MMX(TM) Technology Intrinsics Implementation

Key to the table entries

A = Expected to give significant performance gain over non-intrinsic-based code equivalent.
B = Non-intrinsic-based source code would be better; the intrinsic's implementation may map directly to native instructions, but they offer no significant performance gain.
C = Requires contorted implementation for particular microarchitecture. Will result in very poor performance if used.

Intrinsic Name	MMX(TM) Technology Streaming SIMD Extensions Streaming SIMD Extensions 2	Itanium® Architecture
_mm_empty	A	B
_mm_cvtsi32_si64	A	A
_mm_cvtsi64_si32	A	A
_mm_packs_pi16	A	A
_mm_packs_pi32	A	A
_mm_packs_pu16	A	A
_mm_unpackhi_pi8	A	A
_mm_unpackhi_pi16	A	A
_mm_unpackhi_pi32	A	A
_mm_unpacklo_pi8	A	A
_mm_unpacklo_pi16	A	A
_mm_unpacklo_pi32	A	A
_mm_add_pi8	A	A
_mm_add_pi16	A	A
_mm_add_pi32	A	A
_mm_adds_pi8	A	A
_mm_adds_pi16	A	A
_mm_adds_pu8	A	A
_mm_adds_pu16	A	A
_mm_sub_pi8	A	A
_mm_sub_pi16	A	A
_mm_sub_pi32	A	A
_mm_subs_pi8	A	A
_mm_subs_pi16	A	A
_mm_subs_pu8	A	A
_mm_subs_pu16	A	A
_mm_madd_pi16	A	C
_mm_mulhi_pi16	A	A
_mm_mullo_pi16	A	A
_mm_sll_pi16	A	A
_mm_slli_pi16	A	A
_mm_sll_pi32	A	A
_mm_slli_pi32	A	A
_mm_sll_pi64	A	A
_mm_slli_pi64	A	A
_mm_sra_pi16	A	A
_mm_srai_pi16	A	A
_mm_sra_pi32	A	A
_mm_srai_pi32	A	A
_mm_srl_pi16	A	A
_mm_srli_pi16	A	A
_mm_srl_pi32	A	A
_mm_srli_pi32	A	A
_mm_srl_si64	A	A
_mm_srli_si64	A	A
_mm_and_si64	A	A
_mm_andnot_si64	A	A
_mm_or_si64	A	A
_mm_xor_si64	A	A
_mm_cmpeq_pi8	A	A
_mm_cmpeq_pi16	A	A
_mm_cmpeq_pi32	A	A
_mm_cmpgt_pi8	A	A
_mm_cmpgt_pi16	A	A
_mm_cmpgt_pi32	A	A
_mm_setzero_si64	A	A
_mm_set_pi32	A	A
_mm_set_pi16	A	C
_mm_set_pi8	A	C
_mm_set1_pi32	A	A
_mm_set1_pi16	A	A
_mm_set1_pi8	A	A
_mm_setr_pi32	A	A
_mm_setr_pi16	A	C
_mm_setr_pi8	A	C

_mm_empty is implemented in Itanium instructions as a NOP for source compatibility only.