Method const_fold_load

crates/rustc_codegen_spirv/src/builder_spirv.rs:79–103

(self, cx: &CodegenCx<'_>)

impl SpirvValue {
    pub fn const_fold_load(self, cx: &CodegenCx<'_>) -> Option<Self> {
        match self.kind {
            SpirvValueKind::Def(id) | SpirvValueKind::IllegalConst(id) => {
                let &entry = cx.builder.id_to_const.borrow().get(&id)?;
                match entry.val {
                    SpirvConst::PtrTo { pointee } => {
                        let ty = match cx.lookup_type(self.ty) {
                            SpirvType::Pointer { pointee } => pointee,
                            ty => bug!("load called on value that wasn't a pointer: {:?}", ty),
                        };
                        // FIXME(eddyb) deduplicate this `if`-`else` and its other copies.
                        let kind = if entry.legal.is_ok() {
                            SpirvValueKind::Def(pointee)
                        } else {
                            SpirvValueKind::IllegalConst(pointee)
                        };
                        Some(SpirvValue { kind, ty })
                    }
                    _ => None,
                }
            }

            _ => None,
        }
    }

    // Important: we *cannot* use bx.emit() here, because this is called in
    // contexts where the emitter is already locked. Doing so may cause subtle