Add floating point inline ASM support for SPARC

[beetrees]

This PR adds support for floating point registers to SPARC inline ASM.

Ping target maintainers: @psumbera @kulikjak @jonathanpallant @mvolfik @he32 @0323pin @semarie

Tracking issues:
f16 inline ASM: #125398 (part of #116909)
SPARC inline ASM: #93335

[rustbot]

rustc_codegen_gcc is developed in its own repository. If possible, consider making this change to rust-lang/rustc_codegen_gcc instead.

cc @antoyo, @GuillaumeGomez

[rustbot]

r? @petrochenkov

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[rust-log-analyzer]

The job aarch64-gnu-llvm-21-1 failed! Check out the build log: (web) (plain enhanced) (plain)

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

---- [assembly] tests/assembly-llvm/asm/sparc-types.rs#sparc stdout ----
------rustc stdout------------------------------

------rustc stderr------------------------------
rustc-LLVM ERROR: SPARCv8 does not handle f128 in calls; pass indirectly

------------------------------------------

error in revision `sparc`: compilation failed!
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/assembly-llvm/asm/sparc-types.rs" "-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/aarch64-unknown-linux-gnu/stage2" "--cfg" "sparc" "--check-cfg" "cfg(test,FALSE,sparc,sparcv8plus,sparc64)" "-O" "-Cdebug-assertions=no" "-Zcodegen-source-order" "--emit" "asm" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/assembly-llvm/asm/sparc-types.sparc/sparc-types.s" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Cpanic=abort" "-Cforce-unwind-tables=yes" "--target" "sparc-unknown-none-elf" "-Zmerge-functions=disabled" "--check-cfg=cfg(v9)" "--extern" "minicore=/checkout/obj/build/aarch64-unknown-linux-gnu/test/assembly-llvm/asm/sparc-types.sparc/libminicore.rlib"
stdout: none
--- stderr -------------------------------
rustc-LLVM ERROR: SPARCv8 does not handle f128 in calls; pass indirectly
------------------------------------------

---- [assembly] tests/assembly-llvm/asm/sparc-types.rs#sparc stdout end ----
---- [assembly] tests/assembly-llvm/asm/sparc-types.rs#sparcv8plus stdout ----
------rustc stdout------------------------------

------rustc stderr------------------------------
rustc-LLVM ERROR: SPARCv8 does not handle f128 in calls; pass indirectly

------------------------------------------

error in revision `sparcv8plus`: compilation failed!
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/assembly-llvm/asm/sparc-types.rs" "-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/aarch64-unknown-linux-gnu/stage2" "--cfg" "sparcv8plus" "--check-cfg" "cfg(test,FALSE,sparc,sparcv8plus,sparc64)" "-O" "-Cdebug-assertions=no" "-Zcodegen-source-order" "--emit" "asm" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/assembly-llvm/asm/sparc-types.sparcv8plus/sparc-types.s" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Cpanic=abort" "-Cforce-unwind-tables=yes" "--target" "sparc-unknown-linux-gnu" "--cfg" "v9" "-Zmerge-functions=disabled" "--check-cfg=cfg(v9)" "--extern" "minicore=/checkout/obj/build/aarch64-unknown-linux-gnu/test/assembly-llvm/asm/sparc-types.sparcv8plus/libminicore.rlib"
stdout: none
--- stderr -------------------------------
rustc-LLVM ERROR: SPARCv8 does not handle f128 in calls; pass indirectly
------------------------------------------

---- [assembly] tests/assembly-llvm/asm/sparc-types.rs#sparcv8plus stdout end ----

failures:

[folkertdev]

Sparc handles f128 starting from LLVM 22. We'll drop LLVM 21 support soon, so it's fine to restrict that test to LLVM 22 and higher with //@ min-llvm-version: 22.

[folkertdev]

probably good to add tests/ui/asm/sparc/bad-reg.rs to check that this errors correctly.

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