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.

llvm-svn: 28275
This commit is contained in:
Chris Lattner 2006-05-13 02:16:08 +00:00
parent 69a0ce6261
commit 3987a8532d
1 changed files with 6 additions and 0 deletions

View File

@ -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: {