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44acff5d04
* sysdeps/unix/sysv/linux/arm/sysdep.h (PSEUDO_RET_NOERRNO): Use unconditional mov. Remove nop.
223 lines
6.9 KiB
C
223 lines
6.9 KiB
C
/* Copyright (C) 1992, 93, 1995-2000, 2002, 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
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ARM changes by Philip Blundell, <pjb27@cam.ac.uk>, May 1997.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef _LINUX_ARM_SYSDEP_H
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#define _LINUX_ARM_SYSDEP_H 1
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/* There is some commonality. */
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#include <sysdeps/unix/arm/sysdep.h>
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/* For Linux we can use the system call table in the header file
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/usr/include/asm/unistd.h
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of the kernel. But these symbols do not follow the SYS_* syntax
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so we have to redefine the `SYS_ify' macro here. */
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#undef SYS_ify
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#define SWI_BASE (0x900000)
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#define SYS_ify(syscall_name) (__NR_##syscall_name)
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#ifdef __ASSEMBLER__
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/* Linux uses a negative return value to indicate syscall errors,
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unlike most Unices, which use the condition codes' carry flag.
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Since version 2.1 the return value of a system call might be
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negative even if the call succeeded. E.g., the `lseek' system call
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might return a large offset. Therefore we must not anymore test
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for < 0, but test for a real error by making sure the value in R0
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is a real error number. Linus said he will make sure the no syscall
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returns a value in -1 .. -4095 as a valid result so we can savely
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test with -4095. */
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#undef PSEUDO
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#define PSEUDO(name, syscall_name, args) \
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.text; \
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ENTRY (name); \
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DO_CALL (syscall_name, args); \
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cmn r0, $4096;
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#define PSEUDO_RET \
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RETINSTR(movcc, pc, lr); \
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b PLTJMP(SYSCALL_ERROR)
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#undef ret
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#define ret PSEUDO_RET
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#undef PSEUDO_END
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#define PSEUDO_END(name) \
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SYSCALL_ERROR_HANDLER \
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END (name)
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#undef PSEUDO_NOERRNO
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#define PSEUDO_NOERRNO(name, syscall_name, args) \
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.text; \
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ENTRY (name); \
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DO_CALL (syscall_name, args);
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#define PSEUDO_RET_NOERRNO \
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RETINSTR(mov, pc, lr);
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#undef ret_NOERRNO
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#define ret_NOERRNO PSEUDO_RET_NOERRNO
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#undef PSEUDO_END_NOERRNO
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#define PSEUDO_END_NOERRNO(name) \
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END (name)
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#if NOT_IN_libc
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# define SYSCALL_ERROR __local_syscall_error
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# define SYSCALL_ERROR_HANDLER \
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__local_syscall_error: \
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str lr, [sp, #-4]!; \
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str r0, [sp, #-4]!; \
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bl PLTJMP(C_SYMBOL_NAME(__errno_location)); \
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ldr r1, [sp], #4; \
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rsb r1, r1, #0; \
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str r1, [r0]; \
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mvn r0, #0; \
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ldr pc, [sp], #4;
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#else
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# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
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# define SYSCALL_ERROR __syscall_error
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#endif
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/* Linux takes system call args in registers:
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syscall number in the SWI instruction
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arg 1 r0
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arg 2 r1
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arg 3 r2
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arg 4 r3
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arg 5 r4 (this is different from the APCS convention)
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arg 6 r5
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arg 7 r6
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The compiler is going to form a call by coming here, through PSEUDO, with
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arguments
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syscall number in the DO_CALL macro
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arg 1 r0
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arg 2 r1
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arg 3 r2
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arg 4 r3
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arg 5 [sp]
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arg 6 [sp+4]
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arg 7 [sp+8]
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We need to shuffle values between R4..R6 and the stack so that the
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caller's v1..v3 and stack frame are not corrupted, and the kernel
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sees the right arguments.
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*/
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#undef DO_CALL
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#define DO_CALL(syscall_name, args) \
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DOARGS_##args \
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swi SYS_ify (syscall_name); \
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UNDOARGS_##args
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#define DOARGS_0 /* nothing */
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#define DOARGS_1 /* nothing */
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#define DOARGS_2 /* nothing */
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#define DOARGS_3 /* nothing */
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#define DOARGS_4 /* nothing */
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#define DOARGS_5 str r4, [sp, $-4]!; ldr r4, [sp, $4];
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#define DOARGS_6 mov ip, sp; stmfd sp!, {r4, r5}; ldmia ip, {r4, r5};
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#define DOARGS_7 mov ip, sp; stmfd sp!, {r4, r5, r6}; ldmia ip, {r4, r5, r6};
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#define UNDOARGS_0 /* nothing */
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#define UNDOARGS_1 /* nothing */
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#define UNDOARGS_2 /* nothing */
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#define UNDOARGS_3 /* nothing */
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#define UNDOARGS_4 /* nothing */
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#define UNDOARGS_5 ldr r4, [sp], $4;
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#define UNDOARGS_6 ldmfd sp!, {r4, r5};
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#define UNDOARGS_7 ldmfd sp!, {r4, r5, r6};
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#else /* not __ASSEMBLER__ */
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/* Define a macro which expands into the inline wrapper code for a system
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call. */
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#undef INLINE_SYSCALL
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#define INLINE_SYSCALL(name, nr, args...) \
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({ unsigned int _sys_result = INTERNAL_SYSCALL (name, , nr, args); \
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if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_result, ), 0)) \
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{ \
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__set_errno (INTERNAL_SYSCALL_ERRNO (_sys_result, )); \
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_sys_result = (unsigned int) -1; \
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} \
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(int) _sys_result; })
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#undef INTERNAL_SYSCALL_DECL
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#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
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#undef INTERNAL_SYSCALL
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#define INTERNAL_SYSCALL(name, err, nr, args...) \
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({ unsigned int _sys_result; \
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{ \
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register int _a1 asm ("a1"); \
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LOAD_ARGS_##nr (args) \
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asm volatile ("swi %1 @ syscall " #name \
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: "=r" (_a1) \
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: "i" (SYS_ify(name)) ASM_ARGS_##nr \
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: "memory"); \
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_sys_result = _a1; \
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} \
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(int) _sys_result; })
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#undef INTERNAL_SYSCALL_ERROR_P
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#define INTERNAL_SYSCALL_ERROR_P(val, err) \
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((unsigned int) (val) >= 0xfffff001u)
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#undef INTERNAL_SYSCALL_ERRNO
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#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
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#define LOAD_ARGS_0()
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#define ASM_ARGS_0
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#define LOAD_ARGS_1(a1) \
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_a1 = (int) (a1); \
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LOAD_ARGS_0 ()
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#define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1)
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#define LOAD_ARGS_2(a1, a2) \
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register int _a2 asm ("a2") = (int) (a2); \
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LOAD_ARGS_1 (a1)
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#define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2)
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#define LOAD_ARGS_3(a1, a2, a3) \
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register int _a3 asm ("a3") = (int) (a3); \
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LOAD_ARGS_2 (a1, a2)
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#define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3)
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#define LOAD_ARGS_4(a1, a2, a3, a4) \
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register int _a4 asm ("a4") = (int) (a4); \
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LOAD_ARGS_3 (a1, a2, a3)
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#define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4)
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#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
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register int _v1 asm ("v1") = (int) (a5); \
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LOAD_ARGS_4 (a1, a2, a3, a4)
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#define ASM_ARGS_5 ASM_ARGS_4, "r" (_v1)
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#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
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register int _v2 asm ("v2") = (int) (a6); \
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LOAD_ARGS_5 (a1, a2, a3, a4, a5)
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#define ASM_ARGS_6 ASM_ARGS_5, "r" (_v2)
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#define LOAD_ARGS_7(a1, a2, a3, a4, a5, a6, a7) \
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register int _v3 asm ("v3") = (int) (a7); \
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LOAD_ARGS_6 (a1, a2, a3, a4, a5, a6)
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#define ASM_ARGS_7 ASM_ARGS_6, "r" (_v3)
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#endif /* __ASSEMBLER__ */
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#endif /* linux/arm/sysdep.h */
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