diff --git a/tests/assembly/s390x-backchain-toggle.rs b/tests/assembly/s390x-backchain-toggle.rs new file mode 100644 index 00000000000..8b6d0cf2123 --- /dev/null +++ b/tests/assembly/s390x-backchain-toggle.rs @@ -0,0 +1,46 @@ +//@ revisions: enable-backchain disable-backchain +//@ assembly-output: emit-asm +//@ compile-flags: -O --crate-type=lib --target=s390x-unknown-linux-gnu +//@ needs-llvm-components: systemz +//@[enable-backchain] compile-flags: -Ctarget-feature=+backchain +//@[disable-backchain] compile-flags: -Ctarget-feature=-backchain +#![feature(no_core, lang_items)] +#![no_std] +#![no_core] + +#[lang = "sized"] +trait Sized {} + +extern "C" { + fn extern_func(); +} + +// CHECK-LABEL: test_backchain +#[no_mangle] +extern "C" fn test_backchain() -> i32 { + // Here we try to match if backchain register is saved to the parameter area (stored in r15/sp) + // And also if a new parameter area (160 bytes) is allocated for the upcoming function call + // enable-backchain: lgr [[REG1:.*]], %r15 + // enable-backchain-NEXT: aghi %r15, -160 + // enable-backchain: stg [[REG1]], 0(%r15) + // disable-backchain: aghi %r15, -160 + // disable-backchain-NOT: stg %r{{.*}}, 0(%r15) + unsafe { + extern_func(); + } + // enable-backchain-NEXT: brasl %r{{.*}}, extern_func@PLT + // disable-backchain: brasl %r{{.*}}, extern_func@PLT + + // Make sure that the expected return value is written into %r2 (return register): + // enable-backchain-NEXT: lghi %r2, 1 + // disable-backchain: lghi %r2, 0 + #[cfg(target_feature = "backchain")] + { + 1 + } + #[cfg(not(target_feature = "backchain"))] + { + 0 + } + // CHECK: br %r{{.*}} +}