ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Instruction Details
A8.6.174 SMMLA
Signed Most Significant Word Multiply Accumulate multiplies two signed 32-bit values, extracts the most
significant 32 bits of the result, and adds an accumulate value.
Optionally, you can specify that the result is rounded instead of being truncated. In this case, the constant
0x80000000 is added to the product before the high word is extracted.
Encoding T1 ARMv6T2, ARMv7
SMMLA{R} ,,,
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 1 1 1 0 1 1 0 1 0 1 Rn Ra Rd 0 0 0 R Rm
if Ra == ‘1111’ then SEE SMMUL;
d = UInt(Rd); n = UInt(Rn); m = UInt(Rm); a = UInt(Ra); round = (R == ‘1’);
if BadReg(d) || BadReg(n) || BadReg(m) || a == 13 then UNPREDICTABLE;
Encoding A1 ARMv6*, ARMv7
SMMLA{R} ,,,
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
cond 0 1 1 1 0 1 0 1 Rd Ra Rm 0 0 R 1 Rn
if Ra == ‘1111’ then SEE SMMUL;
d = UInt(Rd); n = UInt(Rn); m = UInt(Rm); a = UInt(Ra); round = (R == ‘1’);
if d == 15 || n == 15 || m == 15 then UNPREDICTABLE;
A8-346 Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. ARM DDI 0406B