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Auto merge of #80652 - calebzulawski:simd-lanes, r=nagisa
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Improve SIMD type element count validation

Resolves rust-lang/portable-simd#53.

These changes are motivated by `stdsimd` moving in the direction of const generic vectors, e.g.:
```rust
#[repr(simd)]
struct SimdF32<const N: usize>([f32; N]);
```

This makes a few changes:
* Establishes a maximum SIMD lane count of 2^16 (65536).  This value is arbitrary, but attempts to validate lane count before hitting potential errors in the backend.  It's not clear what LLVM's maximum lane count is, but cranelift's appears to be much less than `usize::MAX`, at least.
* Expands some SIMD intrinsics to support arbitrary lane counts.  This resolves the ICE in the linked issue.
* Attempts to catch invalid-sized vectors during typeck when possible.

Unresolved questions:
* Generic-length vectors can't be validated in typeck and are only validated after monomorphization while computing layout.  This "works", but the errors simply bail out with no context beyond the name of the type.  Should these errors instead return `LayoutError` or otherwise provide context in some way?  As it stands, users of `stdsimd` could trivially produce monomorphization errors by making zero-length vectors.

cc `@bjorn3`
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@bors
bors committed Feb 7, 2021
2 parents 9778068 + a4bab7c commit bb587b1
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Showing 28 changed files with 321 additions and 395 deletions.
124 changes: 3 additions & 121 deletions compiler/rustc_codegen_llvm/src/context.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -380,7 +380,7 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
"rust_eh_personality"
};
let fty = self.type_variadic_func(&[], self.type_i32());
self.declare_cfn(name, fty)
self.declare_cfn(name, llvm::UnnamedAddr::Global, fty)
}
};
attributes::apply_target_cpu_attr(self, llfn);
Expand Down Expand Up @@ -429,7 +429,7 @@ impl MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {

fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> {
if self.get_declared_value("main").is_none() {
Some(self.declare_cfn("main", fn_type))
Some(self.declare_cfn("main", llvm::UnnamedAddr::Global, fn_type))
} else {
// If the symbol already exists, it is an error: for example, the user wrote
// #[no_mangle] extern "C" fn main(..) {..}
Expand Down Expand Up @@ -459,8 +459,7 @@ impl CodegenCx<'b, 'tcx> {
} else {
self.type_variadic_func(&[], ret)
};
let f = self.declare_cfn(name, fn_ty);
llvm::SetUnnamedAddress(f, llvm::UnnamedAddr::No);
let f = self.declare_cfn(name, llvm::UnnamedAddr::No, fn_ty);
self.intrinsics.borrow_mut().insert(name, f);
f
}
Expand Down Expand Up @@ -498,25 +497,6 @@ impl CodegenCx<'b, 'tcx> {
let t_f32 = self.type_f32();
let t_f64 = self.type_f64();

macro_rules! vector_types {
($id_out:ident: $elem_ty:ident, $len:expr) => {
let $id_out = self.type_vector($elem_ty, $len);
};
($($id_out:ident: $elem_ty:ident, $len:expr;)*) => {
$(vector_types!($id_out: $elem_ty, $len);)*
}
}
vector_types! {
t_v2f32: t_f32, 2;
t_v4f32: t_f32, 4;
t_v8f32: t_f32, 8;
t_v16f32: t_f32, 16;

t_v2f64: t_f64, 2;
t_v4f64: t_f64, 4;
t_v8f64: t_f64, 8;
}

ifn!("llvm.wasm.trunc.saturate.unsigned.i32.f32", fn(t_f32) -> t_i32);
ifn!("llvm.wasm.trunc.saturate.unsigned.i32.f64", fn(t_f64) -> t_i32);
ifn!("llvm.wasm.trunc.saturate.unsigned.i64.f32", fn(t_f32) -> t_i64);
Expand All @@ -540,149 +520,51 @@ impl CodegenCx<'b, 'tcx> {
ifn!("llvm.sideeffect", fn() -> void);

ifn!("llvm.powi.f32", fn(t_f32, t_i32) -> t_f32);
ifn!("llvm.powi.v2f32", fn(t_v2f32, t_i32) -> t_v2f32);
ifn!("llvm.powi.v4f32", fn(t_v4f32, t_i32) -> t_v4f32);
ifn!("llvm.powi.v8f32", fn(t_v8f32, t_i32) -> t_v8f32);
ifn!("llvm.powi.v16f32", fn(t_v16f32, t_i32) -> t_v16f32);
ifn!("llvm.powi.f64", fn(t_f64, t_i32) -> t_f64);
ifn!("llvm.powi.v2f64", fn(t_v2f64, t_i32) -> t_v2f64);
ifn!("llvm.powi.v4f64", fn(t_v4f64, t_i32) -> t_v4f64);
ifn!("llvm.powi.v8f64", fn(t_v8f64, t_i32) -> t_v8f64);

ifn!("llvm.pow.f32", fn(t_f32, t_f32) -> t_f32);
ifn!("llvm.pow.v2f32", fn(t_v2f32, t_v2f32) -> t_v2f32);
ifn!("llvm.pow.v4f32", fn(t_v4f32, t_v4f32) -> t_v4f32);
ifn!("llvm.pow.v8f32", fn(t_v8f32, t_v8f32) -> t_v8f32);
ifn!("llvm.pow.v16f32", fn(t_v16f32, t_v16f32) -> t_v16f32);
ifn!("llvm.pow.f64", fn(t_f64, t_f64) -> t_f64);
ifn!("llvm.pow.v2f64", fn(t_v2f64, t_v2f64) -> t_v2f64);
ifn!("llvm.pow.v4f64", fn(t_v4f64, t_v4f64) -> t_v4f64);
ifn!("llvm.pow.v8f64", fn(t_v8f64, t_v8f64) -> t_v8f64);

ifn!("llvm.sqrt.f32", fn(t_f32) -> t_f32);
ifn!("llvm.sqrt.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.sqrt.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.sqrt.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.sqrt.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.sqrt.f64", fn(t_f64) -> t_f64);
ifn!("llvm.sqrt.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.sqrt.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.sqrt.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.sin.f32", fn(t_f32) -> t_f32);
ifn!("llvm.sin.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.sin.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.sin.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.sin.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.sin.f64", fn(t_f64) -> t_f64);
ifn!("llvm.sin.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.sin.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.sin.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.cos.f32", fn(t_f32) -> t_f32);
ifn!("llvm.cos.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.cos.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.cos.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.cos.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.cos.f64", fn(t_f64) -> t_f64);
ifn!("llvm.cos.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.cos.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.cos.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.exp.f32", fn(t_f32) -> t_f32);
ifn!("llvm.exp.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.exp.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.exp.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.exp.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.exp.f64", fn(t_f64) -> t_f64);
ifn!("llvm.exp.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.exp.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.exp.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.exp2.f32", fn(t_f32) -> t_f32);
ifn!("llvm.exp2.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.exp2.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.exp2.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.exp2.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.exp2.f64", fn(t_f64) -> t_f64);
ifn!("llvm.exp2.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.exp2.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.exp2.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.log.f32", fn(t_f32) -> t_f32);
ifn!("llvm.log.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.log.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.log.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.log.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.log.f64", fn(t_f64) -> t_f64);
ifn!("llvm.log.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.log.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.log.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.log10.f32", fn(t_f32) -> t_f32);
ifn!("llvm.log10.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.log10.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.log10.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.log10.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.log10.f64", fn(t_f64) -> t_f64);
ifn!("llvm.log10.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.log10.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.log10.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.log2.f32", fn(t_f32) -> t_f32);
ifn!("llvm.log2.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.log2.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.log2.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.log2.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.log2.f64", fn(t_f64) -> t_f64);
ifn!("llvm.log2.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.log2.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.log2.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.fma.f32", fn(t_f32, t_f32, t_f32) -> t_f32);
ifn!("llvm.fma.v2f32", fn(t_v2f32, t_v2f32, t_v2f32) -> t_v2f32);
ifn!("llvm.fma.v4f32", fn(t_v4f32, t_v4f32, t_v4f32) -> t_v4f32);
ifn!("llvm.fma.v8f32", fn(t_v8f32, t_v8f32, t_v8f32) -> t_v8f32);
ifn!("llvm.fma.v16f32", fn(t_v16f32, t_v16f32, t_v16f32) -> t_v16f32);
ifn!("llvm.fma.f64", fn(t_f64, t_f64, t_f64) -> t_f64);
ifn!("llvm.fma.v2f64", fn(t_v2f64, t_v2f64, t_v2f64) -> t_v2f64);
ifn!("llvm.fma.v4f64", fn(t_v4f64, t_v4f64, t_v4f64) -> t_v4f64);
ifn!("llvm.fma.v8f64", fn(t_v8f64, t_v8f64, t_v8f64) -> t_v8f64);

ifn!("llvm.fabs.f32", fn(t_f32) -> t_f32);
ifn!("llvm.fabs.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.fabs.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.fabs.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.fabs.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.fabs.f64", fn(t_f64) -> t_f64);
ifn!("llvm.fabs.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.fabs.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.fabs.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.minnum.f32", fn(t_f32, t_f32) -> t_f32);
ifn!("llvm.minnum.f64", fn(t_f64, t_f64) -> t_f64);
ifn!("llvm.maxnum.f32", fn(t_f32, t_f32) -> t_f32);
ifn!("llvm.maxnum.f64", fn(t_f64, t_f64) -> t_f64);

ifn!("llvm.floor.f32", fn(t_f32) -> t_f32);
ifn!("llvm.floor.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.floor.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.floor.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.floor.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.floor.f64", fn(t_f64) -> t_f64);
ifn!("llvm.floor.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.floor.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.floor.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.ceil.f32", fn(t_f32) -> t_f32);
ifn!("llvm.ceil.v2f32", fn(t_v2f32) -> t_v2f32);
ifn!("llvm.ceil.v4f32", fn(t_v4f32) -> t_v4f32);
ifn!("llvm.ceil.v8f32", fn(t_v8f32) -> t_v8f32);
ifn!("llvm.ceil.v16f32", fn(t_v16f32) -> t_v16f32);
ifn!("llvm.ceil.f64", fn(t_f64) -> t_f64);
ifn!("llvm.ceil.v2f64", fn(t_v2f64) -> t_v2f64);
ifn!("llvm.ceil.v4f64", fn(t_v4f64) -> t_v4f64);
ifn!("llvm.ceil.v8f64", fn(t_v8f64) -> t_v8f64);

ifn!("llvm.trunc.f32", fn(t_f32) -> t_f32);
ifn!("llvm.trunc.f64", fn(t_f64) -> t_f64);
Expand Down
24 changes: 18 additions & 6 deletions compiler/rustc_codegen_llvm/src/declare.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@ fn declare_raw_fn(
cx: &CodegenCx<'ll, '_>,
name: &str,
callconv: llvm::CallConv,
unnamed: llvm::UnnamedAddr,
ty: &'ll Type,
) -> &'ll Value {
debug!("declare_raw_fn(name={:?}, ty={:?})", name, ty);
Expand All @@ -38,9 +39,7 @@ fn declare_raw_fn(
};

llvm::SetFunctionCallConv(llfn, callconv);
// Function addresses in Rust are never significant, allowing functions to
// be merged.
llvm::SetUnnamedAddress(llfn, llvm::UnnamedAddr::Global);
llvm::SetUnnamedAddress(llfn, unnamed);

if cx.tcx.sess.opts.cg.no_redzone.unwrap_or(cx.tcx.sess.target.disable_redzone) {
llvm::Attribute::NoRedZone.apply_llfn(Function, llfn);
Expand Down Expand Up @@ -68,8 +67,13 @@ impl CodegenCx<'ll, 'tcx> {
///
/// If there’s a value with the same name already declared, the function will
/// update the declaration and return existing Value instead.
pub fn declare_cfn(&self, name: &str, fn_type: &'ll Type) -> &'ll Value {
declare_raw_fn(self, name, llvm::CCallConv, fn_type)
pub fn declare_cfn(
&self,
name: &str,
unnamed: llvm::UnnamedAddr,
fn_type: &'ll Type,
) -> &'ll Value {
declare_raw_fn(self, name, llvm::CCallConv, unnamed, fn_type)
}

/// Declare a Rust function.
Expand All @@ -79,7 +83,15 @@ impl CodegenCx<'ll, 'tcx> {
pub fn declare_fn(&self, name: &str, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> &'ll Value {
debug!("declare_rust_fn(name={:?}, fn_abi={:?})", name, fn_abi);

let llfn = declare_raw_fn(self, name, fn_abi.llvm_cconv(), fn_abi.llvm_type(self));
// Function addresses in Rust are never significant, allowing functions to
// be merged.
let llfn = declare_raw_fn(
self,
name,
fn_abi.llvm_cconv(),
llvm::UnnamedAddr::Global,
fn_abi.llvm_type(self),
);
fn_abi.apply_attrs_llfn(self, llfn);
llfn
}
Expand Down

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