2 Commits

Author	SHA1	Message	Date
Andrew Kelley	886df772f0	stage2: LLVM backend: fix const packed structs ... When doing LLVM const bit shifting we must make sure the integer bit sizes are wide enough or else LLVM gives us a poison result.	2021-12-27 16:59:26 -07:00
Andrew Kelley	c8fb36b36c	stage2: LLVM backend: implement @tagName for enums ... Introduced a new AIR instruction: `tag_name`. Reasons to do this instead of lowering it in Sema to a switch, function call, array lookup, or if-else tower: * Sema is a bottleneck; do less work in Sema whenever possible. * If any optimization passes run, and the operand to becomes comptime-known, then it could change to have a comptime result value instead of lowering to a function or array or something which would then have to be garbage-collected. * Backends may want to choose to use a function and a switch branch, or they may want to use a different strategy. Codegen for `@tagName` is implemented for the LLVM backend but not any others yet. Introduced some new `Type` tags: * `const_slice_u8_sentinel_0` * `manyptr_const_u8_sentinel_0` The motivation for this was to make typeof() on the tag_name AIR instruction non-allocating. A bunch more enum tests are passing now.	2021-12-27 01:14:50 -07:00