Freescale Semiconductor PowerPC e500 Core, Reference Manual

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PowerPC e500 Core Family Reference Manual, Rev. 1
3-14 Freescale Semiconductor
Instruction Model
Although there is no subtract immediate instruction, its effect can be achieved by using an addi
instruction with the immediate operand negated. Simplified mnemonics are provided that include
this negation. Subtract instructions subtract the second operand (rA) from the third operand (rB).
Simplified mnemonics are provided in which the third operand is subtracted from the second. See
Appendix C, “Simplified Mnemonics for PowerPC Instructions ,” for examples.
According to Book E, an implementation that executes instructions with the overflow exception
enable bit (OE) set or that sets the carry bit (CA) can either execute these instructions slowly or
prevent execution of the subsequent instruction until the operation completes.
Chapter 4,
“Execution Timing ,” describes how the e500 handles CR dependencies. The summary overflow
(SO) and overflow (OV) bits in the XER are set to reflect an overflow condition of a 32-bit result
only if the instruction’s OE bit is set.
Table 3-6. Integer Arithmetic Instructions
Name Mnemonic Syntax
Add add
(
add. addo addo.
)
r D ,r A ,r B
Add Carrying addc
(
addc. addco addco.
)
r D ,r A ,r B
Add Extended adde ( adde. addeo addeo. ) r D ,r A ,r B
Add Immediate addi r D ,r A,SIMM
Add Immediate Carrying addic r D ,r A,SIMM
Add Immediate Carrying and Record addic. r D ,r A,SIMM
Add Immediate Shifted addis r D ,r A,SIMM
Add to Minus One Extended addme
(
addme. addmeo addmeo.
)
r D ,r A
Add to Zero Extended addze ( addze. addzeo addzeo. ) r D ,r A
Divide Word divw
(
divw. divwo divwo.
)
r D ,r A ,r B
Divide Word Unsigned divwu divwu. divwuo divwuo. r D ,r A ,r B
Multiply High Word mulhw ( mulhw. ) r D ,r A ,r B
Multiply High Word Unsigned mulhwu
(
mulhwu.
)
r D ,r A ,r B
Multiply Low Immediate mulli r D ,r A,SIMM
Multiply Low Word mullw ( mullw. mullwo mullwo. ) r D ,r A ,r B
Negate neg
(
neg. nego nego.
)
r D ,r A
Subtract From subf
(
subf. subfo subfo.
)
r D ,r A ,r B
Subtract from Carrying subfc ( subfc. subfco subfco. ) r D ,r A ,r B
Subtract from Extended subfe
(
subfe. subfeo subfeo.
)
r D ,r A ,r B
Subtract from Immediate Carrying subfic r D ,r A,SIMM
Subtract from Minus One Extended subfme ( subfme. subfmeo subfmeo. ) r D ,r A
Subtract from Zero Extended subfze
(
subfze. subfzeo subfzeo.
)
r D ,r A