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Auto merge of #76295 - mati865:remove-mmx, r=Amanieu,oli-obk

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Remove MMX from Rust

Follow-up to https://github.com/rust-lang/stdarch/pull/890
This removes most of MMX from Rust (tests pass with small changes), keeping stable `is_x86_feature_detected!("mmx")` working.
This commit is contained in:
bors 2020-09-21 00:43:26 +00:00
commit 0f9f0b384a
12 changed files with 6 additions and 60 deletions
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1
compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View file

@ -948,7 +948,6 @@ extern "C" {
// Operations on other types
pub fn LLVMVoidTypeInContext(C: &Context) -> &Type;
pub fn LLVMX86MMXTypeInContext(C: &Context) -> &Type;
pub fn LLVMRustMetadataTypeInContext(C: &Context) -> &Type;
// Operations on all values

1
compiler/rustc_codegen_llvm/src/llvm_util.rs
View file

@ -203,7 +203,6 @@ const X86_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
("fma", None),
("fxsr", None),
("lzcnt", None),
("mmx", Some(sym::mmx_target_feature)),
("movbe", Some(sym::movbe_target_feature)),
("pclmulqdq", None),
("popcnt", None),

4
compiler/rustc_codegen_llvm/src/type_.rs
View file

@ -62,10 +62,6 @@ impl CodegenCx<'ll, 'tcx> {
unsafe { llvm::LLVMIntTypeInContext(self.llcx, num_bits as c_uint) }
}
crate fn type_x86_mmx(&self) -> &'ll Type {
unsafe { llvm::LLVMX86MMXTypeInContext(self.llcx) }
}
crate fn type_vector(&self, ty: &'ll Type, len: u64) -> &'ll Type {
unsafe { llvm::LLVMVectorType(ty, len as c_uint) }
}

19
compiler/rustc_codegen_llvm/src/type_of.rs
View file

@ -21,23 +21,8 @@ fn uncached_llvm_type<'a, 'tcx>(
match layout.abi {
Abi::Scalar(_) => bug!("handled elsewhere"),
Abi::Vector { ref element, count } => {
// LLVM has a separate type for 64-bit SIMD vectors on X86 called
// `x86_mmx` which is needed for some SIMD operations. As a bit of a
// hack (all SIMD definitions are super unstable anyway) we
// recognize any one-element SIMD vector as "this should be an
// x86_mmx" type. In general there shouldn't be a need for other
// one-element SIMD vectors, so it's assumed this won't clash with
// much else.
let use_x86_mmx = count == 1
&& layout.size.bits() == 64
&& (cx.sess().target.target.arch == "x86"
|| cx.sess().target.target.arch == "x86_64");
if use_x86_mmx {
return cx.type_x86_mmx();
} else {
let element = layout.scalar_llvm_type_at(cx, element, Size::ZERO);
return cx.type_vector(element, count);
}
let element = layout.scalar_llvm_type_at(cx, element, Size::ZERO);
return cx.type_vector(element, count);
}
Abi::ScalarPair(..) => {
return cx.type_struct(