GNU Scientific Library – Reference Manual: Examining floating point registers

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### A.2 Examining floating point registers

The contents of floating point registers can be examined using the command `info float` (on supported platforms).

    (gdb) info float
         st0: 0xc4018b895aa17a945000  Valid Normal -7.838871e+308
         st1: 0x3ff9ea3f50e4d7275000  Valid Normal 0.0285946
         st2: 0x3fe790c64ce27dad4800  Valid Normal 6.7415931e-08
         st3: 0x3ffaa3ef0df6607d7800  Spec  Normal 0.0400229
         st4: 0x3c028000000000000000  Valid Normal 4.4501477e-308
         st5: 0x3ffef5412c22219d9000  Zero  Normal 0.9580257
         st6: 0x3fff8000000000000000  Valid Normal 1
         st7: 0xc4028b65a1f6d243c800  Valid Normal -1.566206e+309
       fctrl: 0x0272 53 bit; NEAR; mask DENOR UNDER LOS;
       fstat: 0xb9ba flags 0001; top 7; excep DENOR OVERF UNDER LOS
        ftag: 0x3fff
         fip: 0x08048b5c
         fcs: 0x051a0023
      fopoff: 0x08086820
      fopsel: 0x002b

Individual registers can be examined using the variables $reg, where reg is the register name.

    (gdb) p $st1
    $1 = 0.02859464454261210347719