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compiler: simplify TargetOptions ABI functions

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`adjust_abi` is not needed and `is_abi_supported` can be a 1-liner.
This commit is contained in:
Jubilee Young 2025-05-25 20:40:18 -07:00
parent 2ad64b4c17
commit 2351a3e5b4
2 changed files with 2 additions and 108 deletions
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1
compiler/rustc_target/src/callconv/mod.rs
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@ -697,7 +697,6 @@ impl<'a, Ty> FnAbi<'a, Ty> {
"sparc" => sparc::compute_abi_info(cx, self),
"sparc64" => sparc64::compute_abi_info(cx, self),
"nvptx64" => {
let abi = cx.target_spec().adjust_abi(abi, self.c_variadic);
if abi == ExternAbi::PtxKernel || abi == ExternAbi::GpuKernel {
nvptx64::compute_ptx_kernel_abi_info(cx, self)
} else {

109
compiler/rustc_target/src/spec/mod.rs
View File

@ -2915,114 +2915,9 @@ impl DerefMut for Target {
}
impl Target {
/// Given a function ABI, turn it into the correct ABI for this target.
pub fn adjust_abi(&self, abi: ExternAbi, c_variadic: bool) -> ExternAbi {
use ExternAbi::*;
match abi {
// On Windows, `extern "system"` behaves like msvc's `__stdcall`.
// `__stdcall` only applies on x86 and on non-variadic functions:
// https://learn.microsoft.com/en-us/cpp/cpp/stdcall?view=msvc-170
System { unwind } => {
if self.is_like_windows && self.arch == "x86" && !c_variadic {
Stdcall { unwind }
} else {
C { unwind }
}
}
EfiApi => {
if self.arch == "arm" {
Aapcs { unwind: false }
} else if self.arch == "x86_64" {
Win64 { unwind: false }
} else {
C { unwind: false }
}
}
// See commentary in `is_abi_supported`.
Stdcall { unwind } | Thiscall { unwind } | Fastcall { unwind } => {
if self.arch == "x86" { abi } else { C { unwind } }
}
Vectorcall { unwind } => {
if ["x86", "x86_64"].contains(&&*self.arch) {
abi
} else {
C { unwind }
}
}
// The Windows x64 calling convention we use for `extern "Rust"`
// <https://learn.microsoft.com/en-us/cpp/build/x64-software-conventions#register-volatility-and-preservation>
// expects the callee to save `xmm6` through `xmm15`, but `PreserveMost`
// (that we use by default for `extern "rust-cold"`) doesn't save any of those.
// So to avoid bloating callers, just use the Rust convention here.
RustCold if self.is_like_windows && self.arch == "x86_64" => Rust,
abi => abi,
}
}
pub fn is_abi_supported(&self, abi: ExternAbi) -> bool {
use ExternAbi::*;
match abi {
Rust | C { .. } | System { .. } | RustCall | Unadjusted | Cdecl { .. } | RustCold => {
true
}
EfiApi => {
["arm", "aarch64", "riscv32", "riscv64", "x86", "x86_64"].contains(&&self.arch[..])
}
X86Interrupt => ["x86", "x86_64"].contains(&&self.arch[..]),
Aapcs { .. } => "arm" == self.arch,
CCmseNonSecureCall | CCmseNonSecureEntry => {
["thumbv8m.main-none-eabi", "thumbv8m.main-none-eabihf", "thumbv8m.base-none-eabi"]
.contains(&&self.llvm_target[..])
}
Win64 { .. } | SysV64 { .. } => self.arch == "x86_64",
PtxKernel => self.arch == "nvptx64",
GpuKernel => ["amdgpu", "nvptx64"].contains(&&self.arch[..]),
Msp430Interrupt => self.arch == "msp430",
RiscvInterruptM | RiscvInterruptS => ["riscv32", "riscv64"].contains(&&self.arch[..]),
AvrInterrupt | AvrNonBlockingInterrupt => self.arch == "avr",
Thiscall { .. } => self.arch == "x86",
// On windows these fall-back to platform native calling convention (C) when the
// architecture is not supported.
//
// This is I believe a historical accident that has occurred as part of Microsoft
// striving to allow most of the code to "just" compile when support for 64-bit x86
// was added and then later again, when support for ARM architectures was added.
//
// This is well documented across MSDN. Support for this in Rust has been added in
// #54576. This makes much more sense in context of Microsoft's C++ than it does in
// Rust, but there isn't much leeway remaining here to change it back at the time this
// comment has been written.
//
// Following are the relevant excerpts from the MSDN documentation.
//
// > The __vectorcall calling convention is only supported in native code on x86 and
// x64 processors that include Streaming SIMD Extensions 2 (SSE2) and above.
// > ...
// > On ARM machines, __vectorcall is accepted and ignored by the compiler.
//
// -- https://docs.microsoft.com/en-us/cpp/cpp/vectorcall?view=msvc-160
//
// > On ARM and x64 processors, __stdcall is accepted and ignored by the compiler;
//
// -- https://docs.microsoft.com/en-us/cpp/cpp/stdcall?view=msvc-160
//
// > In most cases, keywords or compiler switches that specify an unsupported
// > convention on a particular platform are ignored, and the platform default
// > convention is used.
//
// -- https://docs.microsoft.com/en-us/cpp/cpp/argument-passing-and-naming-conventions
Stdcall { .. } | Fastcall { .. } | Vectorcall { .. } if self.is_like_windows => true,
// Outside of Windows we want to only support these calling conventions for the
// architectures for which these calling conventions are actually well defined.
Stdcall { .. } | Fastcall { .. } if self.arch == "x86" => true,
Vectorcall { .. } if ["x86", "x86_64"].contains(&&self.arch[..]) => true,
// Reject these calling conventions everywhere else.
Stdcall { .. } | Fastcall { .. } | Vectorcall { .. } => false,
}
let abi_map = AbiMap::from_target(self);
abi_map.canonize_abi(abi, false).is_mapped()
}
/// Minimum integer size in bits that this target can perform atomic