Full-Word Aligned

However if you want to perform floating point arithmetic, then the floating point number must be in a floating point register.

The previous program exchanged the bit patterns held at two memory locations. It could just as easily been written using general purpose registers since no arithmetic was done with the bit patterns in the registers:

## swap.asm
##
## Exchange the values in valA and valB

        .text
        .globl  main

main:
        lw      $t0,valA        # $t0  <-- valA
        lw      $t1,valB        # $t1  <-- valB
        sw      $t0,valB        # $t0  --> valB
        sw      $t1,valA        # $t1  --> valA

        li      $v0,10          # code 10 == exit
        syscall                 # Return to OS.
                
        .data
valA:   .float  8.32            # 32 bit floating point value
valB:   .float  -0.6234e4       # 32 bit floating point value
                                # small 'e' only

For both single precision load and store instructions (as with the general purpose load and store instructions) the memory address must be full-word aligned. It must be a multiple of four. Ordinarily this is not a problem. The assembler takes care of this.