Revision 1.0
285
Format:
vmulq vd, vs, vt
vmulq vd, vs, vt[e]
Description:
The 16-bit elements of vector register
vt
are multiplied on an element-by-element basis to the
elements of vector register
vs
, and loaded into the accumulator.
This instruction is specifically designed to support MPEG inverse quantization. The accumulator is
rounded if the product is negative, otherwise zero is added.
Bits 32...17 of the accumulator are clamped to 16 bit signed values and
AND
’d with 0xFFF0
(producing a result from -2048 to 2047 aligned to the short MSB), writing the results into vector
register
vd
.
If an element specification
e
is present for vector register
vt
, the selected scalar element(s) of
vt
is
used as described below.
VMULQ
MPEG Quantization
Vector Multiply
31
25
26
20
21
15
16
0
COP2
e
vt
6
4
5
0 1 0 0 1 0
VMULQ
1
1
5
5
vd
vs
5
10
6
11
6
VMULQ
0 0 0 0 1 1
24
Summary of Contents for Ultra64
Page 2: ...2 ...
Page 10: ...10 ...
Page 12: ...12 Figure 6 2 buildtask Operation 137 ...
Page 14: ...14 ...
Page 80: ...80 Vector Unit Instructions vmadm dres_int dres_int vconst 3 vmadn dres_frac vconst vconst 0 ...
Page 104: ...104 RSP Coprocessor 0 ...
Page 150: ...150 Advanced Information ...
Page 155: ...Revision 1 0 155 ...
Page 248: ...248 Exceptions None ...
Page 251: ...Revision 1 0 251 Exceptions None ...
Page 254: ...254 Exceptions None ...
Page 257: ...Revision 1 0 257 Exceptions None ...
Page 293: ...Revision 1 0 293 Exceptions None ...
Page 316: ...316 Exceptions None ...