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Use vector icmp in simd_cmp! when possible

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bjorn3 2020-03-27 16:41:05 +01:00
parent 3f33fcbd30
commit d2c5b4be68
1 changed files with 29 additions and 0 deletions
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29
src/intrinsics/mod.rs
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@ -154,6 +154,21 @@ fn lane_type_and_count<'tcx>(
(lane_layout, lane_count)
}
fn clif_vector_type<'tcx>(tcx: TyCtxt<'tcx>, layout: TyLayout<'tcx>) -> Option<Type> {
let (element, count) = match &layout.abi {
Abi::Vector { element, count } => (element.clone(), *count),
_ => unreachable!(),
};
match scalar_to_clif_type(tcx, element).by(u16::try_from(count).unwrap()) {
// Cranelift currently only implements icmp for 128bit vectors. While 64bit lanes are
// supported, this needs either the `use_sse41_simd` or `use_sse42_simd` target flag
// to be enabled.
Some(vector_ty) if vector_ty.bits() == 128 && vector_ty.lane_type() != types::I64 => Some(vector_ty),
_ => None,
}
}
fn simd_for_each_lane<'tcx, B: Backend>(
fx: &mut FunctionCx<'_, 'tcx, B>,
val: CValue<'tcx>,
@ -237,6 +252,18 @@ fn bool_to_zero_or_max_uint<'tcx>(
macro simd_cmp {
($fx:expr, $cc:ident($x:ident, $y:ident) -> $ret:ident) => {
let vector_ty = clif_vector_type($fx.tcx, $x.layout());
if let Some(vector_ty) = vector_ty {
let x = $x.load_scalar($fx);
let y = $y.load_scalar($fx);
let val = codegen_icmp($fx, IntCC::$cc, x, y);
// HACK This depends on the fact that icmp for vectors represents bools as 0 and !0, not 0 and 1.
let val = $fx.bcx.ins().raw_bitcast(vector_ty, val);
$ret.write_cvalue($fx, CValue::by_val(val, $ret.layout()));
} else {
simd_pair_for_each_lane(
$fx,
$x,
@ -250,8 +277,10 @@ macro simd_cmp {
bool_to_zero_or_max_uint(fx, res_lane_layout, res_lane)
},
);
}
},
($fx:expr, $cc_u:ident|$cc_s:ident($x:ident, $y:ident) -> $ret:ident) => {
// FIXME use vector icmp when possible
simd_pair_for_each_lane(
$fx,
$x,