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2-46
MPC7400 RISC Microprocessor Users Manual
Instruction Set Summary
2.3.4.2 Floating-Point Instructions
This section describes the oating-point instructions, which include the following:
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Floating-point arithmetic instructions
Floating-point multiply-add instructions
Floating-point rounding and conversion instructions
Floating-point compare instructions
Floating-point status and control register instructions
Floating-point move instructions
See Section 2.3.4.3, òLoad and Store Instructions,ó for information about oating-point
loads and stores.
The PowerPC architecture supports a oating-point system as deTned in the IEEE 754
standard, but requires software support to conform with that standard. All oating-point
operations conform to the IEEE 754 standard, except if software sets the non-IEEE mode
FPSCR[NI].
2.3.4.2.1 Floating-Point Arithmetic Instructions
The oating-point arithmetic instructions are summarized in Table 2-24.
Table 2-24. Floating-Point Arithmetic Instructions
Table 2-23. Integer Shift Instructions
Name
Mnemonic
Syntax
Shift Left Word
slw
(
slw.
)
r
A
,r
S
,r
B
Shift Right Word
srw
(
srw.
)
r
A
,r
S
,r
B
Shift Right Algebraic Word Immediate
srawi
(
srawi.
)
r
A
,r
S
,
SH
Shift Right Algebraic Word
sraw
(
sraw.
)
r
A
,r
S
,r
B
Name
Mnemonic
Syntax
Floating Add (Double-Precision)
fadd
(
fadd.
)
fr
D
,fr
A
,fr
B
Floating Add Single
fadds
(
fadds.
)
fr
D
,fr
A
,fr
B
Floating Subtract (Double-Precision)
fsub
(
fsub.
)
fr
D
,fr
A
,fr
B
Floating Subtract Single
fsubs
(
fsubs.
)
fr
D
,fr
A
,fr
B
Floating Multiply
(Double-Precision)
fmul
(
fmul.
)
fr
D
,fr
A
,fr
C
Floating Multiply
Single
fmuls
(
fmuls.
)
fr
D
,fr
A
,fr
C
Floating Divide (Double-Precision)
fdiv
(
fdiv.
)
fr
D
,fr
A
,fr
B
Floating Divide Single
fdivs
(
fdivs.
)
fr
D
,fr
A
,fr
B
Floating Reciprocal Estimate Single
1
1
These instructions are optional in the PowerPC architecture.
fres
(
fres.
)
fr
D
,fr
B
Floating Reciprocal Square Root Estimate
1
frsqrte
(
frsqrte.
)
fr
D
,fr
B
Floating Select
1
fsel
fr
D,
fr
A,
fr
C,
fr
B