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/Modules/_ctypes/libffi/src/cris/sysv.S

http://unladen-swallow.googlecode.com/
Assembly | 215 lines | 138 code | 42 blank | 35 comment | 2 complexity | b17e59bf6ba716c77cd9ca7a4e39e672 MD5 | raw file
  1/* -----------------------------------------------------------------------
  2   sysv.S - Copyright (c) 2004 Simon Posnjak
  3	    Copyright (c) 2005 Axis Communications AB
  4
  5   CRIS Foreign Function Interface
  6
  7   Permission is hereby granted, free of charge, to any person obtaining
  8   a copy of this software and associated documentation files (the
  9   ``Software''), to deal in the Software without restriction, including
 10   without limitation the rights to use, copy, modify, merge, publish,
 11   distribute, sublicense, and/or sell copies of the Software, and to
 12   permit persons to whom the Software is furnished to do so, subject to
 13   the following conditions:
 14
 15   The above copyright notice and this permission notice shall be included
 16   in all copies or substantial portions of the Software.
 17
 18   THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
 19   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 20   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 21   IN NO EVENT SHALL SIMON POSNJAK BE LIABLE FOR ANY CLAIM, DAMAGES OR
 22   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 23   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 24   OTHER DEALINGS IN THE SOFTWARE.
 25   ----------------------------------------------------------------------- */
 26
 27#define LIBFFI_ASM
 28#include <ffi.h>
 29#define CONCAT(x,y) x ## y
 30#define XCONCAT(x,y) CONCAT (x, y)
 31#define L(x) XCONCAT (__USER_LABEL_PREFIX__, x)
 32
 33	.text
 34
 35	;; OK, when we get called we should have this (according to
 36	;; AXIS ETRAX 100LX Programmer's Manual chapter 6.3).
 37	;;
 38	;; R10:	 ffi_prep_args (func. pointer)
 39	;; R11:  &ecif
 40	;; R12:  cif->bytes
 41	;; R13:  fig->flags
 42	;; sp+0: ecif.rvalue
 43	;; sp+4: fn (function pointer to the function that we need to call)
 44
 45	.globl  L(ffi_call_SYSV)
 46	.type   L(ffi_call_SYSV),@function
 47	.hidden	L(ffi_call_SYSV)
 48
 49L(ffi_call_SYSV):
 50	;; Save the regs to the stack.
 51	push $srp
 52	;; Used for stack pointer saving.
 53	push $r6
 54	;; Used for function address pointer.
 55	push $r7
 56	;; Used for stack pointer saving.
 57	push $r8
 58	;; We save fig->flags to stack we will need them after we
 59	;; call The Function.
 60	push $r13
 61
 62	;; Saving current stack pointer.
 63	move.d $sp,$r8
 64	move.d $sp,$r6
 65
 66	;; Move address of ffi_prep_args to r13.
 67	move.d $r10,$r13
 68
 69	;; Make room on the stack for the args of fn.
 70	sub.d  $r12,$sp
 71
 72	;; Function void ffi_prep_args(char *stack, extended_cif *ecif) parameters are:
 73	;; 	r10 <-- stack pointer
 74	;; 	r11 <-- &ecif (already there)
 75	move.d $sp,$r10
 76
 77	;; Call the function.
 78	jsr $r13
 79
 80	;; Save the size of the structures which are passed on stack.
 81	move.d $r10,$r7
 82
 83	;; Move first four args in to r10..r13.
 84	move.d [$sp+0],$r10
 85	move.d [$sp+4],$r11
 86	move.d [$sp+8],$r12
 87	move.d [$sp+12],$r13
 88
 89	;; Adjust the stack and check if any parameters are given on stack.
 90	addq 16,$sp
 91	sub.d $r7,$r6
 92	cmp.d $sp,$r6
 93
 94	bpl go_on
 95	nop
 96
 97go_on_no_params_on_stack:
 98	move.d $r6,$sp
 99
100go_on:
101	;; Discover if we need to put rval address in to r9.
102	move.d [$r8+0],$r7
103	cmpq FFI_TYPE_STRUCT,$r7
104	bne call_now
105	nop
106
107	;; Move rval address to $r9.
108	move.d [$r8+20],$r9
109
110call_now:
111	;; Move address of The Function in to r7.
112	move.d [$r8+24],$r7
113
114	;; Call The Function.
115	jsr $r7
116
117	;; Reset stack.
118	move.d $r8,$sp
119
120	;; Load rval type (fig->flags) in to r13.
121	pop $r13
122
123	;; Detect rval type.
124	cmpq FFI_TYPE_VOID,$r13
125	beq epilogue
126
127	cmpq FFI_TYPE_STRUCT,$r13
128	beq epilogue
129
130	cmpq FFI_TYPE_DOUBLE,$r13
131	beq return_double_or_longlong
132
133	cmpq FFI_TYPE_UINT64,$r13
134	beq return_double_or_longlong
135
136	cmpq FFI_TYPE_SINT64,$r13
137	beq return_double_or_longlong
138	nop
139
140	;; Just return the 32 bit value.
141	ba return
142	nop
143
144return_double_or_longlong:
145	;; Load half of the rval to r10 and the other half to r11.
146	move.d [$sp+16],$r13
147	move.d $r10,[$r13]
148	addq 4,$r13
149	move.d $r11,[$r13]
150	ba epilogue
151	nop
152
153return:
154	;; Load the rval to r10.
155	move.d [$sp+16],$r13
156	move.d $r10,[$r13]
157
158epilogue:
159	pop $r8
160	pop $r7
161	pop $r6
162	Jump [$sp+]
163
164	.size   ffi_call_SYSV,.-ffi_call_SYSV
165
166/* Save R10..R13 into an array, somewhat like varargs.  Copy the next
167   argument too, to simplify handling of any straddling parameter.
168   Save R9 and SP after those.  Jump to function handling the rest.
169   Since this is a template, copied and the main function filled in by
170   the user.  */
171
172	.globl	L(ffi_cris_trampoline_template)
173	.type	L(ffi_cris_trampoline_template),@function
174	.hidden	L(ffi_cris_trampoline_template)
175
176L(ffi_cris_trampoline_template):
1770:
178	/* The value we get for "PC" is right after the prefix instruction,
179	   two bytes from the beginning, i.e. 0b+2. */
180	move.d $r10,[$pc+2f-(0b+2)]
181	move.d $pc,$r10
1821:
183	addq 2f-1b+4,$r10
184	move.d $r11,[$r10+]
185	move.d $r12,[$r10+]
186	move.d $r13,[$r10+]
187	move.d [$sp],$r11
188	move.d $r11,[$r10+]
189	move.d $r9,[$r10+]
190	move.d $sp,[$r10+]
191	subq FFI_CRIS_TRAMPOLINE_DATA_PART_SIZE,$r10
192	move.d 0,$r11
1933:
194        jump 0
1952:
196	.size	ffi_cris_trampoline_template,.-0b
197
198/* This macro create a constant usable as "extern const int \name" in
199   C from within libffi, when \name has no prefix decoration.  */
200
201	.macro const name,value
202	.globl	\name
203	.type	\name,@object
204	.hidden	\name
205\name:
206	.dword  \value
207	.size	\name,4
208	.endm
209
210/* Constants for offsets within the trampoline.  We could do this with
211   just symbols, avoiding memory contents and memory accesses, but the
212   C usage code would look a bit stranger.  */
213
214	const L(ffi_cris_trampoline_fn_offset),2b-4-0b
215	const L(ffi_cris_trampoline_closure_offset),3b-4-0b