BC1F - MIPS instruction reference

bc1fBranch if FP condition false 
Branches to label if the FP condition flag (flag 0 by default) is false, as set by a preceding compare instruction.
Used in Floating point and Coprocessor 1MIPS assembly
 
Forms  bc1f   
 bc1f ,   
Branches to 'label' if the FP condition flag specified by the immediate operand is false (0). Allows branching on the unset result of any of the 8 FP condition flags.
Operands label A named address in the program, such as the start of a loop or a variable in .data. 
cc A floating-point condition flag number, 0 to 7. Comparisons set these flags; bc1t and bc1f test them. 
Use after a FP compare instruction when you want to branch on the condition NOT being met. Note: mnemonic is BC1F, not BCLF.
 .data
less: .float 1.0
greater: .float 2.0
.text
# Compare 1.0 and 2.0, then the reverse. A taken branch skips the assignment of 1; inspect $t2/$t3 for markers 2 (taken) and 1 (fall-through).
l.s $f0, less
l.s $f2, greater
c.lt.s $f0, $f2
li $t2, 0
bc1f 0, first_taken
li $t2, 1
b first_done # Skip the other marker unconditionally.
first_taken: li $t2, 2
first_done:
c.lt.s $f2, $f0
li $t3, 0
bc1f 0, second_taken
li $t3, 1
b second_done # Skip the other marker unconditionally.
second_taken: li $t3, 2
second_done: