2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
5 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
6 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
8 * Permission is hereby granted to use or copy this program
9 * for any purpose, provided the above notices are retained on all copies.
10 * Permission to modify the code and to distribute modified code is granted,
11 * provided the above notices are retained, and a notice that the code was
12 * modified is included with the above copyright notice.
14 /* Boehm, November 17, 1995 12:13 pm PST */
18 # include "private/gc_priv.h"
21 # if defined(OS2) || defined(CX_UX)
22 # define _setjmp(b) setjmp(b)
23 # define _longjmp(b,v) longjmp(b,v)
29 # include <machine/reg.h>
33 #if defined(__MWERKS__) && !defined(POWERPC)
35 asm static void PushMacRegisters()
37 sub.w #4,sp // reserve space for one parameter.
44 # if !__option(a6frames)
45 // <pcb> perhaps a6 should be pushed if stack frames are not being used.
49 // skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
62 add.w #4,sp // fix stack.
66 #endif /* __MWERKS__ */
68 # if defined(SPARC) || defined(IA64)
69 /* Value returned from register flushing routine; either sp (SPARC) */
70 /* or ar.bsp (IA64) */
71 ptr_t GC_save_regs_ret_val;
74 /* Routine to mark from registers that are preserved by the C compiler. */
75 /* This must be ported to every new architecture. It is noe optional, */
76 /* and should not be used on platforms that are either UNIX-like, or */
77 /* require thread support. */
81 #if defined(USE_ASM_PUSH_REGS)
82 # define HAVE_PUSH_REGS
83 #else /* No asm implementation */
86 # if defined(M68K) && defined(AMIGA)
87 /* AMIGA - could be replaced by generic code */
88 /* a0, a1, d0 and d1 are caller save */
91 asm("subq.w &0x4,%sp"); /* allocate word on top of stack */
93 asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
94 asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
95 asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
96 asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
97 asm("mov.l %a6,(%sp)"); asm("jsr _GC_push_one");
98 /* Skip frame pointer and stack pointer */
99 asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
100 asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
101 asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
102 asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
103 asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
104 asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
106 asm("addq.w &0x4,%sp"); /* put stack back where it was */
107 # define HAVE_PUSH_REGS
108 # else /* !__GNUC__ */
109 GC_push_one(getreg(REG_A2));
110 GC_push_one(getreg(REG_A3));
112 /* Can probably be changed to #if 0 -Kjetil M. (a4=globals)*/
113 GC_push_one(getreg(REG_A4));
115 GC_push_one(getreg(REG_A5));
116 GC_push_one(getreg(REG_A6));
117 /* Skip stack pointer */
118 GC_push_one(getreg(REG_D2));
119 GC_push_one(getreg(REG_D3));
120 GC_push_one(getreg(REG_D4));
121 GC_push_one(getreg(REG_D5));
122 GC_push_one(getreg(REG_D6));
123 GC_push_one(getreg(REG_D7));
124 # define HAVE_PUSH_REGS
125 # endif /* !__GNUC__ */
128 # if defined(M68K) && defined(MACOS)
129 # if defined(THINK_C)
130 # define PushMacReg(reg) \
134 sub.w #4,sp ; reserve space for one parameter.
138 ; skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
145 add.w #4,sp ; fix stack.
147 # define HAVE_PUSH_REGS
149 # endif /* THINK_C */
150 # if defined(__MWERKS__)
152 # define HAVE_PUSH_REGS
153 # endif /* __MWERKS__ */
156 #endif /* !USE_ASM_PUSH_REGS */
158 #if defined(HAVE_PUSH_REGS) && defined(THREADS)
159 # error GC_push_regs cannot be used with threads
160 /* Would fail for GC_do_blocking. There are probably other safety */
162 # undef HAVE_PUSH_REGS
165 #if !defined(HAVE_PUSH_REGS) && defined(UNIX_LIKE)
166 # include <ucontext.h>
169 /* Ensure that either registers are pushed, or callee-save registers */
170 /* are somewhere on the stack, and then call fn(arg, ctxt). */
171 /* ctxt is either a pointer to a ucontext_t we generated, or NULL. */
172 void GC_with_callee_saves_pushed(void (*fn)(ptr_t, void *),
178 # if defined(HAVE_PUSH_REGS)
180 # elif defined(UNIX_LIKE) && !defined(DARWIN) && !defined(ARM32) && \
181 !defined(MIPS) && !defined(HURD)
182 /* Older versions of Darwin seem to lack getcontext(). */
183 /* ARM Linux often doesn't support a real getcontext(). */
185 if (getcontext(&ctxt) < 0)
186 ABORT ("Getcontext failed: Use another register retrieval method?");
188 # if defined(SPARC) || defined(IA64)
189 /* On a register window machine, we need to save register */
190 /* contents on the stack for this to work. This may already be */
191 /* subsumed by the getcontext() call. */
193 GC_save_regs_ret_val = GC_save_regs_in_stack();
195 # endif /* register windows. */
196 # elif defined(HAVE_BUILTIN_UNWIND_INIT)
197 /* This was suggested by Richard Henderson as the way to */
198 /* force callee-save registers and register windows onto */
200 __builtin_unwind_init();
201 # else /* !HAVE_BUILTIN_UNWIND_INIT && !UNIX_LIKE */
202 /* && !HAVE_PUSH_REGS */
204 /* The idea is due to Parag Patel at HP. */
205 /* We're not sure whether he would like */
206 /* to be he acknowledged for it or not. */
208 register word * i = (word *) regs;
209 register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
211 /* Setjmp doesn't always clear all of the buffer. */
212 /* That tends to preserve garbage. Clear it. */
213 for (; (char *)i < lim; i++) {
216 # if defined(MSWIN32) || defined(MSWINCE) \
217 || defined(UTS4) || defined(LINUX) || defined(EWS4800)
220 (void) _setjmp(regs);
221 /* We don't want to mess with signals. According to */
222 /* SUSV3, setjmp() may or may not save signal mask. */
223 /* _setjmp won't, but is less portable. */
225 # endif /* !HAVE_PUSH_REGS ... */
226 /* FIXME: context here is sometimes just zero. At the moment the callees */
227 /* don't really need it. */
229 /* Strongly discourage the compiler from treating the above */
230 /* as a tail-call, since that would pop the register */
231 /* contents before we get a chance to look at them. */
232 GC_noop1((word)(&dummy));
235 void GC_push_regs_and_stack(ptr_t cold_gc_frame)
237 GC_with_callee_saves_pushed(GC_push_current_stack, cold_gc_frame);
240 #if defined(ASM_CLEAR_CODE)
243 ptr_t GC_clear_stack_inner(arg, limit)
244 ptr_t arg; word limit;
246 /* The real version is in a .S file */
248 #endif /* ASM_CLEAR_CODE */