues(L, Rewriter); RewriteLoopExitValues(L, Rewriter);
// Simplify ICmp IV users.
EliminateIVComparisons();
// Compute the type of the largest recurrence expression, and decide whether // Compute the type of the largest recurrence expression, and decide whether
// a canonical induction variable should be inserted. // a canonical induction variable should be inserted.
const Type *LargestType = 0; const Type *LargestType = 0;
@ -471,20 +474,11 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
ExitingBlock) { ExitingBlock) {
assert(NeedCannIV && assert(NeedCannIV &&
"LinearFunctionTestReplace requires a canonical induction variable"); "LinearFunctionTestReplace requires a canonical induction variable");
// Can't rewrite non-branch yet. // Can't rewrite non-branch yet.
if (BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator())) { if (BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator()))
// Eliminate comparisons which are always true or always false, due to
// the known backedge-taken count. This may include comparisons which
// are currently controlling (part of) the loop exit, so we can only do
// it when we know we're going to insert our own loop exit code.
EliminateIVComparisons();
// Insert new loop exit code.
NewICmp = LinearFunctionTestReplace(L, BackedgeTakenCount, IndVar, NewICmp = LinearFunctionTestReplace(L, BackedgeTakenCount, IndVar,
ExitingBlock, BI, Rewriter); ExitingBlock, BI, Rewriter);
} }
}
// Rewrite IV-derived expressions. Clears the rewriter cache. // Rewrite IV-derived expressions. Clears the rewriter cache.
RewriteIVExpressions(L, Rewriter); RewriteIVExpressions(L, Rewriter);