|author||Rich Felker <email@example.com>||2012-09-11 02:23:47 -0400|
|committer||Rich Felker <firstname.lastname@example.org>||2012-09-11 02:23:47 -0400|
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.
Diffstat (limited to 'arch/mips/atomic.h')
0 files changed, 0 insertions, 0 deletions