From 69b5a9f2eb8b7d16091b76a2a5b84cd4889eefe2 Mon Sep 17 00:00:00 2001 From: Bernd Schmidt Date: Thu, 30 Nov 2023 14:54:27 +0100 Subject: [PATCH] Change `rustc_codegen_ssa`'s `atomic_cmpxchg` interface to return a pair of values --- src/builder.rs | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/src/builder.rs b/src/builder.rs index b8a8c144dc9..42e61b3ccb5 100644 --- a/src/builder.rs +++ b/src/builder.rs @@ -1296,7 +1296,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { } // Atomic Operations - fn atomic_cmpxchg(&mut self, dst: RValue<'gcc>, cmp: RValue<'gcc>, src: RValue<'gcc>, order: AtomicOrdering, failure_order: AtomicOrdering, weak: bool) -> RValue<'gcc> { + fn atomic_cmpxchg(&mut self, dst: RValue<'gcc>, cmp: RValue<'gcc>, src: RValue<'gcc>, order: AtomicOrdering, failure_order: AtomicOrdering, weak: bool) -> (RValue<'gcc>, RValue<'gcc>) { let expected = self.current_func().new_local(None, cmp.get_type(), "expected"); self.llbb().add_assignment(None, expected, cmp); // NOTE: gcc doesn't support a failure memory model that is stronger than the success @@ -1310,20 +1310,12 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { }; let success = self.compare_exchange(dst, expected, src, order, failure_order, weak); - let pair_type = self.cx.type_struct(&[src.get_type(), self.bool_type], false); - let result = self.current_func().new_local(None, pair_type, "atomic_cmpxchg_result"); - let align = Align::from_bits(64).expect("align"); // TODO(antoyo): use good align. + // NOTE: since success contains the call to the intrinsic, it must be added to the basic block before + // expected so that we store expected after the call. + let success_var = self.current_func().new_local(None, self.bool_type, "success"); + self.llbb().add_assignment(None, success_var, success); - let value_type = result.to_rvalue().get_type(); - if let Some(struct_type) = value_type.is_struct() { - self.store(success, result.access_field(None, struct_type.get_field(1)).get_address(None), align); - // NOTE: since success contains the call to the intrinsic, it must be stored before - // expected so that we store expected after the call. - self.store(expected.to_rvalue(), result.access_field(None, struct_type.get_field(0)).get_address(None), align); - } - // TODO(antoyo): handle when value is not a struct. - - result.to_rvalue() + (expected.to_rvalue(), success_var.to_rvalue()) } fn atomic_rmw(&mut self, op: AtomicRmwBinOp, dst: RValue<'gcc>, src: RValue<'gcc>, order: AtomicOrdering) -> RValue<'gcc> {