Port to aarch64 (ARM 8).

Continuations don't work yet.

* gc.c (STACK_TOP_EXTRA_WORDS): New macro.
(mark): On aarch64, we must include four words above
the stack top. Some live root pointers sometimes
hide there which are not in any of the callee-saved register
that end up in the machine context via jmp_save.

* jmp.S (jmp_save, jmp_restore): Implement for aarch64.

1 files changed, 35 insertions, 1 deletions

diff --git a/jmp.S b/jmp.S
index 045f1a89..51563636 100644
--- a/jmp.S
+++ b/jmp.S
@@ -33,7 +33,7 @@ _ ## NAME: ;
 #define DEFUN(NAME) \
 .globl _ ## NAME ; \
 _ ## NAME: ;
-#elif __arm__ && !__thumb__
+#elif (__arm__ && !__thumb__) || __aarch64__
 #define DEFUN(NAME) \
 .text ; \
 .align 4 ; \
@@ -295,6 +295,40 @@ DEFUN(jmp_restore)
   mr    %r3, %r4
   blr
 
+#elif __aarch64__
+
+DEFUN(jmp_save)
+  stp x19, x20, [x0, 0]
+  stp x21, x22, [x0, 16]
+  stp x23, x24, [x0, 32]
+  stp x25, x26, [x0, 48]
+  stp x27, x28, [x0, 64]
+  stp x29, x30, [x0, 80]
+  stp d8, d9, [x0, 96]
+  stp d10, d11, [x0, 112]
+  stp d12, d13, [x0, 128]
+  stp d14, d15, [x0, 144]
+  mov x16, sp
+  str x16, [x0, 160]
+  mov w0, #0
+  ret
+
+DEFUN(jmp_restore)
+  ldp x19, x20, [x0, 0]
+  ldp x21, x22, [x0, 16]
+  ldp x23, x24, [x0, 32]
+  ldp x25, x26, [x0, 48]
+  ldp x27, x28, [x0, 64]
+  ldp x29, x30, [x0, 80]
+  ldp d8, d9, [x0, 96]
+  ldp d10, d11, [x0, 112]
+  ldp d12, d13, [x0, 128]
+  ldp d14, d15, [x0, 144]
+  ldr x16, [x0, 160]
+  mov sp, x16
+  mov w0, w1
+  br x30
+
 #else
 #error port me!
 #endif