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authorDan Gohman <gohman@apple.com>2010-01-21 02:09:26 +0000
committerDan Gohman <gohman@apple.com>2010-01-21 02:09:26 +0000
commita10756ee657a4d43a48cca5c166919093930ed6b (patch)
tree52a9cf0b867521026963ca127f6a46d19f0f8f78 /lib/Analysis/IVUsers.cpp
parentac8b4bf66b7263018fe6c133604a30780c24982e (diff)
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Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in cases where it reduces register pressure, and also more aggressive about rewriting induction variables to count down (or up) to zero when doing so reduces register pressure. It currently uses fairly simplistic algorithms for finding reuse opportunities, but it introduces a new framework allows it to combine multiple strategies at once to form hybrid solutions, instead of doing all full-reduction or all base+index. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94061 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/IVUsers.cpp')
-rw-r--r--lib/Analysis/IVUsers.cpp6
1 files changed, 0 insertions, 6 deletions
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index 92f00273a2..38611ccb62 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -324,12 +324,6 @@ const SCEV *IVUsers::getReplacementExpr(const IVStrideUse &U) const {
// the actual replacement value.
if (U.isUseOfPostIncrementedValue())
RetVal = SE->getAddExpr(RetVal, U.getParent()->Stride);
- // Evaluate the expression out of the loop, if possible.
- if (!L->contains(U.getUser())) {
- const SCEV *ExitVal = SE->getSCEVAtScope(RetVal, L->getParentLoop());
- if (ExitVal->isLoopInvariant(L))
- RetVal = ExitVal;
- }
return RetVal;
}