libc-top-half/musl/src/thread/powerpc64/clone.s

   1 .text
   2 .global __clone
   3 .hidden __clone
   4 .type __clone, %function
   5 __clone:
   6         # int clone(fn, stack, flags, arg, ptid, tls, ctid)
   7         #            a  b       c     d     e    f    g
   8         #            3  4       5     6     7    8    9
   9         # pseudo C code:
  10         # tid = syscall(SYS_clone,c,b,e,f,g);
  11         # if (!tid) syscall(SYS_exit, a(d));
  12         # return tid;
  13
  14         # create initial stack frame for new thread
  15         clrrdi 4, 4, 4
  16         li     0, 0
  17         stdu   0,-32(4)
  18
  19         # save fn and arg to child stack
  20         std    3,  8(4)
  21         std    6, 16(4)
  22
  23         # shuffle args into correct registers and call SYS_clone
  24         mr    3, 5
  25         #mr   4, 4
  26         mr    5, 7
  27         mr    6, 8
  28         mr    7, 9
  29         li    0, 120  # SYS_clone = 120
  30         sc
  31
  32         # if error, negate return (errno)
  33         bns+  1f
  34         neg   3, 3
  35
  36 1:      # if we're the parent, return
  37         cmpwi cr7, 3, 0
  38         bnelr cr7
  39
  40         # we're the child. call fn(arg)
  41         ld     3, 16(1)
  42         ld    12,  8(1)
  43         mtctr 12
  44         bctrl
  45
  46         # call SYS_exit. exit code is already in r3 from fn return value
  47         li    0, 1    # SYS_exit = 1
  48         sc