APPENDIX A MIPS III INSTRUCTION SET DETAILS
460 Preliminary Users Manual S15543EJ1V0UM
BLTZALL Branch On Less Than Zero And Link Likely BLTZALL
rs

REGIMM

0 0 0 0 0 1

BLTZALL

1 0 0 1 0 offset

31 26 25 21 20 16 15 0
655 16
Format:
BLTZALL rs, offset
Description:
A branch target address is computed from the sum of the address of the instruction in the delay slot and the 16-bit
offset,
shifted left two bits and sign-extended. Unconditionally, the address of the instruction after the delay slot is
placed in the link register,
r31
. If the contents of general register
rs
are smaller than zero when compared to zero,
then the program branches to the target address, with a delay of one instruction.
General register
r31
should not be specified as general register
rs
. If register
r31
is specified, restarting may be
impossible due to the destruction of
rs
contents caused by storing a link address. Even such instructions are
executed, an exception does not result.
Operation:
32 T: target (offset15)14 || offset || 02
condition (GPR [rs]31 = 1)
GPR [31] PC + 8
T+1: if condition then
PC PC + target
else
NullifyCurrentInstruction
endif
64 T: target (offset15)46 || offset || 02
condition (GPR [rs]63 = 1)
GPR [31] PC + 8
T+1: if condition then
PC PC + target
else
NullifyCurrentInstruction
endif
Exceptions:
None