Files
rust/tests/codegen-llvm
bors 873d4682c7 Auto merge of #151337 - the8472:bail-before-memcpy2, r=Mark-Simulacrum
optimize `vec.extend(slice.to_vec())`, take 2

Redoing https://github.com/rust-lang/rust/pull/130998
It was reverted in https://github.com/rust-lang/rust/pull/151150 due to flakiness. I have traced this to layout randomization perturbing the test (the failure reproduces locally with layout randomization), which is now excluded.
2026-01-25 19:45:35 +00:00
..
2025-11-08 10:57:35 -07:00
2025-08-15 16:42:21 +00:00

The files here use the LLVM FileCheck framework, documented at https://llvm.org/docs/CommandGuide/FileCheck.html.

One extension worth noting is the use of revisions as custom prefixes for FileCheck. If your codegen test has different behavior based on the chosen target or different compiler flags that you want to exercise, you can use a revisions annotation, like so:

// revisions: aaa bbb
// [bbb] compile-flags: --flags-for-bbb

After specifying those variations, you can write different expected, or explicitly unexpected output by using <prefix>-SAME: and <prefix>-NOT:, like so:

// CHECK: expected code
// aaa-SAME: emitted-only-for-aaa
// aaa-NOT:                        emitted-only-for-bbb
// bbb-NOT:  emitted-only-for-aaa
// bbb-SAME:                       emitted-only-for-bbb