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Add element-wise atomic memory operations #59155

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27 changes: 27 additions & 0 deletions src/libcore/intrinsics.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -962,6 +962,33 @@ extern "rust-intrinsic" {
/// value is not necessarily valid to be used to actually access memory.
pub fn arith_offset<T>(dst: *const T, offset: isize) -> *const T;

/// Equivalent to the appropriate `llvm.memcpy.element.unordered.atomic.p0i8.p0i8.*` intrinsic, with
/// a size of `count` * `size_of::<T>()`, an alignment of
/// `min_align_of::<T>()`, and an element size of `size_of::<T>()`.
///
/// `size_of::<T>` must be an integer power of two no larger than the
/// target-specific atomic access size limit.
#[cfg(not(stage0))]
pub fn atomic_element_copy_nonoverlapping_memory_unordered<T>(dst: *mut T, src: *const T, count: usize);

/// Equivalent to the appropriate `llvm.memmove.unordered.atomic.p0i8.p0i8.*` intrinsic, with
/// a size of `count` * `size_of::<T>()`, an alignment of
/// `min_align_of::<T>()`, and an element size of `size_of::<T>()`.
///
/// `size_of::<T>` must be an integer power of two no larger than the
/// target-specific atomic access size limit.
#[cfg(not(stage0))]
pub fn atomic_element_copy_memory_unordered<T>(dst: *mut T, src: *const T, count: usize);

/// Equivalent to the appropriate `llvm.memset.unordered.atomic.p0i8.p0i8.*` intrinsic, with
/// a size of `count` * `size_of::<T>()`, an alignment of
/// `min_align_of::<T>()`, and an element size of `size_of::<T>()`.
///
/// `size_of::<T>` must be an integer power of two no larger than the
/// target-specific atomic access size limit.
#[cfg(not(stage0))]
pub fn atomic_element_set_memory_unordered<T>(dst: *mut T, val: u8, count: usize);

/// Equivalent to the appropriate `llvm.memcpy.p0i8.0i8.*` intrinsic, with
/// a size of `count` * `size_of::<T>()` and an alignment of
/// `min_align_of::<T>()`
Expand Down
42 changes: 42 additions & 0 deletions src/librustc_codegen_llvm/builder.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -966,6 +966,48 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
self.call(llintrinsicfn, &[ptr, fill_byte, size, align, volatile], None);
}

fn atomic_element_unordered_memcpy(&mut self, dst: &'ll Value, dst_align: Align,
src: &'ll Value, src_align: Align,
size: &'ll Value, element_size: u32) {
let size = self.intcast(size, self.type_isize(), false);
let dst = self.pointercast(dst, self.type_i8p());
let src = self.pointercast(src, self.type_i8p());
unsafe {
llvm::LLVMRustBuildElementUnorderedAtomicMemCpy(self.llbuilder, dst, dst_align.bytes() as c_uint,
src, src_align.bytes() as c_uint, size, element_size);
}
}

fn atomic_element_unordered_memmove(&mut self, dst: &'ll Value, dst_align: Align,
src: &'ll Value, src_align: Align,
size: &'ll Value, element_size: u32) {
let size = self.intcast(size, self.type_isize(), false);
let dst = self.pointercast(dst, self.type_i8p());
let src = self.pointercast(src, self.type_i8p());
let ret_ref = unsafe {
llvm::LLVMRustBuildElementUnorderedAtomicMemMove(self.llbuilder,
dst, dst_align.bytes() as c_uint,
src, src_align.bytes() as c_uint,
size, element_size)
};
if ret_ref.is_none() {
bug!("llvm.memmove.element.unordered.atomic.* is not supported with LLVM prior to 7.0");
}
}

fn atomic_element_unordered_memset(&mut self, ptr: &'ll Value, fill_byte: &'ll Value,
size: &'ll Value, align: Align, element_size: u32) {
let size = self.intcast(size, self.type_isize(), false);
let ptr = self.pointercast(ptr, self.type_i8p());
let ret_ref = unsafe {
llvm::LLVMRustBuildElementUnorderedAtomicMemSet(self.llbuilder, ptr, fill_byte,
size, align.bytes() as c_uint, element_size)
};
if ret_ref.is_none() {
bug!("llvm.memset.element.unordered.atomic.* is not supported with LLVM prior to 7.0");
}
}

fn select(
&mut self, cond: &'ll Value,
then_val: &'ll Value,
Expand Down
86 changes: 72 additions & 14 deletions src/librustc_codegen_llvm/intrinsic.rs
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Expand Up @@ -102,6 +102,13 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
let llret_ty = self.layout_of(ret_ty).llvm_type(self);
let result = PlaceRef::new_sized(llresult, fn_ty.ret.layout, fn_ty.ret.layout.align.abi);

let invalid_integer_monomorphization = |ty| {
span_invalid_monomorphization_error(tcx.sess, span,
&format!("invalid monomorphization of `{}` intrinsic: \
expected basic integer type, found `{}`", name, ty));
};


let simple = get_simple_intrinsic(self, name);
let llval = match name {
_ if simple.is_some() => {
Expand Down Expand Up @@ -503,10 +510,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
_ => bug!(),
},
None => {
span_invalid_monomorphization_error(
tcx.sess, span,
&format!("invalid monomorphization of `{}` intrinsic: \
expected basic integer type, found `{}`", name, ty));
invalid_integer_monomorphization(ty);
return;
}
}
Expand Down Expand Up @@ -548,6 +552,17 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
Err(()) => return
}
}
name if name.starts_with("atomic_element_") => {
let ty = substs.type_at(0);
if int_type_width_signed(ty, self).is_some() {
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This restricts the type to integer types. I'm not sure if this is the best action, or if we should accept any type with a size that is a power of two less than the target-specific atomic size limit. But this is what we do for other atomic operations, so it is my first inclination.

atomic_element_intrinsic(self, name,
substs.type_at(0),
args);
return;
} else {
return invalid_integer_monomorphization(ty);
}
}
// This requires that atomic intrinsics follow a specific naming pattern:
// "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
name if name.starts_with("atomic_") => {
Expand Down Expand Up @@ -582,12 +597,6 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
_ => self.sess().fatal("Atomic intrinsic not in correct format"),
};

let invalid_monomorphization = |ty| {
span_invalid_monomorphization_error(tcx.sess, span,
&format!("invalid monomorphization of `{}` intrinsic: \
expected basic integer type, found `{}`", name, ty));
};

match split[1] {
"cxchg" | "cxchgweak" => {
let ty = substs.type_at(0);
Expand All @@ -610,7 +619,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
self.store(success, dest.llval, dest.align);
return;
} else {
return invalid_monomorphization(ty);
return invalid_integer_monomorphization(ty);
}
}

Expand All @@ -620,7 +629,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
let size = self.size_of(ty);
self.atomic_load(args[0].immediate(), order, size)
} else {
return invalid_monomorphization(ty);
return invalid_integer_monomorphization(ty);
}
}

Expand All @@ -636,7 +645,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
);
return;
} else {
return invalid_monomorphization(ty);
return invalid_integer_monomorphization(ty);
}
}

Expand Down Expand Up @@ -676,7 +685,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
order
)
} else {
return invalid_monomorphization(ty);
return invalid_integer_monomorphization(ty);
}
}
}
Expand Down Expand Up @@ -754,6 +763,54 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
}
}

fn atomic_element_intrinsic(
bx: &mut Builder<'a, 'll, 'tcx>,
name: &str,
ty: Ty<'tcx>,
args: &[OperandRef<'tcx, &'ll Value>],
) {
let (element_size, align) = bx.size_and_align_of(ty);
let element_size = element_size.bytes();
assert!(element_size <= u32::max_value() as u64);

let size = bx.mul(bx.const_usize(element_size), args[2].immediate());

match name {
"atomic_element_copy_nonoverlapping_memory_unordered" => {
bx.atomic_element_unordered_memcpy(
args[0].immediate(),
align,
args[1].immediate(),
align,
size,
element_size as u32
);
}
"atomic_element_copy_memory_unordered" => {
bx.atomic_element_unordered_memmove(
args[0].immediate(),
align,
args[1].immediate(),
align,
size,
element_size as u32
);
}
"atomic_element_set_memory_unordered" => {
bx.atomic_element_unordered_memset(
args[0].immediate(),
args[1].immediate(),
size,
align,
element_size as u32
);
}
_ => {
bug!("unknown intrinsic '{}'", name);
}
}
}

fn copy_intrinsic(
bx: &mut Builder<'a, 'll, 'tcx>,
allow_overlap: bool,
Expand All @@ -777,6 +834,7 @@ fn copy_intrinsic(
}
}


fn memset_intrinsic(
bx: &mut Builder<'a, 'll, 'tcx>,
volatile: bool,
Expand Down
22 changes: 22 additions & 0 deletions src/librustc_codegen_llvm/llvm/ffi.rs
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Expand Up @@ -1154,6 +1154,28 @@ extern "C" {
Size: &'a Value,
IsVolatile: bool)
-> &'a Value;
pub fn LLVMRustBuildElementUnorderedAtomicMemCpy(B: &Builder<'a>,
Dst: &'a Value,
DstAlign: c_uint,
Src: &'a Value,
SrcAlign: c_uint,
Size: &'a Value,
ElementSize: u32)
-> &'a Value;
pub fn LLVMRustBuildElementUnorderedAtomicMemMove(B: &Builder<'a>,
Dst: &'a Value,
DstAlign: c_uint,
Src: &'a Value,
SrcAlign: c_uint,
Size: &'a Value,
ElementSize: u32) -> Option<&'a Value>;
pub fn LLVMRustBuildElementUnorderedAtomicMemSet(B: &Builder<'a>,
Ptr: &'a Value,
Val: &'a Value,
Size: &'a Value,
Align: c_uint,
ElementSize: u32) -> Option<&'a Value>;

pub fn LLVMRustBuildMemMove(B: &Builder<'a>,
Dst: &'a Value,
DstAlign: c_uint,
Expand Down
27 changes: 27 additions & 0 deletions src/librustc_codegen_ssa/traits/builder.rs
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Expand Up @@ -190,6 +190,33 @@ pub trait BuilderMethods<'a, 'tcx: 'a>:
flags: MemFlags,
);

fn atomic_element_unordered_memcpy(
&mut self,
dst: Self::Value,
dst_align: Align,
src: Self::Value,
src_align: Align,
size: Self::Value,
element_size: u32,
);
fn atomic_element_unordered_memmove(
&mut self,
dst: Self::Value,
dst_align: Align,
src: Self::Value,
src_align: Align,
size: Self::Value,
element_size: u32,
);
fn atomic_element_unordered_memset(
&mut self,
ptr: Self::Value,
fill_byte: Self::Value,
size: Self::Value,
align: Align,
element_size: u32,
);

fn select(
&mut self,
cond: Self::Value,
Expand Down
7 changes: 4 additions & 3 deletions src/librustc_typeck/check/intrinsic.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -92,7 +92,7 @@ pub fn check_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
})
};

let (n_tps, inputs, output, unsafety) = if name.starts_with("atomic_") {
let (n_tps, inputs, output, unsafety) = if name.starts_with("atomic_") && ! name.starts_with("atomic_element_") {
let split : Vec<&str> = name.split('_').collect();
assert!(split.len() >= 2, "Atomic intrinsic in an incorrect format");

Expand Down Expand Up @@ -197,7 +197,8 @@ pub fn check_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
],
tcx.mk_unit())
}
"volatile_copy_memory" | "volatile_copy_nonoverlapping_memory" => {
"volatile_copy_memory" | "volatile_copy_nonoverlapping_memory" |
"atomic_element_copy_memory_unordered" | "atomic_element_copy_nonoverlapping_memory_unordered" => {
(1,
vec![
tcx.mk_ptr(ty::TypeAndMut {
Expand All @@ -212,7 +213,7 @@ pub fn check_intrinsic_type<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
],
tcx.mk_unit())
}
"write_bytes" | "volatile_set_memory" => {
"write_bytes" | "volatile_set_memory" | "atomic_element_set_memory_unordered" => {
(1,
vec![
tcx.mk_ptr(ty::TypeAndMut {
Expand Down
36 changes: 36 additions & 0 deletions src/rustllvm/RustWrapper.cpp
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Expand Up @@ -1268,6 +1268,42 @@ extern "C" LLVMValueRef LLVMRustBuildMemMove(LLVMBuilderRef B,
#endif
}

extern "C" LLVMValueRef LLVMRustBuildElementUnorderedAtomicMemCpy(LLVMBuilderRef B,
LLVMValueRef Dst, unsigned DstAlign,
LLVMValueRef Src, unsigned SrcAlign,
LLVMValueRef Size, uint32_t ElementSize) {
return wrap(unwrap(B)->CreateElementUnorderedAtomicMemCpy(
unwrap(Dst), DstAlign,
unwrap(Src), SrcAlign,
unwrap(Size), ElementSize));
}

extern "C" LLVMValueRef LLVMRustBuildElementUnorderedAtomicMemMove(LLVMBuilderRef B,
LLVMValueRef Dst, unsigned DstAlign,
LLVMValueRef Src, unsigned SrcAlign,
LLVMValueRef Size, uint32_t ElementSize) {
#if LLVM_VERSION_GE(7, 0)
return wrap(unwrap(B)->CreateElementUnorderedAtomicMemMove(
unwrap(Dst), DstAlign,
unwrap(Src), SrcAlign,
unwrap(Size), ElementSize));
#else
return nullptr;
#endif
}

extern "C" LLVMValueRef LLVMRustBuildElementUnorderedAtomicMemSet(LLVMBuilderRef B,
LLVMValueRef Ptr, LLVMValueRef Val,
LLVMValueRef Size, unsigned Align, uint32_t ElementSize) {
#if LLVM_VERSION_GE(7, 0)
return wrap(unwrap(B)->CreateElementUnorderedAtomicMemSet(
unwrap(Ptr), unwrap(Val),
unwrap(Size), Align, ElementSize));
#else
return nullptr;
#endif
}

extern "C" LLVMValueRef
LLVMRustBuildInvoke(LLVMBuilderRef B, LLVMValueRef Fn, LLVMValueRef *Args,
unsigned NumArgs, LLVMBasicBlockRef Then,
Expand Down
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