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Bgtzl, Branch on greater than zero likely – NEC Network Controller uPD98502 User Manual

Page 455

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APPENDIX A MIPS III INSTRUCTION SET DETAILS

Preliminary User’s Manual S15543EJ1V0UM

455

BGTZL

Branch On Greater Than Zero Likely

BGTZL

rs

BGTZL

0 1 0 1 1 1

0

0 0 0 0 0

offset

31

26 25

21 20

16 15

0

6

5

5

16

Format:

BGTZL 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. The contents of general register rs are compared to zero. If the

contents of general register

rs are greater than zero, then the program branches to the target address, with a delay

of one instruction. If the conditional branch is not taken, the instruction in the branch delay slot is nullified.

Operation:

32

T:

target

← (offset

15

)

14

|| offset || 0

2

condition

← (GPR [rs]

31

= 0) and (GPR [rs]

≠ 0

32

)

T+1: if condition then

PC

← PC + target

else

NullifyCurrentInstruction

endif

64

T:

target

← (offset

15

)

46

|| offset || 0

2

condition

← (GPR [rs]

63

= 0) and (GPR [rs]

≠ 0

64

)

T+1: if condition then

PC

← PC + target

else

NullifyCurrentInstruction

endif

Exceptions:

None