diff options
| -rw-r--r-- | lib/Analysis/ScalarEvolution.cpp | 4 | ||||
| -rw-r--r-- | test/Analysis/ScalarEvolution/2008-02-11-ReversedCondition.ll | 15 |
2 files changed, 17 insertions, 2 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index cbfc56373a..122dba3e6a 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); } diff --git a/test/Analysis/ScalarEvolution/2008-02-11-ReversedCondition.ll b/test/Analysis/ScalarEvolution/2008-02-11-ReversedCondition.ll new file mode 100644 index 0000000000..3cdb1e3c76 --- /dev/null +++ b/test/Analysis/ScalarEvolution/2008-02-11-ReversedCondition.ll @@ -0,0 +1,15 @@ +; RUN: llvm-as < %s | opt -scalar-evolution -analyze | not grep Unpredictable + +define void @foo(i32 %n) { +entry: + br label %header +header: + %i = phi i32 [ 0, %entry ], [ %i.inc, %next ] + %cond = icmp sgt i32 %n, %i + br i1 %cond, label %next, label %return +next: + %i.inc = add i32 %i, 1 + br label %header +return: + ret void +} |