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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101032 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2010-04-12 07:56:56 +00:00
parent 27dead44e0
commit d890f29ca6

View File

@ -406,6 +406,9 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
if (!isa<SCEVCouldNotCompute>(BackedgeTakenCount))
RewriteLoopExitValues(L, Rewriter);
// Simplify ICmp IV users.
EliminateIVComparisons();
// Compute the type of the largest recurrence expression, and decide whether
// a canonical induction variable should be inserted.
const Type *LargestType = 0;
@ -471,19 +474,10 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
ExitingBlock) {
assert(NeedCannIV &&
"LinearFunctionTestReplace requires a canonical induction variable");
// Can't rewrite non-branch yet.
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.
if (BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator()))
NewICmp = LinearFunctionTestReplace(L, BackedgeTakenCount, IndVar,
ExitingBlock, BI, Rewriter);
}
}
// Rewrite IV-derived expressions. Clears the rewriter cache.