_PROGRAMMING THE PENTIUM PROCESSOR_
by Ramesh Subramaniam and Kiran Kundargi

Example 1: (a) Instruction I2 is dependent on I1, so it can't be 
executed until I1 is complete; (b) the same instruction stream can  
be resheduled by a Pentium-aware compiler, resulting in parallel 
execution.

(a)

mov  eax,  source   /I1: move source contents to eax
add  eax,  ebx      /I2: add contents of eax to ebx
instr1...           /I3: some other instruction-
instr2...           /I4: -not dependent on eax, ebx or source
instr3...           /I5:  "

(b)

mov   eax, source   ||  instr1...
instr2...           ||  instr3...         
add  eax, ebx