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musl/arch/mips/syscall_arch.h

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syscall organization overhaul now public syscall.h only exposes __NR_* and SYS_* constants and the variadic syscall function. no macros or inline functions, no __syscall_ret or other internal details, no 16-/32-bit legacy syscall renaming, etc. this logic has all been moved to src/internal/syscall.h with the arch-specific parts in arch/$(ARCH)/syscall_arch.h, and the amount of arch-specific stuff has been reduced to a minimum. changes still need to be reviewed/double-checked. minimal testing on i386 and mips has already been performed.
2012-09-09 02:43:14 +00:00
#define __SYSCALL_LL_E(x) \
((union { long long ll; long l[2]; }){ .ll = x }).l[0], \
((union { long long ll; long l[2]; }){ .ll = x }).l[1]
#define __SYSCALL_LL_O(x) 0, __SYSCALL_LL_E((x))
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
#ifndef __clang__
#define __asm_syscall(...) do { \
register long r2 __asm__("$2"); \
__asm__ __volatile__ ( \
improve mips syscall asm constraints to use immediates, if possible by using the "ir" constraint (immediate or register) and the carefully constructed instruction addu $2,$0,%2 which can take either an immediate or a register for %2, the new inline asm admits maximal optimization with no register spillage to the stack when the compiler successfully performs constant propagration, but still works by allocating a register when the syscall number cannot be recognized as a constant. in the case of syscalls with 0-3 arguments it barely matters, but for 4-argument syscalls, using an immediate for the syscall number avoids creating a stack frame for the syscall wrapper function.
2012-09-11 06:23:47 +00:00
"addu $2,$0,%2 ; syscall" \
fix buggy constraints in mips inline syscall asm if same register is used for input/output, the compiler must be told. otherwise is generates random junk code that clobbers the result. in pure syscall-wrapper functions, nothing went wrong, but in more complex functions where register allocation is non-trivial, things broke badly.
2012-09-15 06:22:10 +00:00
: "=&r"(r2), "=r"(r7) : "ir"(n), __VA_ARGS__, "0"(r2), "1"(r7) \
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \
eliminate assumption that mips syscall restart preserves r25 all past and current kernel versions have done so, but there seems to be no reason it's necessary and the sentiment from everyone I've asked has been that we should not rely on it. instead, use r7 (an argument register) which will necessarily be preserved upon syscall restart. however this only works for 0-3 argument syscalls, and we have to resort to the function call for 4-argument syscalls.
2012-09-11 02:43:22 +00:00
"$14", "$15", "$24", "$25", "hi", "lo", "memory"); \
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
return r7 ? -r2 : r2; \
} while (0)
static inline long __syscall0(long n)
{
improve mips syscall asm constraints to use immediates, if possible by using the "ir" constraint (immediate or register) and the carefully constructed instruction addu $2,$0,%2 which can take either an immediate or a register for %2, the new inline asm admits maximal optimization with no register spillage to the stack when the compiler successfully performs constant propagration, but still works by allocating a register when the syscall number cannot be recognized as a constant. in the case of syscalls with 0-3 arguments it barely matters, but for 4-argument syscalls, using an immediate for the syscall number avoids creating a stack frame for the syscall wrapper function.
2012-09-11 06:23:47 +00:00
register long r7 __asm__("$7");
__asm_syscall("i"(0));
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
}
static inline long __syscall1(long n, long a)
{
register long r4 __asm__("$4") = a;
improve mips syscall asm constraints to use immediates, if possible by using the "ir" constraint (immediate or register) and the carefully constructed instruction addu $2,$0,%2 which can take either an immediate or a register for %2, the new inline asm admits maximal optimization with no register spillage to the stack when the compiler successfully performs constant propagration, but still works by allocating a register when the syscall number cannot be recognized as a constant. in the case of syscalls with 0-3 arguments it barely matters, but for 4-argument syscalls, using an immediate for the syscall number avoids creating a stack frame for the syscall wrapper function.
2012-09-11 06:23:47 +00:00
register long r7 __asm__("$7");
__asm_syscall("r"(r4));
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
}
static inline long __syscall2(long n, long a, long b)
{
register long r4 __asm__("$4") = a;
register long r5 __asm__("$5") = b;
improve mips syscall asm constraints to use immediates, if possible by using the "ir" constraint (immediate or register) and the carefully constructed instruction addu $2,$0,%2 which can take either an immediate or a register for %2, the new inline asm admits maximal optimization with no register spillage to the stack when the compiler successfully performs constant propagration, but still works by allocating a register when the syscall number cannot be recognized as a constant. in the case of syscalls with 0-3 arguments it barely matters, but for 4-argument syscalls, using an immediate for the syscall number avoids creating a stack frame for the syscall wrapper function.
2012-09-11 06:23:47 +00:00
register long r7 __asm__("$7");
__asm_syscall("r"(r4), "r"(r5));
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
}
static inline long __syscall3(long n, long a, long b, long c)
{
register long r4 __asm__("$4") = a;
register long r5 __asm__("$5") = b;
register long r6 __asm__("$6") = c;
improve mips syscall asm constraints to use immediates, if possible by using the "ir" constraint (immediate or register) and the carefully constructed instruction addu $2,$0,%2 which can take either an immediate or a register for %2, the new inline asm admits maximal optimization with no register spillage to the stack when the compiler successfully performs constant propagration, but still works by allocating a register when the syscall number cannot be recognized as a constant. in the case of syscalls with 0-3 arguments it barely matters, but for 4-argument syscalls, using an immediate for the syscall number avoids creating a stack frame for the syscall wrapper function.
2012-09-11 06:23:47 +00:00
register long r7 __asm__("$7");
__asm_syscall("r"(r4), "r"(r5), "r"(r6));
}
static inline long __syscall4(long n, long a, long b, long c, long d)
{
register long r4 __asm__("$4") = a;
register long r5 __asm__("$5") = b;
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7") = d;
fix buggy constraints in mips inline syscall asm if same register is used for input/output, the compiler must be told. otherwise is generates random junk code that clobbers the result. in pure syscall-wrapper functions, nothing went wrong, but in more complex functions where register allocation is non-trivial, things broke badly.
2012-09-15 06:22:10 +00:00
__asm_syscall("r"(r4), "r"(r5), "r"(r6));
inline syscall support for mips this drastically reduces the size of some functions which are purely syscall wrappers. disabled for clang due to known bugs satisfying register constraints.
2012-09-09 05:01:19 +00:00
}
#else
syscall organization overhaul now public syscall.h only exposes __NR_* and SYS_* constants and the variadic syscall function. no macros or inline functions, no __syscall_ret or other internal details, no 16-/32-bit legacy syscall renaming, etc. this logic has all been moved to src/internal/syscall.h with the arch-specific parts in arch/$(ARCH)/syscall_arch.h, and the amount of arch-specific stuff has been reduced to a minimum. changes still need to be reviewed/double-checked. minimal testing on i386 and mips has already been performed.
2012-09-09 02:43:14 +00:00
static inline long __syscall0(long n)
{
return (__syscall)(n);
}
static inline long __syscall1(long n, long a)
{
return (__syscall)(n, a);
}
static inline long __syscall2(long n, long a, long b)
{
return (__syscall)(n, a, b);
}
static inline long __syscall3(long n, long a, long b, long c)
{
return (__syscall)(n, a, b, c);
}
static inline long __syscall4(long n, long a, long b, long c, long d)
{
return (__syscall)(n, a, b, c, d);
}
improve mips syscall asm constraints to use immediates, if possible by using the "ir" constraint (immediate or register) and the carefully constructed instruction addu $2,$0,%2 which can take either an immediate or a register for %2, the new inline asm admits maximal optimization with no register spillage to the stack when the compiler successfully performs constant propagration, but still works by allocating a register when the syscall number cannot be recognized as a constant. in the case of syscalls with 0-3 arguments it barely matters, but for 4-argument syscalls, using an immediate for the syscall number avoids creating a stack frame for the syscall wrapper function.
2012-09-11 06:23:47 +00:00
#endif
syscall organization overhaul now public syscall.h only exposes __NR_* and SYS_* constants and the variadic syscall function. no macros or inline functions, no __syscall_ret or other internal details, no 16-/32-bit legacy syscall renaming, etc. this logic has all been moved to src/internal/syscall.h with the arch-specific parts in arch/$(ARCH)/syscall_arch.h, and the amount of arch-specific stuff has been reduced to a minimum. changes still need to be reviewed/double-checked. minimal testing on i386 and mips has already been performed.
2012-09-09 02:43:14 +00:00
static inline long __syscall5(long n, long a, long b, long c, long d, long e)
{
return (__syscall)(n, a, b, c, d, e);
}
static inline long __syscall6(long n, long a, long b, long c, long d, long e, long f)
{
return (__syscall)(n, a, b, c, d, e, f);
}