rustc_target: update x86_win64 to match the documented calling convention for f128

[durin42]

llvm/llvm-project@5ee1c0b updates llvm to match the documented calling convention to pass f128 indirectly. This change makes us do that on all versions of LLVM, not just starting with LLVM 21.

@rustbot label llvm-main

try-job: dist-x86_64-msvc
try-job: dist-x86_64-mingw
try-job: x86_64-msvc-1
try-job: x86_64-msvc-2
try-job: x86_64-mingw-1
try-job: x86_64-mingw-2

[rustbot]

r? @Mark-Simulacrum

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[Mark-Simulacrum]

r? @tgross35

Looks OK but want to get someone more familiar with i128 to review.

[tgross35]

I meant to send a patch once my LLVM change merged, but we should also update our codegen to match. Could you change

rust/compiler/rustc_target/src/callconv/x86_win64.rs

Lines 26 to 43 in 8279176

	if is_ret && matches!(scalar.primitive(), Primitive::Int(Integer::I128, _)) {
	if cx.target_spec().rustc_abi == Some(RustcAbi::X86Softfloat) {
	// Use the native `i128` LLVM type for the softfloat ABI -- in other words, adjust nothing.
	} else {
	// `i128` is returned in xmm0 by Clang and GCC
	// FIXME(#134288): This may change for the `-msvc` targets in the future.
	let reg = Reg { kind: RegKind::Vector, size: Size::from_bits(128) };
	a.cast_to(reg);
	}
	} else if a.layout.size.bytes() > 8
	&& !matches!(scalar.primitive(), Primitive::Float(Float::F128))
	{
	// Match what LLVM does for `f128` so that `compiler-builtins` builtins match up
	// with what LLVM expects.
	a.make_indirect();
	} else {
	a.extend_integer_width_to(32);
	}

so i128 and f128 use the same ABI? That probably means a codegen test update.

[tgross35]

You should be able to take the CC change from #137779.

[tgross35]

@bors try

r=me once that passes

[bors]

⌛ Trying commit 8399166 with merge b83a6ea...

[rust-log-analyzer]

The job x86_64-msvc-1 failed! Check out the build log: (web) (plain)

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

Updating files:  98% (51625/52678)
Updating files:  99% (52152/52678)
Updating files: 100% (52678/52678)
Updating files: 100% (52678/52678), done.
branch 'try' set up to track 'origin/try'.
Switched to a new branch 'try'
##[endgroup]
[command]"C:\Program Files\Git\bin\git.exe" log -1 --format=%H
b83a6eafbdd52274a6bfc4df04b88ef0e424bb02
##[group]Run src/ci/scripts/setup-environment.sh
src/ci/scripts/setup-environment.sh
---
file:.git/config remote.origin.url=https://github.com/rust-lang-ci/rust
file:.git/config remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
file:.git/config gc.auto=0
file:.git/config http.https://github.com/.extraheader=AUTHORIZATION: basic ***
file:.git/config branch.try.remote=origin
file:.git/config branch.try.merge=refs/heads/try
file:.git/config remote.upstream.url=https://github.com/rust-lang/rust
file:.git/config remote.upstream.fetch=+refs/heads/*:refs/remotes/upstream/*
file:.git/config submodule.library/backtrace.active=true
file:.git/config submodule.library/backtrace.url=https://github.com/rust-lang/backtrace-rs.git
file:.git/config submodule.library/stdarch.active=true
---
---- [ui] tests\ui\float\conv-bits-runtime-const.rs stdout ----

error: test run failed!
status: exit code: 0xc0000005
command: PATH="D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage2\lib\rustlib\x86_64-pc-windows-msvc\lib;C:\Program Files (x86)\Windows Kits\10\bin\x64;C:\Program Files (x86)\Windows Kits\10\bin\10.0.26100.0\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\bin\HostX64\x64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\bin\HostX64\x64;D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage0-bootstrap-tools\x86_64-pc-windows-msvc\release\deps;D:\a\rust\rust\build\x86_64-pc-windows-msvc\stage0\bin;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Users\runneradmin\bin;D:\a\rust\rust\ninja;D:\a\rust\rust\sccache;C:\Program Files\MongoDB\Server\7.0\bin;C:\vcpkg;C:\tools\zstd;C:\hostedtoolcache\windows\stack\3.3.1\x64;C:\cabal\bin;C:\ghcup\bin;C:\mingw64\bin;C:\Program Files\dotnet;C:\Program Files\MySQL\MySQL Server 8.0\bin;C:\Program Files\R\R-4.4.2\bin\x64;C:\SeleniumWebDrivers\GeckoDriver;C:\SeleniumWebDrivers\EdgeDriver;C:\SeleniumWebDrivers\ChromeDriver;C:\Program Files (x86)\sbt\bin;C:\Program Files (x86)\GitHub CLI;C:\Program Files\Git\usr\bin;C:\Program Files (x86)\pipx_bin;C:\npm\prefix;C:\hostedtoolcache\windows\go\1.23.7\x64\bin;C:\hostedtoolcache\windows\Python\3.9.13\x64\Scripts;C:\hostedtoolcache\windows\Python\3.9.13\x64;C:\hostedtoolcache\windows\Ruby\3.3.7\x64\bin;C:\Program Files\OpenSSL\bin;C:\tools\kotlinc\bin;C:\hostedtoolcache\windows\Java_Temurin-Hotspot_jdk\17.0.14-7\x64\bin;C:\Program Files\ImageMagick-7.1.1-Q16-HDRI;C:\Program Files\Microsoft SDKs\Azure\CLI2\wbin;C:\ProgramData\kind;C:\ProgramData\Chocolatey\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files\PowerShell\7;C:\Program Files\Microsoft\Web Platform Installer;C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\170\Tools\Binn;C:\Program Files\Microsoft SQL Server\150\Tools\Binn;C:\Program Files\dotnet;C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit;C:\Program Files (x86)\WiX Toolset v3.14\bin;C:\Program Files\Microsoft SQL Server\130\DTS\Binn;C:\Program Files\Microsoft SQL Server\140\DTS\Binn;C:\Program Files\Microsoft SQL Server\150\DTS\Binn;C:\Program Files\Microsoft SQL Server\160\DTS\Binn;C:\ProgramData\chocolatey\lib\pulumi\tools\Pulumi\bin;C:\Program Files\CMake\bin;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.9.9\bin;C:\Program Files\Microsoft Service Fabric\bin\Fabric\Fabric.Code;C:\Program Files\Microsoft SDKs\Service Fabric\Tools\ServiceFabricLocalClusterManager;C:\Program Files\nodejs;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\GitHub CLI;C:\tools\php;C:\Program Files (x86)\sbt\bin;C:\Program Files\Amazon\AWSCLIV2;C:\Program Files\Amazon\SessionManagerPlugin\bin;C:\Program Files\Amazon\AWSSAMCLI\bin;C:\Program Files\Microsoft SQL Server\130\Tools\Binn;C:\Program Files\mongosh;C:\Program Files\LLVM\bin;C:\Program Files (x86)\LLVM\bin;C:\Users\runneradmin\.dotnet\tools;C:\Users\runneradmin\.cargo\bin;C:\Users\runneradmin\AppData\Local\Microsoft\WindowsApps;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.43.34808\bin\HostX64\x64" "D:\\a\\rust\\rust\\build\\x86_64-pc-windows-msvc\\test\\ui\\float\\conv-bits-runtime-const\\a.exe"
stdout: none
stderr: none



failures:
    [ui] tests\ui\float\conv-bits-runtime-const.rs

test result: FAILED. 18523 passed; 1 failed; 282 ignored; 0 measured; 23 filtered out; finished in 1040.18s

Some tests failed in compiletest suite=ui mode=ui host=x86_64-pc-windows-msvc target=x86_64-pc-windows-msvc
Build completed unsuccessfully in 1:33:54
make: *** [Makefile:113: ci-msvc-py] Error 1
  local time: Tue Apr  1 07:46:26 CUT 2025
  network time: Tue, 01 Apr 2025 07:46:26 GMT
##[error]Process completed with exit code 2.
Post job cleanup.
[command]"C:\Program Files\Git\bin\git.exe" version

[bors]

💔 Test failed - checks-actions

[tgross35]

The test crash seems to indicate some kind of ABI mismatch. I am guessing this happens during the libcall to __eqtf2 or __unordtf2, but I am unsure why this would be since we don't do anything special with that ABI https://github.com/rust-lang/compiler-builtins/blob/f1b9055b0d09370a474ce5e9b9d78ac4758cedf8/compiler-builtins/src/float/cmp.rs#L181-L189.

[beetrees]

Only LLVM 21+ uses the new indirect ABI; Rust currently ships with LLVM 20 which will use the old ABI when generating calls to functions in compiler-builtins.