Chapter 1. Overview
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Instruction Set
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Processor control instructionsThese instructions are used for synchronizing
memory accesses and management of caches, TLBs, and the segment registers.
Move to/from SPR instructions
Move to/from MSR
Synchronize
Instruction synchronize
Order loads and stores
Memory control instructionsThese instructions provide control of caches, TLBs,
and SRs.
Supervisor-level cache management instructions
User-level cache instructions
Segment register manipulation instructions
Translation lookaside buffer management instructions
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This grouping does not indicate the execution unit that executes a particular instruction or
group of instructions.
Integer instructions operate on byte, half-word, and word operands. Floating-point
instructions operate on single-precision (one word) and double-precision (one double
word) oating-point operands. The PowerPC architecture uses instructions that are four
bytes long and word-aligned. It provides for byte, half-word, and word operand loads and
stores between memory and a set of 32 GPRs. It also provides for word and double-word
operand loads and stores between memory and a set of 32 oating-point registers (FPRs).
Computational instructions do not modify memory. To use a memory operand in a
computation and then modify the same or another memory location, the memory contents
must be loaded into a register, modiTed, and then written back to the target location with
distinct instructions.
PowerPC processors follow the program ow when they are in the normal execution state.
However, the ow of instructions can be interrupted directly by the execution of an
instruction or by an asynchronous event. Either kind of exception may cause one of several
components of the system software to be invoked.
Effective address computations for both data and instruction accesses use 32-bit unsigned
binary arithmetic. A carry from bit 0 is ignored in 32-bit implementations.