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use alloc::{vec, vec::Vec};
use arrayvec::ArrayVec;
use spirv::Word;
use crate::{Handle, UniqueArena};
pub(super) fn bytes_to_words(bytes: &[u8]) -> Vec<Word> {
bytes
.chunks(4)
.map(|chars| chars.iter().rev().fold(0u32, |u, c| (u << 8) | *c as u32))
.collect()
}
pub(super) fn string_to_words(input: &str) -> Vec<Word> {
let bytes = input.as_bytes();
str_bytes_to_words(bytes)
}
pub(super) fn str_bytes_to_words(bytes: &[u8]) -> Vec<Word> {
let mut words = bytes_to_words(bytes);
if bytes.len().is_multiple_of(4) {
// nul-termination
words.push(0x0u32);
}
words
}
/// split a string into chunks and keep utf8 valid
#[allow(unstable_name_collisions)]
pub(super) fn string_to_byte_chunks(input: &str, limit: usize) -> Vec<&[u8]> {
let mut offset: usize = 0;
let mut start: usize = 0;
let mut words = vec![];
while offset < input.len() {
offset = input.floor_char_boundary_polyfill(offset + limit);
// Clippy wants us to call as_bytes() first to avoid the UTF-8 check,
// but we want to assert the output is valid UTF-8.
#[allow(clippy::sliced_string_as_bytes)]
words.push(input[start..offset].as_bytes());
start = offset;
}
words
}
pub(super) const fn map_storage_class(space: crate::AddressSpace) -> spirv::StorageClass {
match space {
crate::AddressSpace::Handle => spirv::StorageClass::UniformConstant,
crate::AddressSpace::Function => spirv::StorageClass::Function,
crate::AddressSpace::Private => spirv::StorageClass::Private,
crate::AddressSpace::Storage { .. } => spirv::StorageClass::StorageBuffer,
crate::AddressSpace::Uniform => spirv::StorageClass::Uniform,
crate::AddressSpace::WorkGroup => spirv::StorageClass::Workgroup,
crate::AddressSpace::Immediate => spirv::StorageClass::PushConstant,
crate::AddressSpace::TaskPayload => spirv::StorageClass::TaskPayloadWorkgroupEXT,
crate::AddressSpace::IncomingRayPayload | crate::AddressSpace::RayPayload => unreachable!(),
}
}
pub(super) fn contains_builtin(
binding: Option<&crate::Binding>,
ty: Handle<crate::Type>,
arena: &UniqueArena<crate::Type>,
built_in: crate::BuiltIn,
) -> bool {
if let Some(&crate::Binding::BuiltIn(bi)) = binding {
bi == built_in
} else if let crate::TypeInner::Struct { ref members, .. } = arena[ty].inner {
members
.iter()
.any(|member| contains_builtin(member.binding.as_ref(), member.ty, arena, built_in))
} else {
false // unreachable
}
}
impl crate::AddressSpace {
pub(super) const fn to_spirv_semantics_and_scope(
self,
) -> (spirv::MemorySemantics, spirv::Scope) {
match self {
Self::Storage { .. } => (spirv::MemorySemantics::empty(), spirv::Scope::Device),
Self::WorkGroup => (spirv::MemorySemantics::empty(), spirv::Scope::Workgroup),
Self::Uniform => (spirv::MemorySemantics::empty(), spirv::Scope::Device),
Self::Handle => (spirv::MemorySemantics::empty(), spirv::Scope::Device),
_ => (spirv::MemorySemantics::empty(), spirv::Scope::Invocation),
}
}
}
/// Return true if the global requires a type decorated with `Block`.
///
/// See [`back::spv::GlobalVariable`] for details.
///
/// [`back::spv::GlobalVariable`]: super::GlobalVariable
pub fn global_needs_wrapper(ir_module: &crate::Module, var: &crate::GlobalVariable) -> bool {
match var.space {
crate::AddressSpace::Uniform
| crate::AddressSpace::Storage { .. }
| crate::AddressSpace::Immediate => {}
_ => return false,
};
match ir_module.types[var.ty].inner {
crate::TypeInner::Struct {
ref members,
span: _,
} => match members.last() {
Some(member) => match ir_module.types[member.ty].inner {
// Structs with dynamically sized arrays can't be copied and can't be wrapped.
crate::TypeInner::Array {
size: crate::ArraySize::Dynamic,
..
} => false,
_ => true,
},
None => false,
},
crate::TypeInner::BindingArray { .. } => false,
// if it's not a structure or a binding array, let's wrap it to be able to put "Block"
_ => true,
}
}
/// Returns true if `pointer` refers to two-row matrix which is a member of a
/// struct in the [`crate::AddressSpace::Uniform`] address space.
pub fn is_uniform_matcx2_struct_member_access(
ir_function: &crate::Function,
fun_info: &crate::valid::FunctionInfo,
ir_module: &crate::Module,
pointer: Handle<crate::Expression>,
) -> bool {
if let crate::TypeInner::Pointer {
base: pointer_base_type,
space: crate::AddressSpace::Uniform,
} = *fun_info[pointer].ty.inner_with(&ir_module.types)
{
if let crate::TypeInner::Matrix {
rows: crate::VectorSize::Bi,
..
} = ir_module.types[pointer_base_type].inner
{
if let crate::Expression::AccessIndex {
base: parent_pointer,
..
} = ir_function.expressions[pointer]
{
if let crate::TypeInner::Pointer {
base: parent_type, ..
} = *fun_info[parent_pointer].ty.inner_with(&ir_module.types)
{
if let crate::TypeInner::Struct { .. } = ir_module.types[parent_type].inner {
return true;
}
}
}
}
}
false
}
///HACK: this is taken from std unstable, remove it when std's floor_char_boundary is stable
/// and available in our msrv.
trait U8Internal {
fn is_utf8_char_boundary_polyfill(&self) -> bool;
}
impl U8Internal for u8 {
fn is_utf8_char_boundary_polyfill(&self) -> bool {
// This is bit magic equivalent to: b < 128 || b >= 192
(*self as i8) >= -0x40
}
}
trait StrUnstable {
fn floor_char_boundary_polyfill(&self, index: usize) -> usize;
}
impl StrUnstable for str {
fn floor_char_boundary_polyfill(&self, index: usize) -> usize {
if index >= self.len() {
self.len()
} else {
let lower_bound = index.saturating_sub(3);
let new_index = self.as_bytes()[lower_bound..=index]
.iter()
.rposition(|b| b.is_utf8_char_boundary_polyfill());
// We know that the character boundary will be within four bytes.
lower_bound + new_index.unwrap()
}
}
}
pub enum BindingDecorations {
BuiltIn(spirv::BuiltIn, ArrayVec<spirv::Decoration, 2>),
Location {
location: u32,
others: ArrayVec<spirv::Decoration, 5>,
/// If this is `Some`, use Decoration::Index with blend_src as an operand
blend_src: Option<Word>,
},
None,
}