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Rollup merge of #92425 - calebzulawski:simd-cast, r=workingjubilee

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Improve SIMD casts

* Allows `simd_cast` intrinsic to take `usize` and `isize`
* Adds `simd_as` intrinsic, which is the same as `simd_cast` except for saturating float-to-int conversions (matching the behavior of `as`).

cc `@workingjubilee`
This commit is contained in:
Matthias Krüger 2022-01-18 22:00:45 +01:00 • committed by GitHub
commit 7889f96103
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GPG key ID: 4AEE18F83AFDEB23
8 changed files with 314 additions and 177 deletions
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59
compiler/rustc_codegen_llvm/src/builder.rs
View file

@ -731,27 +731,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
}
fn fptoui_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
if !self.fptoint_sat_broken_in_llvm() {
let src_ty = self.cx.val_ty(val);
let float_width = self.cx.float_width(src_ty);
let int_width = self.cx.int_width(dest_ty);
let name = format!("llvm.fptoui.sat.i{}.f{}", int_width, float_width);
return Some(self.call_intrinsic(&name, &[val]));
}
None
self.fptoint_sat(false, val, dest_ty)
}
fn fptosi_sat(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> Option<&'ll Value> {
if !self.fptoint_sat_broken_in_llvm() {
let src_ty = self.cx.val_ty(val);
let float_width = self.cx.float_width(src_ty);
let int_width = self.cx.int_width(dest_ty);
let name = format!("llvm.fptosi.sat.i{}.f{}", int_width, float_width);
return Some(self.call_intrinsic(&name, &[val]));
}
None
self.fptoint_sat(true, val, dest_ty)
}
fn fptoui(&mut self, val: &'ll Value, dest_ty: &'ll Type) -> &'ll Value {
@ -1455,4 +1439,43 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
_ => false,
}
}
fn fptoint_sat(
&mut self,
signed: bool,
val: &'ll Value,
dest_ty: &'ll Type,
) -> Option<&'ll Value> {
if !self.fptoint_sat_broken_in_llvm() {
let src_ty = self.cx.val_ty(val);
let (float_ty, int_ty, vector_length) = if self.cx.type_kind(src_ty) == TypeKind::Vector
{
assert_eq!(self.cx.vector_length(src_ty), self.cx.vector_length(dest_ty));
(
self.cx.element_type(src_ty),
self.cx.element_type(dest_ty),
Some(self.cx.vector_length(src_ty)),
)
} else {
(src_ty, dest_ty, None)
};
let float_width = self.cx.float_width(float_ty);
let int_width = self.cx.int_width(int_ty);
let instr = if signed { "fptosi" } else { "fptoui" };
let name = if let Some(vector_length) = vector_length {
format!(
"llvm.{}.sat.v{}i{}.v{}f{}",
instr, vector_length, int_width, vector_length, float_width
)
} else {
format!("llvm.{}.sat.i{}.f{}", instr, int_width, float_width)
};
let f =
self.declare_cfn(&name, llvm::UnnamedAddr::No, self.type_func(&[src_ty], dest_ty));
Some(self.call(self.type_func(&[src_ty], dest_ty), f, &[val], None))
} else {
None
}
}
}

30
compiler/rustc_codegen_llvm/src/intrinsic.rs
View file

@ -1688,7 +1688,7 @@ unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#,
bitwise_red!(simd_reduce_all: vector_reduce_and, true);
bitwise_red!(simd_reduce_any: vector_reduce_or, true);
if name == sym::simd_cast {
if name == sym::simd_cast || name == sym::simd_as {
require_simd!(ret_ty, "return");
let (out_len, out_elem) = ret_ty.simd_size_and_type(bx.tcx());
require!(
@ -1714,14 +1714,26 @@ unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#,
let (in_style, in_width) = match in_elem.kind() {
// vectors of pointer-sized integers should've been
// disallowed before here, so this unwrap is safe.
ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()),
ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()),
ty::Int(i) => (
Style::Int(true),
i.normalize(bx.tcx().sess.target.pointer_width).bit_width().unwrap(),
),
ty::Uint(u) => (
Style::Int(false),
u.normalize(bx.tcx().sess.target.pointer_width).bit_width().unwrap(),
),
ty::Float(f) => (Style::Float, f.bit_width()),
_ => (Style::Unsupported, 0),
};
let (out_style, out_width) = match out_elem.kind() {
ty::Int(i) => (Style::Int(true), i.bit_width().unwrap()),
ty::Uint(u) => (Style::Int(false), u.bit_width().unwrap()),
ty::Int(i) => (
Style::Int(true),
i.normalize(bx.tcx().sess.target.pointer_width).bit_width().unwrap(),
),
ty::Uint(u) => (
Style::Int(false),
u.normalize(bx.tcx().sess.target.pointer_width).bit_width().unwrap(),
),
ty::Float(f) => (Style::Float, f.bit_width()),
_ => (Style::Unsupported, 0),
};
@ -1748,10 +1760,10 @@ unsupported {} from `{}` with element `{}` of size `{}` to `{}`"#,
});
}
(Style::Float, Style::Int(out_is_signed)) => {
return Ok(if out_is_signed {
bx.fptosi(args[0].immediate(), llret_ty)
} else {
bx.fptoui(args[0].immediate(), llret_ty)
return Ok(match (out_is_signed, name == sym::simd_as) {
(false, false) => bx.fptoui(args[0].immediate(), llret_ty),
(true, false) => bx.fptosi(args[0].immediate(), llret_ty),
(_, true) => bx.cast_float_to_int(out_is_signed, args[0].immediate(), llret_ty),
});
}
(Style::Float, Style::Float) => {