Register Usage

The assembler conventions on register usage

Name Reg. No. Usage Preserved On Call

$zero 0 Constant value 0 N.A.

1 Reserved for Assm N.A.

$v0-$v1 2-3 Result registers No

$a0-$a3 4-7 Arguments Yes

$t0-$t7 8-15 Temporaries No

$s0-$s7 16-23 Saved Locals Yes

$t8-$t9 24-25 More temporaries No

26-27 Operating System N.A.

$gp 28 Global Pointer Yes

$sp 29 Stack Pointer Yes

$fp 30 Frame Pointer Yes

$ra 31 Return Address Yes

See Appendix A-6 for more information

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