The following table lists the POWER and PowerPC instructions that share the same op code on POWER and PowerPC platforms, but differ in their functional definition. Use caution when using these instructions in com assembly mode.
| POWER and PowerPC Instructions with Functional Differences | ||
| POWER | PowerPC | Description |
| dcs | sync | The sync instruction causes more pervasive synchronization in PowerPC than the dcs instruction does in POWER. |
| ics | isync | The isync instruction causes more pervasive synchronization in PowerPC than the ics instruction does in POWER. |
| svca | sc | In POWER, information from MSR is saved into CTR. In PowerPC, this information is saved into SRR1. PowerPC only supports one vector. POWER allows instruction fetching to continue at any of 128 locations. POWER saves the low-order 16 bits of the instruction in CTR. PowerPC does not save the low-order 16 bits of the instruction. |
| mtsri | mtsrin | POWER uses the RA field to compute the segment register number and, in some cases, the effective address (EA) is stored. PowerPC has no RA field, and the EA is not stored. |
| lsx | lswx | POWER does not alter the target register RT if the string length is 0. PowerPC leaves the contents of the target register RT undefined if the string length is 0. |
| mfsr | mfsr | This is a nonprivileged instruction in POWER. It is a privileged instruction in PowerPC. |
| mfmsr | mfmsr | This is a nonprivileged instruction in POWER. It is a privileged instruction in PowerPC. |
| mfdec | mfdec | The mfdec instruction is nonprivileged in POWER, but becomes a privileged instruction in PowerPC. As a result, the DEC encoding number for the mfdec instruction is different for POWER and PowerPC. |
| mffs | mffs | POWER sets the high-order 32 bits of the result to 0xFFFF FFFF . In PowerPC, the high-order 32 bits of the result are undefined. |
See "Incompatibilities with the POWER Architecture" in PowerPC Architecture for detailed information on functional differences for these instructions.
See "Features of the AIX Version 3.2.5 Assembler" for more information on the PowerPC-specific features of the assembler.
Migrating POWER and PowerPC Source Programs.
Differences between POWER and PowerPC Instructions with the Same Op Code.
POWER Instructions Deleted from PowerPC.
Instructions Available Only for the PowerPC 601 RISC Microprocessor.