Comparison Instructions

Testing if two floating point numbers are exactly equal is sometimes NOT a good idea. Floating point calculations are not exact. Sometimes values are not equal even though mathematically they should be. It is best to use "less than" or "less than or equal" instead of testing for exact equality. Here are some MIPS comparison instructions for single precision floating point:

Instruction	Operation
c.eq.s fs, ft	set condition bit if $fs == $ft
c.lt.s fs, ft	set condition bit if $fs < $ft
c.le.s fs, ft	set condition bit if $fs <= $ft

These instructions change the value in the condition bit, a part of the processor. The condition bit is set (made equal to one) if the condition is true. Otherwise the condition bit is cleared (made equal to zero). There are more comparison operations than these. But these notes use just these three. The others involve the various IEEE 754 codes for exceptional results.