debug examples

The regs debug command will display the following:

   Register Contents for p1, program debugtest
   %eax    0x00000035      %ecx    0x08048964      %edx    0x08049ae0
   %ebx    0x08047dac      %esp    0x08047d88      %ebp    0x08047d8c
   %esi    0x080499a4      %edi    0x08047db4      %eip    0x080487a7
   %eflags 0x00000246      %cs     0x00000017      %ss     0x0000001f
   %ds     0x0000001f      %es     0x0000001f      %fs     0x00000000
   %gs     0x00000000      %fpsw   0xffff0000      %fpcw   0xffff137f
   %fpip   0x00000000      %fpdp   0x08047b50
   %st0/%mm0 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %st1/%mm1 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %st2/%mm2 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %st3/%mm3 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %st4/%mm4 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %st5/%mm5 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %st6/%mm6 [ EMPTY ] 0xffff 8000 0000 0000 0000 ==       -infinity
   %st7/%mm7 [ EMPTY ] 0x0000 0000 0000 0000 0000 ==       0
   %mxcsr  0x00000000
   %xmm0 0.000000 0.000000 0.000000 0.000000
   %xmm1 0.000000 0.000000 0.000000 0.000000
   %xmm2 0.000000 0.000000 0.000000 0.000000
   %xmm3 0.000000 0.000000 0.000000 0.000000
   %xmm4 0.000000 0.000000 0.000000 0.000000
   %xmm5 0.000000 0.000000 0.000000 0.000000
   %xmm6 0.000000 0.000000 0.000000 0.000000
   %xmm7 0.000000 0.000000 0.000000 0.000000

To change and print the value of the second 32-bit float component in %xmm3 (note that the extended floating point registers must be enabled to do this):

   debug> print %xmm3b
   1.22445e-41
   debug> set %xmm3b=11.77
   debug> print %xmm3b
   11.77