Method emit_compute_memory_size

winch/codegen/src/codegen/mod.rs:1525–1541

Retrieves the size of the memory, pushing the result to the value stack.

(&mut self, heap_data: &HeapData)

    /// Retrieves the size of the memory, pushing the result to the value stack.
    pub fn emit_compute_memory_size(&mut self, heap_data: &HeapData) -> Result<()> {
        let size_reg = self.context.any_gpr(self.masm)?;
        self.load_memory_length(heap_data, size_reg)?;

        // Emit a shift to get the size in pages rather than in bytes.
        let dst = TypedReg::new(heap_data.index_type(), size_reg);
        let pow = heap_data.memory.page_size_log2;
        self.masm.shift_ir(
            writable!(dst.reg),
            Imm::i32(pow as i32),
            dst.into(),
            ShiftKind::ShrU,
            self.env.ptr_type().try_into()?,
        )?;
        self.context.stack.push(dst.into());
        Ok(())
    }

    /// Emit a bounds check for `ptr+len` and put the native address for this
    /// wasm address into `dst`.