8.1 Parallels Between Integer and Floating-Point Instructions

When one learns elementary mechanics in a physics course, certain parallels are often illustrated between the analysis of circular motion and the standard description of linear motion: angular momentum and linear momentum, moment of inertia and mass, etc. Drawing such parallels can assist the learning process both mnemonically through the similarities and conceptually through the contrasts.

Chapters 4 through 6 discussed Itanium integer instructions, several groupings of which have direct analogues in instructions for data in floating-point formats, as depicted in Table 8-1.

Other groupings of Itanium integer instructions with no floating-point counterparts include the shift, byte-manipulation, and data-independent branch instructions. Conversely, several groupings of floating-point instructions discussed in this chapter have no direct integer counterparts.

Table 8-1. Comparisons of Itanium Integer and Floating-Point Instructions

Type of Instruction	Integer	Floating-Point
Load/Store	ld1, ld2, ld4, ld8	ldfs, ldfd, ldfe, ldf8
	st1, st2, st4, st8	stfs, stfd, stfe, stf8
Arithmetic	add	fadd (pseudo-op)
	sub	fsub (pseudo-op)
	xmpy (pseudo-op)	fmpy (pseudo-op)
Logic	and	fand
	andcm	fandcm
	or	for
	xor	fxor
Compare	cmp	fcmp