[PATCH] D156141: [NFC][ValueTracking]: Move some code from isKnownNonZero to isKnownNonZeroFromOperator

[Dhruv Chawla via Phabricator via llvm-commits]

0xdc03 created this revision.
0xdc03 added a reviewer: nikic.
Herald added subscribers: StephenFan, hiraditya.
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There is some pointer simplification code originally from isKnownNonNull
that is now better suited to be in isKnownNonZeroFromOperator.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D156141

Files:
  llvm/lib/Analysis/ValueTracking.cpp


Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -2454,6 +2454,12 @@
                                        unsigned Depth, const SimplifyQuery &Q) {
   unsigned BitWidth = getBitWidth(I->getType()->getScalarType(), Q.DL);
   switch (I->getOpcode()) {
+  case Instruction::Alloca:
+    // Alloca never returns null, malloc might.
+    if (PointerType *PtrTy = dyn_cast<PointerType>(I->getType());
+        PtrTy && PtrTy->getAddressSpace() == 0)
+      return true;
+    break;
   case Instruction::GetElementPtr:
     if (I->getType()->isPointerTy())
       return isGEPKnownNonNull(cast<GEPOperator>(I), Depth, Q);
@@ -2688,6 +2694,13 @@
     // handled in isKnownNonZero.
     return false;
   case Instruction::Call:
+    if (const auto *Call = dyn_cast<CallBase>(I)) {
+      if (Call->isReturnNonNull())
+        return true;
+      if (const auto *RP = getArgumentAliasingToReturnedPointer(Call, true))
+        return isKnownNonZero(RP, Depth, Q);
+    }
+
     if (auto *II = dyn_cast<IntrinsicInst>(I)) {
       switch (II->getIntrinsicID()) {
       case Intrinsic::sshl_sat:
@@ -2838,10 +2851,6 @@
   // Check for pointer simplifications.
 
   if (PointerType *PtrTy = dyn_cast<PointerType>(V->getType())) {
-    // Alloca never returns null, malloc might.
-    if (isa<AllocaInst>(V) && PtrTy->getAddressSpace() == 0)
-      return true;
-
     // A byval, inalloca may not be null in a non-default addres space. A
     // nonnull argument is assumed never 0.
     if (const Argument *A = dyn_cast<Argument>(V)) {
@@ -2850,13 +2859,6 @@
            A->hasNonNullAttr()))
         return true;
     }
-
-    if (const auto *Call = dyn_cast<CallBase>(V)) {
-      if (Call->isReturnNonNull())
-        return true;
-      if (const auto *RP = getArgumentAliasingToReturnedPointer(Call, true))
-        return isKnownNonZero(RP, Depth, Q);
-    }
   }
 
   if (const auto *I = dyn_cast<Operator>(V))


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