6606b88136
* Add a pre-opt optimization to change constants into immediates. This converts 'iadd' + 'iconst' into 'iadd_imm', and so on. * Optimize away redundant `bint` instructions. Cretonne has a concept of "Testable" values, which can be either boolean or integer. When the an instruction needing a "Testable" value receives the result of a `bint`, converting boolean to integer, eliminate the `bint`, as it's redundant. * Postopt: Optimize using CPU flags. This introduces a post-legalization optimization pass which converts compare+branch sequences to use flags values on CPUs which support it. * Define a form of x86's `urm` that doesn't clobber FLAGS. movzbl/movsbl/etc. don't clobber FLAGS; define a form of the `urm` recipe that represents this. * Implement a DCE pass. This pass deletes instructions with no side effects and no results that are used. * Clarify ambiguity about "32-bit" and "64-bit" in comments. * Add x86 encodings for icmp_imm. * Add a testcase for postopt CPU flags optimization. This covers the basic functionality of transforming compare+branch sequences to use CPU flags. * Pattern-match irsub_imm in preopt.
This crate contains the core Cretonne code generator. It translates code from an intermediate representation into executable machine code.