AN2491 Freescale Semiconductor / Motorola, AN2491 Datasheet - Page 10

• Manufacturer Part Number: AN2491
• Description: Simplified Mnemonics for PowerPC Instructions
• Manufacturer: Freescale Semiconductor / Motorola

Branch Instruction Simplified Mnemonics
Branch Instruction Simplified Mnemonics
To identify a CR bit, an expression in which a CR field symbol is multiplied by 4 and then added to a
bit-number-within-CR-field symbol can be used, (for example, cr0 * 4 + eq).
4.5 Simplified Mnemonics that Incorporate the BO Operand
The mnemonics in Table 10 allow common BO operand encodings to be specified as part of the mnemonic,
along with the absolute address (AA) and set link register bits (LK). There are no simplified mnemonics for
relative and absolute unconditional branches. For these, the basic mnemonics b, ba, bl, and bla are used.
10
1
Branch unconditionally
Branch if condition true
Branch if condition false
Decrement CTR, branch if
CTR
Decrement CTR, branch if
CTR
Decrement CTR, branch if
CTR
Decrement CTR, branch if
CTR = 0
Decrement CTR, branch if
CTR = 0 and condition true
Decrement CTR, branch if
CTR = 0 and condition false
Simplified mnemonics for branch instructions that do not test CR bits should specify only a target. Otherwise a
programming error may occur.
Branch Semantics
0
0 and condition true
0 and condition false
1
1
1
Table 9. CR Field Identification Symbols (continued)
Simplified Mnemonics for PowerPC™ Instructions
Freescale Semiconductor, Inc.
bdnzt
bdnzf
For More Information On This Product,
bdnz
bdzt
bdzf
bdz
Table 10. Branch Simplified Mnemonics
bc
—
bt
bf
Symbol
LR Update Not Enabled
cr2
cr3
cr4
cr5
cr6
cr7
Go to: www.freescale.com
bdnzta
bdnzfa
bdnza
bdzta
bdzfa
bdza
bca
bta
bfa
—
bdnztlr
bdnzflr
bdnzlr
bdztlr
bdzflr
bdzlr
bclr
btlr
bflr
blr
bcctr
btctr
bfctr
bctr
BI[0–2]
—
—
—
—
—
—
010
011
100
101
110
111
bdnztl
bdnzfl
bdnzl
bdztl
bdzfl
bdzl
bcl
btl
bfl
—
CR Bits
40–43
44–47
48–51
52–55
56–59
60–63
LR Update Enabled
bdnztla
bdnzfla
bdnzla
bdztla
bdzfla
bdzla
bcla
btla
bfla
—
bdnztlrl
bdnzflrl
bdnzlrl
bdztlrl
bdzflrl
bdzlrl
bclrl
btlrl
bflrl
blrl
MOTOROLA
bcctrl
btctrl
bfctrl
bctrl
—
—
—
—
—
—