mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-18 12:29:21 +00:00
Simplify code
Implement InstCombine/mul.ll:test9 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8488 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
53dce0c43f
commit
515c97c230
@ -527,17 +527,14 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) {
|
||||
return BinaryOperator::create(Instruction::Mul, SI->getOperand(0),
|
||||
*CI << *ShOp);
|
||||
|
||||
const Type *Ty = CI->getType();
|
||||
int64_t Val = (int64_t)cast<ConstantInt>(CI)->getRawValue();
|
||||
switch (Val) {
|
||||
case -1: // X * -1 -> -X
|
||||
if (CI->isNullValue())
|
||||
return ReplaceInstUsesWith(I, Op1); // X * 0 == 0
|
||||
if (CI->equalsInt(1)) // X * 1 == X
|
||||
return ReplaceInstUsesWith(I, Op0);
|
||||
if (CI->isAllOnesValue()) // X * -1 == 0 - X
|
||||
return BinaryOperator::createNeg(Op0, I.getName());
|
||||
case 0:
|
||||
return ReplaceInstUsesWith(I, Op1); // Eliminate 'mul double %X, 0'
|
||||
case 1:
|
||||
return ReplaceInstUsesWith(I, Op0); // Eliminate 'mul int %X, 1'
|
||||
}
|
||||
|
||||
int64_t Val = (int64_t)cast<ConstantInt>(CI)->getRawValue();
|
||||
if (uint64_t C = Log2(Val)) // Replace X*(2^C) with X << C
|
||||
return new ShiftInst(Instruction::Shl, Op0,
|
||||
ConstantUInt::get(Type::UByteTy, C));
|
||||
|
Loading…
Reference in New Issue
Block a user