[PATCH] D48238: [SCEV] Simplify some flags expressions.

[Justin Lebar via Phabricator via llvm-commits]

jlebar created this revision.
jlebar added a reviewer: sanjoy.
Herald added a subscriber: hiraditya.

Sending for presubmit review out of an abundance of caution; it would be
bad to mess this up.


https://reviews.llvm.org/D48238

Files:
  llvm/lib/Analysis/ScalarEvolution.cpp


Index: llvm/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/lib/Analysis/ScalarEvolution.cpp
+++ llvm/lib/Analysis/ScalarEvolution.cpp
@@ -3897,7 +3897,7 @@
   auto AddFlags = SCEV::FlagAnyWrap;
   const bool RHSIsNotMinSigned =
       !getSignedRangeMin(RHS).isMinSignedValue();
-  if ((Flags & SCEV::FlagNSW) == SCEV::FlagNSW) {
+  if (Flags & SCEV::FlagNSW) {
     // Let M be the minimum representable signed value. Then (-1)*RHS
     // signed-wraps if and only if RHS is M. That can happen even for
     // a NSW subtraction because e.g. (-1)*M signed-wraps even though
@@ -11940,7 +11940,7 @@
   SCEV::NoWrapFlags ScevFlags = AR->getNoWrapFlags();
   IncrementWrapFlags IFlags = Flags;
 
-  if ((ScevFlags | SCEV::FlagNSW) == ScevFlags)
+  if (ScevFlags & SCEV::FlagNSW)
     IFlags &= ~IncrementNSSW;
 
   return IFlags == IncrementAnyWrap;
@@ -11962,10 +11962,10 @@
   SCEV::NoWrapFlags StaticFlags = AR->getNoWrapFlags();
 
   // We can safely transfer the NSW flag as NSSW.
-  if ((StaticFlags | SCEV::FlagNSW) == StaticFlags)
+  if (StaticFlags & SCEV::FlagNSW)
     ImpliedFlags = IncrementNSSW;
 
-  if ((StaticFlags | SCEV::FlagNUW) == StaticFlags) {
+  if (StaticFlags & SCEV::FlagNUW) {
     // If the increment is positive, the SCEV NUW flag will also imply the
     // WrapPredicate NUSW flag.
     if (const auto *Step = dyn_cast<SCEVConstant>(AR->getStepRecurrence(SE)))


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D48238.151555.patch
Type: text/x-patch
Size: 1454 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180615/f7ce9a13/attachment.bin>