[llvm] eddecd3 - [SCEV] Increase FoldID bits size cover common cases.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2023-02-24T09:41:53+01:00
New Revision: eddecd3ade5ce1b827dafb84e8137cc6f89576fb

URL: https://github.com/llvm/llvm-project/commit/eddecd3ade5ce1b827dafb84e8137cc6f89576fb
DIFF: https://github.com/llvm/llvm-project/commit/eddecd3ade5ce1b827dafb84e8137cc6f89576fb.diff

LOG: [SCEV] Increase FoldID bits size cover common cases.

This should fix the regressions introduced by a53d940cee6f by making
sure no dynamic allocations are needed in the common case, while
retaining support for arbitrary SCEV expressions.

Alternative to D144335.

Compile-time impact:
* NewPM-O3: -0.11%
* NewPM-ReleaseThinLTO: -0.10%
*NewPM-ReleaseLTO-g: -0.08%

https://llvm-compile-time-tracker.com/compare.php?from=df016a9525e5722dfd1e1e1632cec3ed7b33bc8a&to=c1c64de4a973bcecaddbc4038a539234eb39413b&stat=instructions:u

Reviewed By: vitalybuka, nikic

Differential Revision: https://reviews.llvm.org/D144382

Added: 
    

Modified: 
    llvm/include/llvm/Analysis/ScalarEvolution.h

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
index 57107cb8d367c..51b67d1756b9a 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolution.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -1297,7 +1297,7 @@ class ScalarEvolution {
   bool loopIsFiniteByAssumption(const Loop *L);
 
   class FoldID {
-    SmallVector<unsigned, 4> Bits;
+    SmallVector<unsigned, 5> Bits;
 
   public:
     void addInteger(unsigned long I) {