analogous to commit
ddc7c4f936c7a90781072f10dbaa122007e939d0 for
mips64 and n32, remove the hack to load the syscall number into $2 via
asm, and use a constraint to let the compiler load it instead.
now, only $4, $5, and $6 are potential input-only registers. $2 is
always input and output, and $7 is both when it's an argument,
otherwise output-only. previously, $7 was treated as an input (with a
"1" constraint matching its output position) even when it was not an
input, which was arguably undefined behavior (asm input from
indeterminate value). this is corrected.
as before, $8, $9, and $10 are conditionally input-output registers
for 5-, 6-, and 7-argument syscalls. their role in input is carrying
in the values that will be stored on the stack for arguments 5-7.
their role in output is carrying back whatever the kernel has
clobbered them with, so that the compiler cannot assume they still
contain the input values.
static inline long __syscall0(long n)
{
register long r7 __asm__("$7");
static inline long __syscall0(long n)
{
register long r7 __asm__("$7");
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
- "addu $2,$0,%2 ; syscall"
- : "=&r"(r2), "=r"(r7) : "ir"(n), "0"(r2), "1"(r7)
+ "syscall"
+ : "+r"(r2), "=r"(r7)
+ :
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
{
register long r4 __asm__("$4") = a;
register long r7 __asm__("$7");
{
register long r4 __asm__("$4") = a;
register long r7 __asm__("$7");
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
- "addu $2,$0,%2 ; syscall"
- : "=&r"(r2), "=r"(r7) : "ir"(n), "0"(r2), "1"(r7),
- "r"(r4)
+ "syscall"
+ : "+r"(r2), "=r"(r7)
+ : "r"(r4)
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
register long r4 __asm__("$4") = a;
register long r5 __asm__("$5") = b;
register long r7 __asm__("$7");
register long r4 __asm__("$4") = a;
register long r5 __asm__("$5") = b;
register long r7 __asm__("$7");
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
- "addu $2,$0,%2 ; syscall"
- : "=&r"(r2), "=r"(r7) : "ir"(n), "0"(r2), "1"(r7),
- "r"(r4), "r"(r5)
+ "syscall"
+ : "+r"(r2), "=r"(r7)
+ : "r"(r4), "r"(r5)
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
register long r5 __asm__("$5") = b;
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7");
register long r5 __asm__("$5") = b;
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7");
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
- "addu $2,$0,%2 ; syscall"
- : "=&r"(r2), "=r"(r7) : "ir"(n), "0"(r2), "1"(r7),
- "r"(r4), "r"(r5), "r"(r6)
+ "syscall"
+ : "+r"(r2), "=r"(r7)
+ : "r"(r4), "r"(r5), "r"(r6)
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
register long r5 __asm__("$5") = b;
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7") = d;
register long r5 __asm__("$5") = b;
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7") = d;
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
- "addu $2,$0,%2 ; syscall"
- : "=&r"(r2), "=r"(r7) : "ir"(n), "0"(r2), "1"(r7),
- "r"(r4), "r"(r5), "r"(r6)
+ "syscall"
+ : "+r"(r2), "+r"(r7)
+ : "r"(r4), "r"(r5), "r"(r6)
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$8", "$9", "$10");
return r7 ? -r2 : r2;
}
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7") = d;
register long r8 __asm__("$8") = e;
register long r6 __asm__("$6") = c;
register long r7 __asm__("$7") = d;
register long r8 __asm__("$8") = e;
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
__asm__ __volatile__ (
"subu $sp,$sp,32 ; sw $8,16($sp) ; "
__asm__ __volatile__ (
"subu $sp,$sp,32 ; sw $8,16($sp) ; "
- "addu $2,$0,%3 ; syscall ;"
- : "=&r"(r2), "=r"(r7), "+r"(r8)
- : "ir"(n), "0"(r2), "1"(r7), "r"(r4), "r"(r5), "r"(r6)
+ : "+r"(r2), "+r"(r7), "+r"(r8)
+ : "r"(r4), "r"(r5), "r"(r6)
: SYSCALL_CLOBBERLIST, "$9", "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$9", "$10");
return r7 ? -r2 : r2;
}
register long r7 __asm__("$7") = d;
register long r8 __asm__("$8") = e;
register long r9 __asm__("$9") = f;
register long r7 __asm__("$7") = d;
register long r8 __asm__("$8") = e;
register long r9 __asm__("$9") = f;
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
__asm__ __volatile__ (
"subu $sp,$sp,32 ; sw $8,16($sp) ; sw $9,20($sp) ; "
__asm__ __volatile__ (
"subu $sp,$sp,32 ; sw $8,16($sp) ; sw $9,20($sp) ; "
- "addu $2,$0,%4 ; syscall ;"
- : "=&r"(r2), "=r"(r7), "+r"(r8), "+r"(r9)
- : "ir"(n), "0"(r2), "1"(r7), "r"(r4), "r"(r5), "r"(r6)
+ : "+r"(r2), "+r"(r7), "+r"(r8), "+r"(r9)
+ : "r"(r4), "r"(r5), "r"(r6)
: SYSCALL_CLOBBERLIST, "$10");
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST, "$10");
return r7 ? -r2 : r2;
}
register long r8 __asm__("$8") = e;
register long r9 __asm__("$9") = f;
register long r10 __asm__("$10") = g;
register long r8 __asm__("$8") = e;
register long r9 __asm__("$9") = f;
register long r10 __asm__("$10") = g;
- register long r2 __asm__("$2");
+ register long r2 __asm__("$2") = n;
__asm__ __volatile__ (
"subu $sp,$sp,32 ; sw $8,16($sp) ; sw $9,20($sp) ; sw $10,24($sp) ; "
__asm__ __volatile__ (
"subu $sp,$sp,32 ; sw $8,16($sp) ; sw $9,20($sp) ; sw $10,24($sp) ; "
- "addu $2,$0,%5 ; syscall ;"
- : "=&r"(r2), "=r"(r7), "+r"(r8), "+r"(r9), "+r"(r10)
- : "ir"(n), "0"(r2), "1"(r7), "r"(r4), "r"(r5), "r"(r6)
+ : "+r"(r2), "+r"(r7), "+r"(r8), "+r"(r9), "+r"(r10)
+ : "r"(r4), "r"(r5), "r"(r6)
: SYSCALL_CLOBBERLIST);
return r7 ? -r2 : r2;
}
: SYSCALL_CLOBBERLIST);
return r7 ? -r2 : r2;
}