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Remove shl/shr special handling for 128bit ints

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Cranelift now natively supports 128bit int shifting
This commit is contained in:
bjorn3 2021-07-05 18:02:12 +02:00
parent 17eaf432b7
commit f7cfb9d6d5
1 changed files with 1 additions and 38 deletions
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39
src/codegen_i128.rs
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@ -19,9 +19,6 @@ pub(crate) fn maybe_codegen<'tcx>(
return None;
}
let lhs_val = lhs.load_scalar(fx);
let rhs_val = rhs.load_scalar(fx);
let is_signed = type_sign(lhs.layout().ty);
match bin_op {
@ -128,40 +125,6 @@ pub(crate) fn maybe_codegen<'tcx>(
assert!(!checked);
None
}
BinOp::Shl | BinOp::Shr => {
let is_overflow = if checked {
// rhs >= 128
// FIXME support non 128bit rhs
/*let (rhs_lsb, rhs_msb) = fx.bcx.ins().isplit(rhs_val);
let rhs_msb_gt_0 = fx.bcx.ins().icmp_imm(IntCC::NotEqual, rhs_msb, 0);
let rhs_lsb_ge_128 = fx.bcx.ins().icmp_imm(IntCC::SignedGreaterThan, rhs_lsb, 127);
let is_overflow = fx.bcx.ins().bor(rhs_msb_gt_0, rhs_lsb_ge_128);*/
let is_overflow = fx.bcx.ins().bconst(types::B1, false);
Some(fx.bcx.ins().bint(types::I8, is_overflow))
} else {
None
};
let truncated_rhs = clif_intcast(fx, rhs_val, types::I32, false);
let val = match bin_op {
BinOp::Shl => fx.bcx.ins().ishl(lhs_val, truncated_rhs),
BinOp::Shr => {
if is_signed {
fx.bcx.ins().sshr(lhs_val, truncated_rhs)
} else {
fx.bcx.ins().ushr(lhs_val, truncated_rhs)
}
}
_ => unreachable!(),
};
if let Some(is_overflow) = is_overflow {
let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter());
Some(CValue::by_val_pair(val, is_overflow, fx.layout_of(out_ty)))
} else {
Some(CValue::by_val(val, lhs.layout()))
}
}
BinOp::Shl | BinOp::Shr => None,
}
}