[PATCH] D149419: [ValueTracking] Slight refactor to avoid unnecessary work; NFC

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n created this revision.
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Two changes:

1. Make some cases that conditionally returned unconditional.
2. In cases of `Op0 != 0 || Op1 != 0` its better check `Op1` first as its more likely to be a constant due to canonicalization (so faster to get knownbits of).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D149419

Files:
  llvm/lib/Analysis/ValueTracking.cpp


Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -2767,8 +2767,8 @@
                         I->getOperand(1));
   case Instruction::Or:
     // X | Y != 0 if X != 0 or Y != 0.
-    return isKnownNonZero(I->getOperand(0), DemandedElts, Depth, Q) ||
-           isKnownNonZero(I->getOperand(1), DemandedElts, Depth, Q);
+    return isKnownNonZero(I->getOperand(1), DemandedElts, Depth, Q) ||
+           isKnownNonZero(I->getOperand(0), DemandedElts, Depth, Q);
   case Instruction::SExt:
   case Instruction::ZExt:
     // ext X != 0 if X != 0.
@@ -2833,8 +2833,8 @@
     // non-zero.
     auto *BO = cast<OverflowingBinaryOperator>(V);
     if (Q.IIQ.hasNoUnsignedWrap(BO))
-      return isKnownNonZero(I->getOperand(0), DemandedElts, Depth, Q) ||
-             isKnownNonZero(I->getOperand(1), DemandedElts, Depth, Q);
+      return isKnownNonZero(I->getOperand(1), DemandedElts, Depth, Q) ||
+             isKnownNonZero(I->getOperand(0), DemandedElts, Depth, Q);
 
     if (isNonZeroAdd(DemandedElts, Depth, Q, BitWidth, I->getOperand(0),
                      I->getOperand(1)))
@@ -2935,10 +2935,8 @@
         break;
       case Intrinsic::umax:
       case Intrinsic::uadd_sat:
-        if (isKnownNonZero(II->getArgOperand(0), DemandedElts, Depth, Q) ||
-            isKnownNonZero(II->getArgOperand(1), DemandedElts, Depth, Q))
-          return true;
-        break;
+        return isKnownNonZero(II->getArgOperand(1), DemandedElts, Depth, Q) ||
+               isKnownNonZero(II->getArgOperand(0), DemandedElts, Depth, Q);
       case Intrinsic::smin:
       case Intrinsic::smax: {
         auto KnownOpImpliesNonZero = [&](const KnownBits &K) {


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