Volume 4: IA-32 Intel
®
MMX™ Technology Instruction Reference
4:413
PADDSB/PADDSW—Packed Add with Saturation
Description
Adds the individual signed data elements (bytes or words) of the source operand
(second operand) to the individual signed data elements of the destination operand
(first operand). (See
.) If the result of an individual addition exceeds the
range for the specified data type, the result is saturated. The destination operand must
be an MMX technology register; the source operand can be either an MMX technology
register or a quadword memory location.
The PADDSB instruction adds the signed bytes of the source operand to the signed
bytes of the destination operand and stores the results to the destination operand.
When an individual result is beyond the range of a signed byte (that is, greater than
7FH or less than 80H), the saturated byte value of 7FH or 80H, respectively, is written
to the destination operand.
The PADDSW instruction adds the signed words of the source operand to the signed
words of the destination operand and stores the results to the destination operand.
When an individual result is beyond the range of a signed word (that is, greater than
7FFFH or less than 8000H), the saturated word value of 7FFFH or 8000H, respectively,
is written to the destination operand.
Operation
IF instruction is PADDSB
THEN
DEST(7..0)
SaturateToSignedByte(DEST(7..0) + SRC (7..0)) ;
DEST(15..8)
SaturateToSignedByte(DEST(15..8) + SRC(15..8) );
DEST(23..16)
SaturateToSignedByte(DEST(23..16)+ SRC(23..16) );
DEST(31..24)
SaturateToSignedByte(DEST(31..24) + SRC(31..24) );
DEST(39..32)
SaturateToSignedByte(DEST(39..32) + SRC(39..32) );
DEST(47..40)
SaturateToSignedByte(DEST(47..40)+ SRC(47..40) );
DEST(55..48)
SaturateToSignedByte(DEST(55..48) + SRC(55..48) );
DEST(63..56)
SaturateToSignedByte(DEST(63..56) + SRC(63..56) );
Opcode
Instruction
Description
0F EC /r
PADDSB
mm, mm/m64
Add signed packed bytes from
mm/m64
to signed packed
bytes in
mm
and saturate.
0F ED /r
PADDSW
mm, mm/m64
Add signed packed words from
mm/m64
to signed packed
words in
mm
and saturate.
Figure 3-6.
Operation of the PADDSW Instruction
3006016
PADDSW mm, mm/m64
mm
mm/m64
mm
1000000000000000
0111111100111000
+
+
+
+
1111111111111111
0001011100000111
1000000000000000
0111111111111111
Summary of Contents for ITANIUM ARCHITECTURE
Page 1: ......
Page 7: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 199: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 352: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 589: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 590: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 591: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 603: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...
Page 604: ......