IBM SA14-2339-04 Personal Computer User Manual


 
Instruction Set 9-95
macchw
Multiply Accumulate Cross Halfword to Word Modulo Signed
macchw
Multiply Accumulate Cross Halfword to Word Modulo Signed
prod
0:31
(RA)
16:31
x (RB)
0:15
signed
temp
0:32
prod
0:31
+ (RT)
(RT)
temp
1:32
The low-order halfword of RA is multiplied by the high-order halfword of RB. The signed product is
summed with the contents of RT and the sum is stored in a 33-bit temporary register. The contents of
RT are replaced by the low-order 32 bits of the temporary register.
Registers Altered
•RT
CR[CR0]
LT, GT, EQ, SO
if Rc contains 1
XER[SO, OV] if OE contains 1
Architecture Note
This instruction is part of the Multiply-Accumulate instruction set extensions and complies with the
architectural requirements for APUs of the IBM PowerPC Embedded Environment. As such, it is not
part of the PowerPC Architecture, nor is it part of the IBM PowerPC Embedded Environment.
Programs that use this instruction may not be portable to other implementations.
macchw RT, RA, RB OE=0, Rc=0
macchw. RT, RA, RB OE=0, Rc=1
macchwo RT, RA, RB OE=1, Rc=0
macchwo. RT, RA, RB OE=1, Rc=1
4 RT RA RB OE 172 Rc
0 6 11 16 21 22 31