User`s guide

Chapter 7: Debugging Machine Language Code

For registers with alternate names, the dbx variable $regstyle controls which

name is displayed when you disassemble code (as described in “Examining

$r8... $r11 $t0... $t7

$a4... $a7,

$ta0... $ta3

Temporaries (32 bit)

Arguments (64 bit)

$r12... $r15 $t4... $t7,

$t0... $t3

$ta0... $ta3

Temporaries (32 bit)

Temporaries (64 bit)

$r16... $r23 $s0... $s7 Saved across procedure calls

$r24... $r25 $t8... $t9 Temporaries

$r26... $r27 $k0... $k1 Reserved for kernel

$r28 $gp Global pointer

$r29 $sp Stack pointer

$r30 $s8 Saved across procedure calls

$r31 $ra Return address

$mmhi Most signiﬁcant multiply/divide result

$mmlo Least signiﬁcant multiply/divide result

$fcsr Floating point control and status register

$feir Floating point exception instruction register

$cause Exception cause register

$d0, $d2, ... $d30

$d0, $d2, ... $d31

Double precision ﬂoating point registers

(32 bit)

(64 bit)

$f0, $f2, ... $f30

$f0, $f1, ... $f31

Single precision ﬂoating point registers

(32 bit)

(64 bit)

Table 7-1 (continued) Hardware Registers and Aliases