From: Fangrui Song <maskray@google.com>
Date: Mon, 8 Apr 2019 07:29:24 +0000 (+0000)
Subject: [ConstantRange] Delete redundnt {z,s}extOrSelf for multiplication
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e866cff2107a190cb39ab4af19e3ce17b217fafe;p=llvm

[ConstantRange] Delete redundnt {z,s}extOrSelf for multiplication

These calls are redundant because the quotients have the same BitWidth
as MinValue/MaxValue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357886 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/IR/ConstantRange.cpp b/lib/IR/ConstantRange.cpp
index f48fe9f737d..391d9653db5 100644
--- a/lib/IR/ConstantRange.cpp
+++ b/lib/IR/ConstantRange.cpp
@@ -314,13 +314,6 @@ ConstantRange::makeGuaranteedNoWrapRegion(Instruction::BinaryOps BinOp,
         Lower = APIntOps::RoundingSDiv(MinValue, V, APInt::Rounding::UP);
         Upper = APIntOps::RoundingSDiv(MaxValue, V, APInt::Rounding::DOWN);
       }
-      if (Unsigned) {
-        Lower = Lower.zextOrSelf(BitWidth);
-        Upper = Upper.zextOrSelf(BitWidth);
-      } else {
-        Lower = Lower.sextOrSelf(BitWidth);
-        Upper = Upper.sextOrSelf(BitWidth);
-      }
       // ConstantRange ctor take a half inclusive interval [Lower, Upper + 1).
       // Upper + 1 is guanranteed not to overflow, because |divisor| > 1. 0, -1,
       // and 1 are already handled as special cases.