[SCEV] Improve handling of pointer compares involving subtractions.perf/tmp

This patch improves handling of pointer comparisons involving
subtractions, if an offset is known to be positive.

Proof for isKnownPredicateSubIdiom: https://alive2.llvm.org/ce/z/Gfe8mS

Proof for getUDivExpr extension:a https://alive2.llvm.org/ce/z/H_G2Q0

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index ae1fff0fa844..643605ff352c 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1521,8 +1521,8 @@ bool IndVarSimplify::optimizeLoopExits(Loop *L, SCEVExpander &Rewriter) {
 
     // Can we prove that some other exit must be taken strictly before this
     // one?
-    if (SE->isLoopEntryGuardedByCond(L, CmpInst::ICMP_ULT,
-                                     MaxExitCount, ExitCount)) {
+    if (SE->isLoopEntryGuardedByCond(L, CmpInst::ICMP_ULT, MaxExitCount,
+                                     ExitCount)) {
       foldExit(L, ExitingBB, false, DeadInsts);
       Changed = true;
       continue;