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

Assembler syntax
SMULW {,} ,
where:
Instruction Details
Specifies which half of the source register is used as the second multiply operand. If
is B, then the bottom half (bits [15:0]) of is used. If is T, then the top half
(bits [31:16]) of is used.
See Standard assembler syntax fields on page A8-7.
The destination register.
The first operand register.
The source register whose bottom or top half (selected by ) is the second multiply
operand.
Operation
if ConditionPassed() then
EncodingSpecificOperations();
operand2 = if m_high then R[m] else R[m];
product = SInt(R[n]) * SInt(operand2);
R[d] = product;
// Signed overflow cannot occur
Exceptions
None.
ARM DDI 0406B Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. A8-359