Opcode PADDB
CPU: all which supported IA MMX:
Pentium (P55C only), Pentium (tm) Pro (P6) future models
Type of Instruction: User
Instruction: PADDB dest,src
Description:
dest[7..0] <- dest[7..0] + src[7..0]
dest[15..8] <- dest[15..8] + src[15..8]
dest[23..16] <- dest[23..16] + src[23..16]
dest[31..24] <- dest[31..24] + src[31..24]
dest[39..32] <- dest[39..32] + src[39..32]
dest[47..40] <- dest[47..40] + src[47..40]
dest[55..48] <- dest[55..48] + src[55..48]
dest[63..56] <- dest[63..56] + src[63..56]
Note: This instruction adds the bytes of the source to the bytes of the
destination and writes the results to the MMX register.
When the result is too large to be represented in a packed byte
(overflow), the result wraps around and the lower 8 bits are writen to
the destination register.
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
#13 #13 If any part of the the operand lies outside of
the EA space from 0 to FFFFH
++++++++++++++++++++++++++++++++++++++
COP & Times:
PADDB mm,mm/m64 0FH FCH PostByte
P55C: n/a
future P6: n/a
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