Table 6-8, Floating-point instructions – IBM POWERPC 750GL User Manual

Page 242

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User’s Manual
IBM PowerPC 750GX and 750GL RISC Microprocessor

Instruction Timing

Page 242 of 377

gx_06.fm.(1.2)

March 27, 2006

Table 6-8 shows latencies for floating-point instructions. Pipelined floating-point instructions are shown with
the number of clocks in each pipeline stage separated by dashes. Floating-point instructions with a single
entry in the cycles column are not pipelined. When the FPU executes these nonpipelined instructions, it
remains busy for the full duration of the instruction execution and is not available for subsequent instructions.

Subtract From Carrying

subfc[o][.]

31

8

IU1/IU2

1

Subtract From

Extended

subfe[o][.]

31

136

IU1/IU2

1

Execution

Subtract From

Immediate Carrying

subfic

8

IU1/IU2

1

Subtract From Minus

One Extended

subfme[o][.]

31

232

IU1/IU2

1

Execution

Subtract From Zero

Extended

subfze[o][.]

31

200

IU1/IU2

1

Execution

Subtract From

subf[.]

31

40

IU1/IU2

1

Trap Word

tw

31

4

IU1/IU2 2

Trap Word Immediate

twi

3

IU1/IU2

2

XOR Immediate

xori

26

IU1/IU2

1

XOR Immediate Shifted

xoris

27

IU1/IU2

1

XOR

xor[.]

31

316

IU1/IU2

1

Table 6-8. Floating-Point Instructions

(Page 1 of 2)

Instruction

Mnemonic

Primary
Opcode

Extended

Opcode

Unit

Cycles

Serialization

Floating Absolute Value

fabs[.]

63

264

FPU

1-1-1

Floating Add Single

fadds[.]

59

21

FPU

1-1-1

Floating Add

fadd[.]

63

21

FPU

1-1-1

Floating Compare

Ordered

fcmpo

63

32

FPU

1-1-1

Floating Compare

Unordered

fcmpu

63

0

FPU

1-1-1

Floating Convert To

Integer Word with

Round toward Zero

fctiwz[.]

63

15

FPU

1-1-1

Floating Convert To

Integer Word

fctiw[.]

63

14

FPU

1-1-1

Floating Divide Single

fdivs[.]

59

18

FPU

17

Floating Divide

fdiv[.]

63

18

FPU

31

Floating Multiply-Add

Single

fmadds[.]

59

29

FPU

1-1-1

Floating Multiply-Add

fmadd[.]

63

29

FPU

2-1-1

Floating Move Register

fmr[.]

63

72

FPU

1-1-1

Table 6-7. Integer Instructions

(Page 3 of 3)

Instruction

Mnemonic

Primary
Opcode

Extended

Opcode

Unit

Cycles

Serialization

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