From 033aaaf45157459983ea283275dd0df348eafc8d Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sat, 13 May 2006 02:16:08 +0000
Subject: [PATCH] Add/Sub/Mul are safe to promote here as well.  Incrementing a
 single-bit bitfield now gives this code:

_plus:
        lwz r2, 0(r3)
        rlwimi r2, r2, 0, 1, 31
        xoris r2, r2, 32768
        stw r2, 0(r3)
        blr

instead of this:

_plus:
        lwz r2, 0(r3)
        srwi r4, r2, 31
        slwi r4, r4, 31
        addis r4, r4, -32768
        rlwimi r2, r4, 0, 0, 0
        stw r2, 0(r3)
        blr

this can obviously still be improved.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28275 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/InstructionCombining.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index f25ac97ef5c..99a000fa926 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -4793,6 +4793,9 @@ static bool CanEvaluateInDifferentType(Value *V, const Type *Ty,
   if (!I || !I->hasOneUse()) return false;
   
   switch (I->getOpcode()) {
+  case Instruction::Add:
+  case Instruction::Sub:
+  case Instruction::Mul:
   case Instruction::And:
   case Instruction::Or:
   case Instruction::Xor:
@@ -4824,6 +4827,9 @@ Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty) {
   Instruction *I = cast<Instruction>(V);
   Instruction *Res;
   switch (I->getOpcode()) {
+  case Instruction::Add:
+  case Instruction::Sub:
+  case Instruction::Mul:
   case Instruction::And:
   case Instruction::Or:
   case Instruction::Xor: {
-- 
2.34.1