[llvm] r306503 - [IRCE][NFC] Better get SCEV for 1 in calculateSubRanges

[Max Kazantsev via llvm-commits]

Author: mkazantsev
Date: Tue Jun 27 21:57:45 2017
New Revision: 306503

URL: http://llvm.org/viewvc/llvm-project?rev=306503&view=rev
Log:
[IRCE][NFC] Better get SCEV for 1 in calculateSubRanges

A slightly more efficient way to get constant, we avoid resolving in getSCEV and excessive
invocations, and we don't create a ConstantInt if 'true' branch is taken.

Differential Revision: https://reviews.llvm.org/D34672

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

Modified: llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp?rev=306503&r1=306502&r2=306503&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp Tue Jun 27 21:57:45 2017
@@ -917,7 +917,6 @@ LoopConstrainer::calculateSubRanges() co
   // I think we can be more aggressive here and make this nuw / nsw if the
   // addition that feeds into the icmp for the latch's terminating branch is nuw
   // / nsw.  In any case, a wrapping 2's complement addition is safe.
-  ConstantInt *One = ConstantInt::get(Ty, 1);
   const SCEV *Start = SE.getSCEV(MainLoopStructure.IndVarStart);
   const SCEV *End = SE.getSCEV(MainLoopStructure.LoopExitAt);
 
@@ -948,8 +947,9 @@ LoopConstrainer::calculateSubRanges() co
     //    will be an empty range.  Returning an empty range is always safe.
     //
 
-    Smallest = SE.getAddExpr(End, SE.getSCEV(One));
-    Greatest = SE.getAddExpr(Start, SE.getSCEV(One));
+    const SCEV *One = SE.getOne(Ty);
+    Smallest = SE.getAddExpr(End, One);
+    Greatest = SE.getAddExpr(Start, One);
   }
 
   auto Clamp = [this, Smallest, Greatest](const SCEV *S) {