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* add the shladd instruction 

* fold left shifts of 1, 2, 3 or 4 bits into adds

  This doesn't save much now, but should get a serious workout once
  multiplies by constants get converted to shift/add/sub sequences.
  Hold on! :)

llvm-svn: 21282
This commit is contained in:
Duraid Madina 2005-04-13 06:12:04 +00:00
parent c7287c8eda
commit 2f2312575b
2 changed files with 23 additions and 0 deletions
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20
llvm/lib/Target/IA64/IA64ISelPattern.cpp
View File

@ -873,6 +873,26 @@ assert(0 && "hmm, ISD::SIGN_EXTEND: shouldn't ever be reached. bad luck!\n");
BuildMI(BB, IA64::FMA, 3, Result).addReg(Tmp1).addReg(Tmp2).addReg(Tmp3);
return Result; // early exit
}
if(DestType != MVT::f64 && N.getOperand(0).getOpcode() == ISD::SHL &&
N.getOperand(0).Val->hasOneUse()) { // if we might be able to fold
// this add into a shladd, try:
ConstantSDNode *CSD = NULL;
if((CSD = dyn_cast<ConstantSDNode>(N.getOperand(0).getOperand(1))) &&
(CSD->getValue() >= 1) && (CSD->getValue() <= 4) ) { // we can:
// ++FusedSHLADD; // Statistic
Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
int shl_amt = CSD->getValue();
Tmp3 = SelectExpr(N.getOperand(1));
BuildMI(BB, IA64::SHLADD, 3, Result)
.addReg(Tmp1).addImm(shl_amt).addReg(Tmp3);
return Result; // early exit
}
}
//else, fallthrough:
Tmp1 = SelectExpr(N.getOperand(0));
if(DestType != MVT::f64) { // integer addition:
switch (ponderIntegerAdditionWith(N.getOperand(1), Tmp3)) {

3
llvm/lib/Target/IA64/IA64InstrInfo.td
View File

@ -111,6 +111,9 @@ def SHRS : AForm<0x03, 0x0b, (ops GR:$dst, GR:$src1, GR:$src2),
def SHRSI : AForm<0x03, 0x0b, (ops GR:$dst, GR:$src1, u6imm:$imm),
"shr $dst = $src1, $imm;;">;
def SHLADD : AForm<0x03, 0x0b, (ops GR:$dst, GR:$src1, u6imm:$imm, GR:$src2),
"shladd $dst = $src1, $imm, $src2;;">;
def EXTRU : AForm<0x03, 0x0b, (ops GR:$dst, GR:$src1, u6imm:$imm1, u6imm:$imm2),
"extr.u $dst = $src1, $imm1, $imm2;;">;