Opcode PACKSSDW
CPU: all which supported IA MMX:
Pentium (P55C only), Pentium (tm) Pro (P6) future models
Type of Instruction: User
Instruction: PACKSSDW dest,src
Description:
dest[15..0] <- SaturateSignedDWordToSignedWord dest[31..0]
dest[31..16] <- SaturateSignedDWordToSignedWord dest[63..32]
dest[47..32] <- SaturateSignedDWordToSignedWord src[31..0]
dest[63..46] <- SaturateSignedDWordToSignedWord src[63..32]
Note: This instruction packs and saturates signed data from src and dest to
dest.
If signed value of word larger or smaller that the range of signed byte
value is saturated (in case of overflow to 7Fh, in underflow to 80h).
Flags affected: None
Exceptions:
RM PM VM SMM Description
#GP(0) If Illegal memory operand's EA in CS,DS,ES,FS,GS
#SS(0) If illegal memory operand's EA in SS
#PF(fcode) If page fault
#AC #AC If unaligned memory reference then alignment
check enabled and in ring 3.
#UD #UD #UD #UD If CR0.EM = 1
#NM #NM #NM #NM If CR0.TS = 1
#MF #MF #MF #MF If pending FPU Exception
++++++++++++++++++++++++++++++++++++++
COP & Times:
PACKSSDW mm,mm/m64 0FH 6BH PostByte
P55C: n/a
future P6: n/a
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