add2976a9b
Runtime `@shuffle` has two cases which backends generally want to handle differently for efficiency: * One runtime vector operand; some result elements may be comptime-known * Two runtime vector operands; some result elements may be undefined The latter case happens if both vectors given to `@shuffle` are runtime-known and they are both used (i.e. the mask refers to them). Otherwise, if the result is not entirely comptime-known, we are in the former case. `Sema` now diffentiates these two cases in the AIR so that backends can easily handle them however they want to. Note that this *doesn't* really involve Sema doing any more work than it would otherwise need to, so there's not really a negative here! Most existing backends have their lowerings for `@shuffle` migrated in this commit. The LLVM backend uses new lowerings suggested by Jacob as ones which it will handle effectively. The x86_64 backend has not yet been migrated; for now there's a panic in there. Jacob will implement that before this is merged anywhere.
Test Case Quick Reference
Use comments at the end of the file to indicate metadata about the test case. Here are examples of different kinds of tests:
Compile Error Test
If you want it to be run with zig test and match expected error messages:
// error
// is_test=true
//
// :4:13: error: 'try' outside function scope
Execution
This will do zig run on the code and expect exit code 0.
// run
Translate-c
If you want to test translating C code to Zig use translate-c:
// translate-c
// c_frontend=aro,clang
// target=x86_64-linux
//
// pub const foo = 1;
// pub const immediately_after_foo = 2;
//
// pub const somewhere_else_in_the_file = 3:
Run Translated C
If you want to test translating C code to Zig and then executing it use run-translated-c:
// run-translated-c
// c_frontend=aro,clang
// target=x86_64-linux
//
// Hello world!
Incremental Compilation
Make multiple files that have ".", and then an integer, before the ".zig" extension, like this:
hello.0.zig
hello.1.zig
hello.2.zig
Each file can be a different kind of test, such as expecting compile errors, or expecting to be run and exit(0). The test harness will use these to simulate incremental compilation.
At the time of writing there is no way to specify multiple files being changed as part of an update.
Subdirectories
Subdirectories do not have any semantic meaning but they can be used for organization since the test harness will recurse into them. The full directory path will be prepended as a prefix on the test case name.
Limiting which Backends and Targets are Tested
// run
// backend=stage2,llvm
// target=x86_64-linux,x86_64-macos
Possible backends are:
stage1: equivalent to-fstage1.stage2: equivalent to passing-fno-stage1 -fno-LLVM.llvm: equivalent to-fLLVM -fno-stage1.