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| author | Wojciech Matyjewicz <wmatyjewicz@fastmail.fm> | 2008-02-11 18:37:34 +0000 |
|---|---|---|
| committer | Wojciech Matyjewicz <wmatyjewicz@fastmail.fm> | 2008-02-11 18:37:34 +0000 |
| commit | ffba5f8dd3291be7a00d83c1006f511ae7e32a42 (patch) | |
| tree | 6a3e33c1f47c3727fe9ff796ae3a1e716f63b69c /lib/Analysis | |
| parent | dc71c8051d354cad8673e651209e431584310d5b (diff) | |
| download | external_llvm-ffba5f8dd3291be7a00d83c1006f511ae7e32a42.zip external_llvm-ffba5f8dd3291be7a00d83c1006f511ae7e32a42.tar.gz external_llvm-ffba5f8dd3291be7a00d83c1006f511ae7e32a42.tar.bz2 | |
If the LHS of the comparison is a loop-invariant we also want to move it
to the RHS. This simple change allows to compute loop iteration count
for loops with condition similar to the one in the testcase (which seems
to be quite common).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46959 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis')
| -rw-r--r-- | lib/Analysis/ScalarEvolution.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index cbfc563..122dba3 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -1819,8 +1819,8 @@ SCEVHandle ScalarEvolutionsImpl::ComputeIterationCount(const Loop *L) { // At this point, we would like to compute how many iterations of the // loop the predicate will return true for these inputs. - if (isa<SCEVConstant>(LHS) && !isa<SCEVConstant>(RHS)) { - // If there is a constant, force it into the RHS. + if (LHS->isLoopInvariant(L) && !RHS->isLoopInvariant(L)) { + // If there is a loop-invariant, force it into the RHS. std::swap(LHS, RHS); Cond = ICmpInst::getSwappedPredicate(Cond); } |