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Instruction Selection

Instructions on a RISC architecture are structured in a systematic way. They can be categorized into ALU operations, memory operations, and control operations. ALU operations always work on registers, and every register from the register set can be addressed by every ALU operation. Memory operations move values between the register set and memory. This structure makes instruction selection relatively easy, and the Java data types map 1:1 to the instruction architecture.

The optimal selection of instructions is more complex on x86 than it is on Alpha for the following reasons:


next up previous
Next: Instruction Patching Up: Modified Optimizations Previous: Register Allocation