Itanium® Architecture for Programmers: Understanding 64-Bit Processors and EPIC Principles

5.7. Other Structured Programming Constructs

Here we introduce unc (the unconditional compare type completer) for the Itanium compare instructions and outline, at the assembly language level, a few additional structured programming constructs used by high-level languages.

5.7.1. Unconditional Compare Instructions

We shall briefly discuss the unconditional form of Itanium integer compare instructions with the compare type completer ctype=unc, whose behavior is best understood by contrasting it with the ordinary form of a compare instruction with no completer. The unconditional compare instructions have familiar features:

cmp.crel.unc p1,p2=r2,r3       // two registers
cmp.crel.unc p1,p2=imm8,r3     // immed and one register
cmp.crel.unc p1,p2=r0,r3 // ...