[PATCH] D36561: [InstCombine] Move the checks for pointer types in getMaskedTypeForICmpPair earlier in the function

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.

I don't think there's any reason to have them scattered about and on all 4 operands. We already have an early check that both compares must be the same type. And within a given compare the LHS and RHS must have the same type. Beyond that I don't think there's anyway this function returns anything valid for pointer types. So let's just return early and be done with it.


https://reviews.llvm.org/D36561

Files:
  lib/Transforms/InstCombine/InstCombineAndOrXor.cpp


Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -302,8 +302,8 @@
                                          ICmpInst::Predicate &PredR) {
   if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType())
     return 0;
-  // vectors are not (yet?) supported
-  if (LHS->getOperand(0)->getType()->isVectorTy())
+  // vectors are not (yet?) supported. Don't support pointers either.
+  if (!LHS->getOperand(0)->getType()->isIntegerTy())
     return 0;
 
   // Here comes the tricky part:
@@ -320,20 +320,14 @@
     L21 = L22 = L1 = nullptr;
   } else {
     // Look for ANDs in the LHS icmp.
-    if (!L1->getType()->isIntegerTy()) {
-      // You can icmp pointers, for example. They really aren't masks.
-      L11 = L12 = nullptr;
-    } else if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) {
+    if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) {
       // Any icmp can be viewed as being trivially masked; if it allows us to
       // remove one, it's worth it.
       L11 = L1;
       L12 = Constant::getAllOnesValue(L1->getType());
     }
 
-    if (!L2->getType()->isIntegerTy()) {
-      // You can icmp pointers, for example. They really aren't masks.
-      L21 = L22 = nullptr;
-    } else if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) {
+    if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) {
       L21 = L2;
       L22 = Constant::getAllOnesValue(L2->getType());
     }
@@ -360,7 +354,7 @@
     E = R2;
     R1 = nullptr;
     Ok = true;
-  } else if (R1->getType()->isIntegerTy()) {
+  } else {
     if (!match(R1, m_And(m_Value(R11), m_Value(R12)))) {
       // As before, model no mask as a trivial mask if it'll let us do an
       // optimization.
@@ -386,7 +380,7 @@
     return 0;
 
   // Look for ANDs on the right side of the RHS icmp.
-  if (!Ok && R2->getType()->isIntegerTy()) {
+  if (!Ok) {
     if (!match(R2, m_And(m_Value(R11), m_Value(R12)))) {
       R11 = R2;
       R12 = Constant::getAllOnesValue(R2->getType());


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