ststic arrays and dynamic arrays

stdlib/arr.sl

@@ -0,0 +1,248 @@
+# Dynamic arrays (qword elements)
+#
+# Layout at address `arr`:
+#   [arr + 0]  len   (qword)
+#   [arr + 8]  cap   (qword)
+#   [arr + 16] data  (qword)  = arr + 24
+#   [arr + 24] elements (cap * 8 bytes)
+#
+# Allocation: mmap; free: munmap.
+# Growth: allocate new block, copy elements, munmap old block.
+
+# : arr_new ( cap -- arr )
+:asm arr_new {
+	mov r14, [r12]        ; requested cap
+	cmp r14, 1
+	jge .cap_ok
+	mov r14, 1
+.cap_ok:
+	; bytes = 24 + cap*8
+	mov rsi, r14
+	shl rsi, 3
+	add rsi, 24
+
+	; mmap(NULL, bytes, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0)
+	xor rdi, rdi
+	mov rdx, 3
+	mov r10, 34
+	mov r8, -1
+	xor r9, r9
+	mov rax, 9
+	syscall
+
+	; header
+	mov qword [rax], 0
+	mov [rax + 8], r14
+	lea rbx, [rax + 24]
+	mov [rax + 16], rbx
+
+	; replace cap with arr pointer
+	mov [r12], rax
+	ret
+}
+;
+
+# : arr_len ( arr -- len )
+:asm arr_len {
+	mov rax, [r12]
+	mov rax, [rax]
+	mov [r12], rax
+	ret
+}
+;
+
+# : arr_cap ( arr -- cap )
+:asm arr_cap {
+	mov rax, [r12]
+	mov rax, [rax + 8]
+	mov [r12], rax
+	ret
+}
+;
+
+# : arr_data ( arr -- ptr )
+:asm arr_data {
+	mov rax, [r12]
+	mov rax, [rax + 16]
+	mov [r12], rax
+	ret
+}
+;
+
+# : arr_free ( arr -- )
+:asm arr_free {
+	mov rbx, [r12]        ; base
+	mov rcx, [rbx + 8]    ; cap
+	mov rsi, rcx
+	shl rsi, 3
+	add rsi, 24
+	mov rdi, rbx
+	mov rax, 11
+	syscall
+	add r12, 8            ; drop arr
+	ret
+}
+;
+
+# : arr_reserve ( cap arr -- arr )
+# Ensures capacity >= cap; returns (possibly moved) arr pointer.
+:asm arr_reserve {
+	mov rbx, [r12]        ; arr
+	mov r14, [r12 + 8]    ; requested cap
+	cmp r14, 1
+	jge .req_ok
+	mov r14, 1
+.req_ok:
+	mov rdx, [rbx + 8]    ; old cap
+	cmp rdx, r14
+	jae .no_change
+
+	; alloc new block: bytes = 24 + reqcap*8
+	mov rsi, r14
+	shl rsi, 3
+	add rsi, 24
+	xor rdi, rdi
+	mov rdx, 3
+	mov r10, 34
+	mov r8, -1
+	xor r9, r9
+	mov rax, 9
+	syscall
+
+	mov r10, rax          ; new base
+	lea r9, [r10 + 24]    ; new data
+
+	; header
+	mov r8, [rbx]         ; len
+	mov [r10], r8
+	mov [r10 + 8], r14
+	mov [r10 + 16], r9
+
+	; copy elements from old data
+	mov r11, [rbx + 16]   ; old data
+	xor rcx, rcx          ; i
+.copy_loop:
+	cmp rcx, r8
+	je .copy_done
+	mov rdx, [r11 + rcx*8]
+	mov [r9 + rcx*8], rdx
+	inc rcx
+	jmp .copy_loop
+.copy_done:
+
+	; munmap old block
+	mov rsi, [rbx + 8]
+	shl rsi, 3
+	add rsi, 24
+	mov rdi, rbx
+	mov rax, 11
+	syscall
+
+	; return new arr only
+	mov [r12 + 8], r10
+	add r12, 8
+	ret
+
+.no_change:
+	; drop cap, keep arr
+	mov [r12 + 8], rbx
+	add r12, 8
+	ret
+}
+;
+
+# : arr_push ( x arr -- arr )
+:asm arr_push {
+	mov rbx, [r12]        ; arr
+	mov rcx, [rbx]        ; len
+	mov rdx, [rbx + 8]    ; cap
+	cmp rcx, rdx
+	jb .have_space
+
+	; grow: newcap = max(1, cap) * 2
+	mov r14, rdx
+	cmp r14, 1
+	jae .cap_ok
+	mov r14, 1
+.cap_ok:
+	shl r14, 1
+
+	; alloc new block
+	mov rsi, r14
+	shl rsi, 3
+	add rsi, 24
+	xor rdi, rdi
+	mov rdx, 3
+	mov r10, 34
+	mov r8, -1
+	xor r9, r9
+	mov rax, 9
+	syscall
+
+	mov r10, rax          ; new base
+	lea r9, [r10 + 24]    ; new data
+
+	; header
+	mov rcx, [rbx]        ; len (reload; syscall clobbers rcx)
+	mov [r10], rcx
+	mov [r10 + 8], r14
+	mov [r10 + 16], r9
+
+	; copy old data
+	mov r11, [rbx + 16]   ; old data
+	xor r8, r8
+.push_copy_loop:
+	cmp r8, rcx
+	je .push_copy_done
+	mov rdx, [r11 + r8*8]
+	mov [r9 + r8*8], rdx
+	inc r8
+	jmp .push_copy_loop
+.push_copy_done:
+
+	; munmap old block
+	mov rsi, [rbx + 8]
+	shl rsi, 3
+	add rsi, 24
+	mov rdi, rbx
+	mov rax, 11
+	syscall
+
+	; switch to new base
+	mov rbx, r10
+
+.have_space:
+	; store element at data[len]
+	mov r9, [rbx + 16]
+	mov rax, [r12 + 8]    ; x
+	mov rcx, [rbx]        ; len
+	mov [r9 + rcx*8], rax
+	inc rcx
+	mov [rbx], rcx
+
+	; return arr only
+	mov [r12 + 8], rbx
+	add r12, 8
+	ret
+}
+;
+
+# : arr_pop ( arr -- x arr )
+:asm arr_pop {
+	mov rbx, [r12]        ; arr
+	mov rcx, [rbx]        ; len
+	test rcx, rcx
+	jz .empty
+	dec rcx
+	mov [rbx], rcx
+	mov rdx, [rbx + 16]   ; data
+	mov rax, [rdx + rcx*8]
+	jmp .push
+.empty:
+	xor rax, rax
+.push:
+	sub r12, 8
+	mov [r12], rax
+	ret
+}
+;