Auto merge of #97369 - tmiasko:codgen-ssa-atomic-ordering, r=michaelwoerister

rustc_codegen_ssa: cleanup `AtomicOrdering`

* Remove unused `NotAtomic` ordering.
* Rename `Monotonic` to `Relaxed` - a Rust specific name.
* Derive copy and clone.

Author: bors

compiler/rustc_codegen_gcc/src/builder.rs

@@ -61,24 +61,6 @@ enum ExtremumOperation {
     Min,
 }
 
-trait EnumClone {
-    fn clone(&self) -> Self;
-}
-
-impl EnumClone for AtomicOrdering {
-    fn clone(&self) -> Self {
-        match *self {
-            AtomicOrdering::NotAtomic => AtomicOrdering::NotAtomic,
-            AtomicOrdering::Unordered => AtomicOrdering::Unordered,
-            AtomicOrdering::Monotonic => AtomicOrdering::Monotonic,
-            AtomicOrdering::Acquire => AtomicOrdering::Acquire,
-            AtomicOrdering::Release => AtomicOrdering::Release,
-            AtomicOrdering::AcquireRelease => AtomicOrdering::AcquireRelease,
-            AtomicOrdering::SequentiallyConsistent => AtomicOrdering::SequentiallyConsistent,
-        }
-    }
-}
-
 pub struct Builder<'a: 'gcc, 'gcc, 'tcx> {
     pub cx: &'a CodegenCx<'gcc, 'tcx>,
     pub block: Block<'gcc>,
@@ -103,9 +85,9 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             match order {
                 // TODO(antoyo): does this make sense?
                 AtomicOrdering::AcquireRelease | AtomicOrdering::Release => AtomicOrdering::Acquire,
-                _ => order.clone(),
+                _ => order,
             };
-        let previous_value = self.atomic_load(dst.get_type(), dst, load_ordering.clone(), Size::from_bytes(size));
+        let previous_value = self.atomic_load(dst.get_type(), dst, load_ordering, Size::from_bytes(size));
         let previous_var = func.new_local(None, previous_value.get_type(), "previous_value");
         let return_value = func.new_local(None, previous_value.get_type(), "return_value");
         self.llbb().add_assignment(None, previous_var, previous_value);
@@ -1384,9 +1366,8 @@ impl ToGccOrdering for AtomicOrdering {
 
         let ordering =
             match self {
-                AtomicOrdering::NotAtomic => __ATOMIC_RELAXED, // TODO(antoyo): check if that's the same.
                 AtomicOrdering::Unordered => __ATOMIC_RELAXED,
-                AtomicOrdering::Monotonic => __ATOMIC_RELAXED, // TODO(antoyo): check if that's the same.
+                AtomicOrdering::Relaxed => __ATOMIC_RELAXED, // TODO(antoyo): check if that's the same.
                 AtomicOrdering::Acquire => __ATOMIC_ACQUIRE,
                 AtomicOrdering::Release => __ATOMIC_RELEASE,
                 AtomicOrdering::AcquireRelease => __ATOMIC_ACQ_REL,

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -381,9 +381,8 @@ pub enum AtomicOrdering {
 impl AtomicOrdering {
     pub fn from_generic(ao: rustc_codegen_ssa::common::AtomicOrdering) -> Self {
         match ao {
-            rustc_codegen_ssa::common::AtomicOrdering::NotAtomic => AtomicOrdering::NotAtomic,
             rustc_codegen_ssa::common::AtomicOrdering::Unordered => AtomicOrdering::Unordered,
-            rustc_codegen_ssa::common::AtomicOrdering::Monotonic => AtomicOrdering::Monotonic,
+            rustc_codegen_ssa::common::AtomicOrdering::Relaxed => AtomicOrdering::Monotonic,
             rustc_codegen_ssa::common::AtomicOrdering::Acquire => AtomicOrdering::Acquire,
             rustc_codegen_ssa::common::AtomicOrdering::Release => AtomicOrdering::Release,
             rustc_codegen_ssa::common::AtomicOrdering::AcquireRelease => {

compiler/rustc_codegen_ssa/src/common.rs

@@ -11,6 +11,7 @@ use rustc_span::Span;
 use crate::base;
 use crate::traits::*;
 
+#[derive(Copy, Clone)]
 pub enum IntPredicate {
     IntEQ,
     IntNE,
@@ -24,6 +25,7 @@ pub enum IntPredicate {
     IntSLE,
 }
 
+#[derive(Copy, Clone)]
 pub enum RealPredicate {
     RealPredicateFalse,
     RealOEQ,
@@ -43,6 +45,7 @@ pub enum RealPredicate {
     RealPredicateTrue,
 }
 
+#[derive(Copy, Clone)]
 pub enum AtomicRmwBinOp {
     AtomicXchg,
     AtomicAdd,
@@ -57,17 +60,17 @@ pub enum AtomicRmwBinOp {
     AtomicUMin,
 }
 
+#[derive(Copy, Clone)]
 pub enum AtomicOrdering {
-    NotAtomic,
     Unordered,
-    Monotonic,
-    // Consume,  // Not specified yet.
+    Relaxed,
     Acquire,
     Release,
     AcquireRelease,
     SequentiallyConsistent,
 }
 
+#[derive(Copy, Clone)]
 pub enum SynchronizationScope {
     SingleThread,
     CrossThread,

compiler/rustc_codegen_ssa/src/mir/intrinsic.rs

@@ -388,17 +388,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     2 => (SequentiallyConsistent, SequentiallyConsistent),
                     3 => match split[2] {
                         "unordered" => (Unordered, Unordered),
-                        "relaxed" => (Monotonic, Monotonic),
+                        "relaxed" => (Relaxed, Relaxed),
                         "acq" => (Acquire, Acquire),
-                        "rel" => (Release, Monotonic),
+                        "rel" => (Release, Relaxed),
                         "acqrel" => (AcquireRelease, Acquire),
-                        "failrelaxed" if is_cxchg => (SequentiallyConsistent, Monotonic),
+                        "failrelaxed" if is_cxchg => (SequentiallyConsistent, Relaxed),
                         "failacq" if is_cxchg => (SequentiallyConsistent, Acquire),
                         _ => bx.sess().fatal("unknown ordering in atomic intrinsic"),
                     },
                     4 => match (split[2], split[3]) {
-                        ("acq", "failrelaxed") if is_cxchg => (Acquire, Monotonic),
-                        ("acqrel", "failrelaxed") if is_cxchg => (AcquireRelease, Monotonic),
+                        ("acq", "failrelaxed") if is_cxchg => (Acquire, Relaxed),
+                        ("acqrel", "failrelaxed") if is_cxchg => (AcquireRelease, Relaxed),
                         _ => bx.sess().fatal("unknown ordering in atomic intrinsic"),
                     },
                     _ => bx.sess().fatal("Atomic intrinsic not in correct format"),