[llvm-commits] [llvm] r146302 - /llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp

[Andrew Trick]

Author: atrick
Date: Fri Dec  9 18:25:00 2011
New Revision: 146302

URL: http://llvm.org/viewvc/llvm-project?rev=146302&view=rev
Log:
LSR: ignore strides in outer loops.

Since we're not rewriting IVs in other loops, there's not much reason
to consider their stride when generating formulae.
This should reduce the number of useless formulas considered by LSR.

Modified:
    llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=146302&r1=146301&r2=146302&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Fri Dec  9 18:25:00 2011
@@ -2061,7 +2061,8 @@
     do {
       const SCEV *S = Worklist.pop_back_val();
       if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
-        Strides.insert(AR->getStepRecurrence(SE));
+        if (EnableNested || AR->getLoop() == L)
+          Strides.insert(AR->getStepRecurrence(SE));
         Worklist.push_back(AR->getStart());
       } else if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
         Worklist.append(Add->op_begin(), Add->op_end());