x86-64: Add alloca.

2009-06-09 03:23:08 +09:00
parent 110a4edc15
commit 8ea8305199
2 changed files with 37 additions and 0 deletions
--- a/lib/alloca86_64.S
+++ b/lib/alloca86_64.S
@ -0,0 +1,33 @@
+/* ---------------------------------------------- */
+/* alloca86_64.S */
+
+#include "../config.h"
+
+.globl alloca
+
+alloca:
+    pop     %rdx
+    mov     %rdi,%rax
+    add     $3,%rax
+    and     $-4,%rax
+    jz      p3
+
+#ifdef TCC_TARGET_PE
+    /* XXX: not tested */
+p1:
+    cmp     $4096,%rax
+    jle     p2
+    sub     $4096,%rsp
+    sub     $4096,%rax
+    test    %rax,(%rsp)
+    jmp p1
+p2:
+#endif
+
+    sub     %rax,%rsp
+    mov     %rsp,%rax
+p3:
+    push    %rdx
+    ret
+
+/* ---------------------------------------------- */