Mpydp – Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 205

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Multiply Two Double-Precision Floating-Point Values

MPYDP

3-145

Instruction Set

SPRU733

Multiply Two Double-Precision Floating-Point Values

MPYDP

Syntax

MPYDP (.unit) src1, src2, dst

.unit = .M1 or .M2

Compatibility

C67x and C67x+ CPU

Opcode

31

29

28

27

23

22

18

17

13

12

11

7

6

5

4

3

2

1

0

creg

z

dst

src2

src1

x 0 1 1 1 0 0 0 0 0 0 s p

3

1

5

5

5

1

1

1

Opcode map field used...

For operand type...

Unit

src1
src2
dst

dp
dp
dp

.M1, .M2

Description

The src1 operand is multiplied by the src2 operand. The result is placed in dst.

Execution

if (cond)

src1  src2dst

else

nop

Notes:
1) If one source is SNaN or QNaN, the result is a signed NaN_out. If either

source is SNaN, the INVAL bit is set also. The sign of NaN_out is the
exclusive-OR of the input signs.

2) Signed infinity multiplied by signed infinity or a normalized number (other

than signed 0) returns signed infinity. Signed infinity multiplied by
signed 0 returns a signed NaN_out and sets the INVAL bit.

3) If one or both sources are signed 0, the result is signed 0 unless the other

source is NaN or signed infinity, in which case the result is signed
NaN_out.

4) A denormalized source is treated as signed 0 and the DENn bit is set.

The INEX bit is set except when the other source is signed infinity, signed
NaN, or signed 0. Therefore, a signed infinity multiplied by a denormal-
ized number gives a signed NaN_out and sets the INVAL bit.

5) If rounding is performed, the INEX bit is set.

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