Instruction Set And Addressing Modes; Powerpc Instruction Set And Addressing Modles; Instruction Set - IBM PowerPC 604 User Manual

• Perfonnance monitor counter registers (PMCl and PMC2). The counters are used
to record the number of times a certain event has occurred.
• Monitor mode control register 0 (MMCRO)-This is used for enabling various
performance monitoring interrupt conditions and establishes the function of the
counters.
• Sampled instruction address and sampled data address registers (SIA and
SDA)-These registers hold the addresses for instruction and data used by the
performance monitoring interrupt.
Note that while it is not guaranteed that the HID registers, or other implementation-specific
registers, be consistent among PowerPC processors.
1.3.3 Instruction Set and Addressing Modes
The following subsections describe the PowerPC instruction set and addressing modes in
general.
1.3.3.1 PowerPC Instruction Set and Addressing Modes
All PowerPC instructions are encoded as single-word (32-bit) opcodes. Instruction formats
are consistent among all instruction types, permitting efficient decoding to occur in parallel
with operand accesses. This fixed instruction length and consistent format greatly
simplifies instruction pipelining.
1.3.3.1.1 Instruction Set
The 604 implements the entire PowerPC instruction set (for 32-bit implementations) and
most optional PowerPC instructions. The PowerPC instructions can be loosely grouped
into the following general categories:
• Integer instructions-These include computational and logical instructions.
- Integer arithmetic instructions
- Integer compare instructions
- Logical instructions
- Integer rotate and shift instructions
• Floating-point instructions-These include floating-point computational
instructions, as well as instructions that affect the FPSCR. Floating-point
instructions include the following:
- Floating-point arithmetic instructions
- Floating-point multiply/add instructions
- Floating-point rounding and conversion instructions
- Floating-point compare instructions
- Floating-point move instructions
- Floating-point status and control instructions
- Optional floating-point instructions (listed with the optional instructions below)
Chapter 1. Overview
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