change allocate/deallocate to use rewritable code instead of code poi…

…nter
devyn · Aug 9, 2023 · d6e5312 · d6e5312
1 parent 5e64ba8
commit d6e5312
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Showing 3 changed files with 13 additions and 25 deletions.
diff --git a/stage1/memory.s b/stage1/memory.s
@@ -11,14 +11,6 @@
 
 .bss
 
-.align 3
-.global ALLOCATE
-ALLOCATE: .skip 8 # builtin_allocate
-
-.align 3
-.global DEALLOCATE
-DEALLOCATE: .skip 8 # builtin_deallocate
-
 .align 3
 .global BUILTIN_HEAP_PTR
 BUILTIN_HEAP_PTR: .skip 8 # _heap_start
@@ -41,32 +33,28 @@ _object_region_start: .skip 0xc0000 # 768 KiB
 
 .text
 
+# rewritable with up to 6 instructions
 # args: a0 = bytes to allocate, a1 = alignment
 # ret: a0 = pointer on success, zero on failure
 .global allocate
 allocate:
-        ld t0, (ALLOCATE)
-        jalr zero, (t0)
+        jal zero, builtin_allocate
+        .skip 5 * 4
 
+# rewritable with up to 6 instructions
 # args: a0 = pointer, a1 = number of bytes
 # ret: a0 = 0
 .global deallocate
 deallocate:
-        ld t0, (DEALLOCATE)
-        jalr zero, (t0)
+        jal zero, builtin_deallocate
+        .skip 5 * 4
 
 .global memory_init
 memory_init:
         addi sp, sp, -0x10
         sd ra, 0x00(sp)
         sd s1, 0x08(sp)
         # initialize globals
-        la t1, builtin_allocate
-        la t2, ALLOCATE
-        sd t1, (t2)
-        la t1, builtin_deallocate
-        la t2, DEALLOCATE
-        sd t1, (t2)
         la t1, _heap_start
         la t2, BUILTIN_HEAP_PTR
         sd t1, (t2)

diff --git a/stage1/words.s b/stage1/words.s
@@ -134,16 +134,16 @@ INITIAL_WORDS:
         .ascii "eval"
         .balign 8
 
-        .quad ALLOCATE
-        .2byte 10
+        .quad allocate
+        .2byte 9
         .byte LISP_OBJECT_TYPE_INTEGER
-        .ascii "allocate$$"
+        .ascii "allocate$"
         .balign 8
 
-        .quad DEALLOCATE
-        .2byte 12
+        .quad deallocate
+        .2byte 11
         .byte LISP_OBJECT_TYPE_INTEGER
-        .ascii "deallocate$$"
+        .ascii "deallocate$"
         .balign 8
 
         .quad define

diff --git a/stage2.lsp b/stage2.lsp
@@ -16,7 +16,7 @@
 ; (allocate <size> <align>)
 (define allocate (proc args scope
   (car
-    (call-native (peek.d allocate$$)
+    (call-native allocate$
       (eval scope (car args))
       (eval scope (cadr args))))))