4 ms·
* I do not have precise references, but I have read somewhere that RISC-V actually has a very good code density, often better than x86 itself. * Well, only a f
by giomasce 8y ago
* I do not have precise references, but I have read somewhere that RISC-V actually has a very good code density, often better than x86 itself.
* Well, only a few of the 8192 combinations are actually meaningful. It is clear that most implementations will converge on few configurations, leaving the others for specialized domains.
- brandmeyer 8y ago> I do not have precise references, but I have read somewhere that RISC-V actually has a very good code density, often better than x86 itself. Unfortunately, that which the headlines giveth, the implementation details taketh away. The bulk of the savings come from loads and stores to the stack. The remainder of the savings is for destructive integer ops on a subset of only 8 registers. So sure, if your code can be efficiently described using those restrictions, then you'll have great code density! Many commercial codes do have short stretches that fit this requirement, but they are interspersed with stretches that don't. This makes it very hard to produce an effective code size benchmark for RISC-V, because it is so heavily load dependent.
- Someone 8y agoIf you start from scratch today, you better beat x86. x86 wastes instruction space for 8087 floating point operations, for vector extensions that have been superseded by better ones, requires prefixes to operate on what nowadays are standard argument sizes, etc.