Contributors:
- Leehod Baruch
- Mircea Namolaru
Delivery Date:
- 2005-05-30
Dependencies:
- combine (RTL)
- gcse (RTL)
Description:
- Optimization targeted to 64-bit code.
- 32 bit computations on a 64 bit machine, require generation of sign extension instructions
- to ensure the correctness of the computation. A possible policy (currently implemented in GCC) is to generate a sign extension after each 32 bit computation. Depending on the instruction set of the architecture some of these sign extension instructions may be redundant.
- Risks: Uses optimizations implemented in RTL (see dependancies).
JohnYates describes the notably successful approach that the Apollo Computer compiler suite took to this problem.