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Align to 24 bytes

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nub31
2025-02-03 16:02:15 +01:00
parent c19fa678c8
commit 9feec7f659
2 changed files with 13 additions and 13 deletions
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24
input/baseline/gc.asm
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@@ -16,7 +16,7 @@ gc_init:
ret
gc_alloc:
add rdi, 17 ; add space for metadata
add rdi, 24 ; add space for metadata
mov rdx, [total_alloc_b] ; load total allocations in bytes
cmp rdx, [gc_threshold_b] ; has total exceeded threshold?
jae .collect ; yes? run gc
@@ -35,11 +35,11 @@ gc_alloc:
call sys_mmap ; allocate size + metadata
pop rdi
mov byte [rax], 0 ; set mark to 0
mov qword [rax + 1], rdi ; set total size of object (including metadata)
mov qword [rax + 8], rdi ; set total size of object (including metadata)
mov rsi, [alloc_list] ; load first item in allocation list
mov qword [rax + 9], rsi ; make current head of allocation list the next item in this object
mov qword [rax + 16], rsi ; make current head of allocation list the next item in this object
mov [alloc_list], rax ; update head of allocation list so it points to this object
add rax, 17 ; skip metadata for return value
add rax, 24 ; skip metadata for return value
ret
gc_collect:
@@ -73,17 +73,17 @@ gc_mark:
.loop:
test rsi, rsi ; reached end of list?
jz .done ; yes? return
lea rdx, [rsi + 17]
lea rdx, [rsi + 24]
cmp rdx, rdi ; no? is this the input object?
je .mark_object ; yes? mark it
mov rsi, [rsi + 9] ; no? next item
mov rsi, [rsi + 16] ; no? next item
jmp .loop
.mark_object:
mov al, [rdi] ; load mark
test al, al ; already marked?
jnz .done ; yes? return
mov byte [rdi - 17], 1 ; mark object
mov rcx, [rdi + 1] ; load object size
mov byte [rdi - 24], 1 ; mark object
mov rcx, [rdi + 8] ; load object size
mov rdx, rdi ; start of data
add rcx, rdx ; end of data
.scan_object:
@@ -107,20 +107,20 @@ gc_sweep:
jz .free ; no? free it
mov byte [rdi], 0 ; yes? clear mark for next marking
mov rsi, rdi
mov rdi, [rdi + 9] ; load the next object in the list
mov rdi, [rdi + 16] ; load the next object in the list
jmp .loop ; repeat
.free:
mov rdx, [rdi + 9] ; save address of next object in list
mov rdx, [rdi + 16] ; save address of next object in list
test rsi, rsi
jz .remove_head
mov [rsi + 9], rdx ; unlink the current node by setting the previous node's next to the next node's address
mov [rsi + 16], rdx ; unlink the current node by setting the previous node's next to the next node's address
jmp .free_memory
.remove_head:
mov [alloc_list], rdx ; update head node to be the next node
.free_memory:
push rsi ; save previous node since it will also be the previous node for the next item
push rdx ; save next node
mov rsi, [rdi + 1] ; get length of the object
mov rsi, [rdi + 8] ; get length of the object
sub [total_alloc_b], rsi ; remove this allocation from total allocations
call sys_munmap ; free the memory
pop rdi ; input for next iteration