[llvm] ab7ef35 - Revert "[SCEV] Handle non-positive case in isImpliedViaOperations"

[Max Kazantsev via llvm-commits]

Author: Max Kazantsev
Date: 2020-11-05T11:27:55+07:00
New Revision: ab7ef35d3460762165be8b22eb2a07a808f8f828

URL: https://github.com/llvm/llvm-project/commit/ab7ef35d3460762165be8b22eb2a07a808f8f828
DIFF: https://github.com/llvm/llvm-project/commit/ab7ef35d3460762165be8b22eb2a07a808f8f828.diff

LOG: Revert "[SCEV] Handle non-positive case in isImpliedViaOperations"

This reverts commit 8dc98897c4af20aeb52f1f19f538c08e55793283.

Commited by mistake.

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolution.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index a385cd4e8dc2..77fc2d47785d 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -10653,32 +10653,21 @@ bool ScalarEvolution::isImpliedViaOperations(ICmpInst::Predicate Pred,
   }
 
   // For unsigned, try to reduce it to corresponding signed comparison.
-  if (Pred == ICmpInst::ICMP_UGT) {
+  if (Pred == ICmpInst::ICMP_UGT)
     // We can replace unsigned predicate with its signed counterpart if all
-    // involved values are non-negative or non-positive.
+    // involved values are non-negative.
     // TODO: We could have better support for unsigned.
-    auto IsNonNegativeOrNonPositive = [this](const SCEV *S) {
-      return isKnownNonNegative(S) || isKnownNonPositive(S);
-    };
-    if (IsNonNegativeOrNonPositive(FoundLHS) &&
-        IsNonNegativeOrNonPositive(FoundRHS)) {
-      // Knowing that both FoundLHS and FoundRHS are non-negative/non-
-      // positive, and knowing FoundLHS >u FoundRHS, we also know that
-      // FoundLHS >s FoundRHS. Let us use this fact to prove that LHS and RHS
-      // are non-negative or non-positive.
-      const SCEV *One = getMinusOne(LHS->getType());
+    if (isKnownNonNegative(FoundLHS) && isKnownNonNegative(FoundRHS)) {
+      // Knowing that both FoundLHS and FoundRHS are non-negative, and knowing
+      // FoundLHS >u FoundRHS, we also know that FoundLHS >s FoundRHS. Let us
+      // use this fact to prove that LHS and RHS are non-negative.
       const SCEV *MinusOne = getMinusOne(LHS->getType());
-      auto IsImpliedNonNegativeOrNonPositive = [&](const SCEV *S) {
-        return isImpliedCondOperands(ICmpInst::ICMP_SGT, S, MinusOne, FoundLHS,
-                                     FoundRHS) ||
-               isImpliedCondOperands(ICmpInst::ICMP_SGT, One, S, FoundLHS,
-                                     FoundRHS);
-      };
-      if (IsImpliedNonNegativeOrNonPositive(LHS) &&
-          IsImpliedNonNegativeOrNonPositive(RHS))
+      if (isImpliedCondOperands(ICmpInst::ICMP_SGT, LHS, MinusOne, FoundLHS,
+                                FoundRHS) &&
+          isImpliedCondOperands(ICmpInst::ICMP_SGT, RHS, MinusOne, FoundLHS,
+                                FoundRHS))
         Pred = ICmpInst::ICMP_SGT;
     }
-  }
 
   if (Pred != ICmpInst::ICMP_SGT)
     return false;