diff options
Diffstat (limited to 'lib/Transforms/Scalar/IndVarSimplify.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/IndVarSimplify.cpp | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp index ce1307c..17f7d98 100644 --- a/lib/Transforms/Scalar/IndVarSimplify.cpp +++ b/lib/Transforms/Scalar/IndVarSimplify.cpp @@ -471,6 +471,13 @@ void IndVarSimplify::RewriteIVExpressions(Loop *L, const Type *LargestType, // Compute the final addrec to expand into code. const SCEV *AR = IU->getReplacementExpr(*UI); + // Evaluate the expression out of the loop, if possible. + if (!L->contains(UI->getUser())) { + const SCEV *ExitVal = SE->getSCEVAtScope(AR, L->getParentLoop()); + if (ExitVal->isLoopInvariant(L)) + AR = ExitVal; + } + // FIXME: It is an extremely bad idea to indvar substitute anything more // complex than affine induction variables. Doing so will put expensive // polynomial evaluations inside of the loop, and the str reduction pass @@ -522,11 +529,10 @@ void IndVarSimplify::RewriteIVExpressions(Loop *L, const Type *LargestType, Rewriter.clear(); // Now that we're done iterating through lists, clean up any instructions // which are now dead. - while (!DeadInsts.empty()) { - Instruction *Inst = dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val()); - if (Inst) + while (!DeadInsts.empty()) + if (Instruction *Inst = + dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val())) RecursivelyDeleteTriviallyDeadInstructions(Inst); - } } /// If there's a single exit block, sink any loop-invariant values that |
