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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-07 05:48:48 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-07 05:48:48 +0000
commitef24de24a82fe681581cc130f342363c47c0969a (patch)
tree0d494f7e1a38b95c92426f58fe6eaa877303a86c /compiler/rustc_target/src/spec/i686_unknown_uefi.rs
parentReleasing progress-linux version 1.74.1+dfsg1-1~progress7.99u1. (diff)
downloadrustc-ef24de24a82fe681581cc130f342363c47c0969a.tar.xz
rustc-ef24de24a82fe681581cc130f342363c47c0969a.zip
Merging upstream version 1.75.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_target/src/spec/i686_unknown_uefi.rs')
-rw-r--r--compiler/rustc_target/src/spec/i686_unknown_uefi.rs89
1 files changed, 0 insertions, 89 deletions
diff --git a/compiler/rustc_target/src/spec/i686_unknown_uefi.rs b/compiler/rustc_target/src/spec/i686_unknown_uefi.rs
deleted file mode 100644
index a2e42c5e6..000000000
--- a/compiler/rustc_target/src/spec/i686_unknown_uefi.rs
+++ /dev/null
@@ -1,89 +0,0 @@
-// This defines the ia32 target for UEFI systems as described in the UEFI specification. See the
-// uefi-base module for generic UEFI options. On ia32 systems
-// UEFI systems always run in protected-mode, have the interrupt-controller pre-configured and
-// force a single-CPU execution.
-// The cdecl ABI is used. It differs from the stdcall or fastcall ABI.
-// "i686-unknown-windows" is used to get the minimal subset of windows-specific features.
-
-use crate::spec::Target;
-
-pub fn target() -> Target {
- let mut base = super::uefi_msvc_base::opts();
- base.cpu = "pentium4".into();
- base.max_atomic_width = Some(64);
-
- // We disable MMX and SSE for now, even though UEFI allows using them. Problem is, you have to
- // enable these CPU features explicitly before their first use, otherwise their instructions
- // will trigger an exception. Rust does not inject any code that enables AVX/MMX/SSE
- // instruction sets, so this must be done by the firmware. However, existing firmware is known
- // to leave these uninitialized, thus triggering exceptions if we make use of them. Which is
- // why we avoid them and instead use soft-floats. This is also what GRUB and friends did so
- // far.
- // If you initialize FP units yourself, you can override these flags with custom linker
- // arguments, thus giving you access to full MMX/SSE acceleration.
- base.features = "-mmx,-sse,+soft-float".into();
-
- // Use -GNU here, because of the reason below:
- // Background and Problem:
- // If we use i686-unknown-windows, the LLVM IA32 MSVC generates compiler intrinsic
- // _alldiv, _aulldiv, _allrem, _aullrem, _allmul, which will cause undefined symbol.
- // A real issue is __aulldiv() is referred by __udivdi3() - udivmod_inner!(), from
- // https://github.com/rust-lang-nursery/compiler-builtins.
- // As result, rust-lld generates link error finally.
- // Root-cause:
- // In rust\src\llvm-project\llvm\lib\Target\X86\X86ISelLowering.cpp,
- // we have below code to use MSVC intrinsics. It assumes MSVC target
- // will link MSVC library. But that is NOT true in UEFI environment.
- // UEFI does not link any MSVC or GCC standard library.
- // if (Subtarget.isTargetKnownWindowsMSVC() ||
- // Subtarget.isTargetWindowsItanium()) {
- // // Setup Windows compiler runtime calls.
- // setLibcallName(RTLIB::SDIV_I64, "_alldiv");
- // setLibcallName(RTLIB::UDIV_I64, "_aulldiv");
- // setLibcallName(RTLIB::SREM_I64, "_allrem");
- // setLibcallName(RTLIB::UREM_I64, "_aullrem");
- // setLibcallName(RTLIB::MUL_I64, "_allmul");
- // setLibcallCallingConv(RTLIB::SDIV_I64, CallingConv::X86_StdCall);
- // setLibcallCallingConv(RTLIB::UDIV_I64, CallingConv::X86_StdCall);
- // setLibcallCallingConv(RTLIB::SREM_I64, CallingConv::X86_StdCall);
- // setLibcallCallingConv(RTLIB::UREM_I64, CallingConv::X86_StdCall);
- // setLibcallCallingConv(RTLIB::MUL_I64, CallingConv::X86_StdCall);
- // }
- // The compiler intrinsics should be implemented by compiler-builtins.
- // Unfortunately, compiler-builtins has not provided those intrinsics yet. Such as:
- // i386/divdi3.S
- // i386/lshrdi3.S
- // i386/moddi3.S
- // i386/muldi3.S
- // i386/udivdi3.S
- // i386/umoddi3.S
- // Possible solution:
- // 1. Eliminate Intrinsics generation.
- // 1.1 Choose different target to bypass isTargetKnownWindowsMSVC().
- // 1.2 Remove the "Setup Windows compiler runtime calls" in LLVM
- // 2. Implement Intrinsics.
- // We evaluated all options.
- // #2 is hard because we need implement the intrinsics (_aulldiv) generated
- // from the other intrinsics (__udivdi3) implementation with the same
- // functionality (udivmod_inner). If we let _aulldiv() call udivmod_inner!(),
- // then we are in loop. We may have to find another way to implement udivmod_inner!().
- // #1.2 may break the existing usage.
- // #1.1 seems the simplest solution today.
- // The IA32 -gnu calling convention is same as the one defined in UEFI specification.
- // It uses cdecl, EAX/ECX/EDX as volatile register, and EAX/EDX as return value.
- // We also checked the LLVM X86TargetLowering, the differences between -gnu and -msvc
- // is fmodf(f32), longjmp() and TLS. None of them impacts the UEFI code.
- // As a result, we choose -gnu for i686 version before those intrinsics are implemented in
- // compiler-builtins. After compiler-builtins implements all required intrinsics, we may
- // remove -gnu and use the default one.
- Target {
- llvm_target: "i686-unknown-windows-gnu".into(),
- pointer_width: 32,
- data_layout: "e-m:x-p:32:32-p270:32:32-p271:32:32-p272:64:64-\
- i64:64-f80:32-n8:16:32-a:0:32-S32"
- .into(),
- arch: "x86".into(),
-
- options: base,
- }
-}