From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Sun, 18 Aug 2019 12:26:33 +0000 (+0000)
Subject: [InstCombine] Cherry-pick NFC cleanups of foldShiftIntoShiftInAnotherHandOfAndInICmp... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=34e84970cc9a1cb843274d4007cae9451f1a4df6;p=llvm

[InstCombine] Cherry-pick NFC cleanups of foldShiftIntoShiftInAnotherHandOfAndInICmp() from D66383

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369207 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index babbd9df908..620b5563804 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -3321,12 +3321,15 @@ foldShiftIntoShiftInAnotherHandOfAndInICmp(ICmpInst &I, const SimplifyQuery SQ,
                                m_Instruction(MaybeTruncation)))))
     return nullptr;
 
-  Instruction *UntruncatedShift = XShift;
-
   // We potentially looked past 'trunc', but only when matching YShift,
   // therefore YShift must have the widest type.
-  Type *WidestTy = YShift->getType();
-  assert(XShift->getType() == I.getOperand(0)->getType() &&
+  Instruction *WidestShift = YShift;
+  // Therefore XShift must have the shallowest type.
+  // Or they both have identical types if there was no truncation.
+  Instruction *NarrowestShift = XShift;
+
+  Type *WidestTy = WidestShift->getType();
+  assert(NarrowestShift->getType() == I.getOperand(0)->getType() &&
          "We did not look past any shifts while matching XShift though.");
   bool HadTrunc = WidestTy != I.getOperand(0)->getType();
 
@@ -3363,7 +3366,7 @@ foldShiftIntoShiftInAnotherHandOfAndInICmp(ICmpInst &I, const SimplifyQuery SQ,
       // Due to the 'trunc', we will need to widen X. For that either the old
       // 'trunc' or the shift amt in the non-truncated shift should be one-use.
       if (!MaybeTruncation->hasOneUse() &&
-          !UntruncatedShift->getOperand(1)->hasOneUse())
+          !NarrowestShift->getOperand(1)->hasOneUse())
         return nullptr;
     }
   }