Enable f16 in assembly on aarch64 platforms that support it

[lengrongfu]

Issue: #125398

About pr: #126070

[rustbot]

r? @lcnr

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[lengrongfu]

r? @tgross35

[rustbot]

Failed to set assignee to tgross35: invalid assignee

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[beetrees]

r? @Amanieu since you reviewed the other f16 inline ASM PRs.

[rust-log-analyzer]

The job x86_64-gnu-llvm-17 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 46)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 49)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 61)
##[endgroup]
Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
[CI_JOB_NAME=x86_64-gnu-llvm-17]
---
sccache: Starting the server...
##[group]Configure the build
configure: processing command line
configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-17', '--enable-llvm-link-shared', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'change-id=99999999', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--enable-new-symbol-mangling']
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-17/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.thin-lto-import-instr-limit := 10
configure: change-id            := 99999999
---
failures:

---- [assembly] tests/assembly/asm/aarch64-types.rs#arm64ec stdout ----

error in revision `arm64ec`: compilation failed!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/assembly/asm/aarch64-types.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "--cfg" "arm64ec" "--check-cfg" "cfg(FALSE,aarch64,arm64ec)" "-O" "-Cdebug-assertions=no" "--emit" "asm" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/assembly/asm/aarch64-types.arm64ec/aarch64-types.s" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/assembly/asm/aarch64-types.arm64ec/auxiliary" "--target" "arm64ec-pc-windows-msvc"
--- stderr -------------------------------
error: unexpected end of macro invocation
##[error]   --> /checkout/tests/assembly/asm/aarch64-types.rs:179:29
    |
    |
119 | macro_rules! check {
    | ------------------ when calling this macro
...
179 | check!(reg_f16 f16 reg "mov");
    |                             ^ missing tokens in macro arguments
    |
note: while trying to match meta-variable `$modifier:literal`
    |
    |
120 |     ($func:ident $ty:ident $class:ident $mov:literal $modifier:literal) => {

warning: unexpected `cfg` condition name: `neon`
##[warning]   --> /checkout/tests/assembly/asm/aarch64-types.rs:275:7
    |
    |
275 | #[cfg(neon)]
    |       ^^^^ help: found config with similar value: `target_feature = "neon"`
    |
    = help: expected names are: `FALSE`, `aarch64`, `arm64ec`, `clippy`, `debug_assertions`, `doc`, `doctest`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `rustfmt`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, and `windows`
    = help: to expect this configuration use `--check-cfg=cfg(neon)`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration

warning: unexpected `cfg` condition name: `neon`
##[warning]   --> /checkout/tests/assembly/asm/aarch64-types.rs:282:7
    |
    |
282 | #[cfg(neon)]
    |       ^^^^ help: found config with similar value: `target_feature = "neon"`
    |
    = help: to expect this configuration use `--check-cfg=cfg(neon)`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
error: aborting due to 1 previous error; 2 warnings emitted
------------------------------------------



---- [assembly] tests/assembly/asm/aarch64-types.rs#aarch64 stdout ----

error in revision `aarch64`: compilation failed!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/assembly/asm/aarch64-types.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "--cfg" "aarch64" "--check-cfg" "cfg(FALSE,aarch64,arm64ec)" "-O" "-Cdebug-assertions=no" "--emit" "asm" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/assembly/asm/aarch64-types.aarch64/aarch64-types.s" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/assembly/asm/aarch64-types.aarch64/auxiliary" "--target" "aarch64-unknown-linux-gnu"
--- stderr -------------------------------
error: unexpected end of macro invocation
##[error]   --> /checkout/tests/assembly/asm/aarch64-types.rs:179:29
    |
    |
119 | macro_rules! check {
    | ------------------ when calling this macro
...
179 | check!(reg_f16 f16 reg "mov");
    |                             ^ missing tokens in macro arguments
    |
note: while trying to match meta-variable `$modifier:literal`
    |
    |
120 |     ($func:ident $ty:ident $class:ident $mov:literal $modifier:literal) => {

warning: unexpected `cfg` condition name: `neon`
##[warning]   --> /checkout/tests/assembly/asm/aarch64-types.rs:275:7
    |
    |
275 | #[cfg(neon)]
    |       ^^^^ help: found config with similar value: `target_feature = "neon"`
    |
    = help: expected names are: `FALSE`, `aarch64`, `arm64ec`, `clippy`, `debug_assertions`, `doc`, `doctest`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `rustfmt`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, and `windows`
    = help: to expect this configuration use `--check-cfg=cfg(neon)`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration

warning: unexpected `cfg` condition name: `neon`
##[warning]   --> /checkout/tests/assembly/asm/aarch64-types.rs:282:7
    |
    |
282 | #[cfg(neon)]
    |       ^^^^ help: found config with similar value: `target_feature = "neon"`
    |
    = help: to expect this configuration use `--check-cfg=cfg(neon)`
    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
error: aborting due to 1 previous error; 2 warnings emitted
------------------------------------------

[tgross35]

I don't think these neon labels are actually getting tested, you need to add neon in the //@ revisions: list at the top and make sure --cfg neon gets passed for at least one of the tests (like

rust/tests/assembly/asm/arm-types.rs

Lines 1 to 7 in 2495953

	//@ revisions: base d32 neon
	//@ assembly-output: emit-asm
	//@ compile-flags: --target armv7-unknown-linux-gnueabihf
	//@ compile-flags: -C opt-level=0
	//@[d32] compile-flags: -C target-feature=+d32
	//@[neon] compile-flags: -C target-feature=+neon --cfg d32
	//@[neon] filecheck-flags: --check-prefix d32

)

I'm not sure what combinations it makes sense to test, there's also a fp16 target feature. Cc @workingjubilee since you did some work on neon and flags

[beetrees]

The neon target feature is enabled by default on aarch64-unknown-linux-gnu and arm64ec-pc-windows-msvc, so there's no need to have any cfg unless it's been explicitly disabled.

However, once the cfg is removed there might be compilation failures on arm64ec-pc-windows-msvc due to llvm/llvm-project#94434, in which case the options are to either change the check! macro to not pass/return f16 by value or just cfg(aarch64) the f16 test cases and leave a FIXME(f16_f128) comment.

[tgross35]

@rustbot label +F-f16_and_f128

[Amanieu]

@rustbot author

[tgross35]

@lengrongfu are you still interested in working on this? No problem if not, somebody else may be able to pick up your work and get it over the line.

[lengrongfu]

Sorry, I don't have enough time to fix this.