Clean up x86 support code

vm/cpu-x86.32.S

@@ -0,0 +1,45 @@
+#include "asm.h"
+
+/* Note that primitive word definitions are compiled with
+__attribute__((regparm 2), so the pointer to the word object is passed in EAX,
+and the callstack top is passed in EDX */
+
+#define ARG0 %eax
+#define ARG1 %edx
+#define XT_REG %ecx
+#define STACK_REG %esp
+#define DS_REG %edi
+
+#define CELL_SIZE 4
+
+#define PUSH_NONVOLATILE \
+	push %ebx \
+	push %ebp
+
+#define POP_NONVOLATILE \
+	pop %ebp \
+	pop %ebx
+
+#define QUOT_XT_OFFSET 5
+#define PROFILING_OFFSET 25
+#define WORD_DEF_OFFSET 13
+#define WORD_XT_OFFSET 29
+
+/* We pass a function pointer to memcpy in 16(%esp) to work around a Mac OS X
+ABI limitation which would otherwise require us to do a bizzaro PC-relative
+trampoline to retrieve the function address */
+DEF(void,set_callstack,(F_STACK_FRAME *to, F_STACK_FRAME *from, CELL length, void *memcpy)):
+	mov 4(%esp),%ebp                   /* to */
+	mov 8(%esp),%edx                   /* from */
+	mov 12(%esp),%ecx                  /* length */
+	mov 16(%esp),%eax                  /* memcpy */
+	sub %ecx,%ebp                      /* compute new stack pointer */
+	mov %ebp,%esp
+	push %ecx                          /* pass length */
+	push %edx                          /* pass src */
+	push %ebp                          /* pass dst */
+	call *%eax                         /* call memcpy */
+	add $12,%esp                       /* pop args from the stack */
+	ret                                /* return _with new stack_ */
+
+#include "cpu-x86.S"

vm/cpu-x86.32.h

@@ -0,0 +1,8 @@
+#define FACTOR_CPU_STRING "x86.32"
+
+register CELL ds asm("esi");
+register CELL rs asm("edi");
+
+#define FASTCALL __attribute__ ((regparm (2)))
+
+void set_callstack(F_STACK_FRAME *to, F_STACK_FRAME *from, CELL length, void *memcpy);

vm/cpu-x86.64.S

@@ -0,0 +1,41 @@
+#include "asm.h"
+
+#define ARG0 %rdi
+#define ARG1 %rsi
+#define XT_REG %rcx
+#define STACK_REG %rsp
+#define DS_REG %r14
+
+#define CELL_SIZE 8
+
+#define PUSH_NONVOLATILE \
+	push %rbx \
+	push %rbp \
+	push %r12 \
+	push %r13 \
+	push %r16 \
+	push %rax                          /* Alignment */
+
+#define POP_NONVOLATILE \
+	pop %rax                           /* Alignment */ \
+	pop %r16 \
+	pop %r13 \
+	pop %r12 \
+	pop %rbp \
+	pop %rbx
+
+#define QUOT_XT_OFFSET 13
+#define PROFILING_OFFSET 53
+#define WORD_DEF_OFFSET 29
+#define WORD_XT_OFFSET 61
+
+/* We pass a function pointer to memcpy in 16(%esp) to work around a Mac OS X
+ABI limitation which would otherwise require us to do a bizzaro PC-relative
+trampoline to retrieve the function address */
+DEF(void,set_callstack,(F_STACK_FRAME *to, F_STACK_FRAME *from, CELL length, void *memcpy)):
+	sub %rdx,%rdi                      /* compute new stack pointer */
+	mov %rdi,%rsp
+	call *%rcx                         /* call memcpy */
+	ret                                /* return _with new stack_ */
+
+#include "cpu-x86.S"

vm/cpu-x86.64.h

@@ -0,0 +1,6 @@
+#define FACTOR_CPU_STRING "x86.64"
+
+register CELL ds asm("r14");
+register CELL rs asm("r15");
+
+#define FASTCALL