[APInt] Use lshrInPlace to replace lshr where possible

This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.

This adds an lshrInPlace(const APInt &) version as well.

Differential Revision: https://reviews.llvm.org/D32155

llvm-svn: 300566

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 69484f47223..7ed999fa70b 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -839,7 +839,8 @@ static Value *simplifyX86extrq(IntrinsicInst &II, Value *Op0,
     // Length bits.
     if (CI0) {
       APInt Elt = CI0->getValue();
-      Elt = Elt.lshr(Index).zextOrTrunc(Length);
+      Elt.lshrInPlace(Index);
+      Elt = Elt.zextOrTrunc(Length);
       return LowConstantHighUndef(Elt.getZExtValue());
     }
 
@@ -1036,7 +1037,7 @@ static Value *simplifyX86vpermilvar(const IntrinsicInst &II,
     // The PD variants uses bit 1 to select per-lane element index, so
     // shift down to convert to generic shuffle mask index.
     if (IsPD)
-      Index = Index.lshr(1);
+      Index.lshrInPlace(1);
 
     // The _256 variants are a bit trickier since the mask bits always index
     // into the corresponding 128 half. In order to convert to a generic