Rollup merge of #144192 - RalfJung:atomicrmw-ptr, r=nikic

atomicrmw on pointers: move integer-pointer cast hacks into backend

Conceptually, we want to have atomic operations on pointers of the form `fn atomic_add(ptr: *mut T, offset: usize, ...)`. However, LLVM does not directly support such operations (https://github.com/llvm/llvm-project/issues/120837), so we have to cast the `offset` to a pointer somewhere.

This PR moves that hack into the LLVM backend, so that the standard library, intrinsic, and Miri all work with the conceptual operation we actually want. Hopefully, one day LLVM will gain a way to represent these operations without integer-pointer casts, and then the hack will disappear entirely.

Cc ```@nikic``` -- this is the best we can do right now, right?
Fixes https://github.com/rust-lang/rust/issues/134617

1 files changed, 12 insertions, 12 deletions

diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
index 4ff5773a06c..ed40901ac9b 100644
--- a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
@@ -969,7 +969,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let layout = amount.layout();
             match layout.ty.kind() {
-                ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
+                ty::Uint(_) | ty::Int(_) => {}
                 _ => {
                     report_atomic_type_validation_error(fx, intrinsic, source_info.span, layout.ty);
                     return Ok(());
@@ -982,7 +982,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
             let old =
                 fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Add, ptr, amount);
 
-            let old = CValue::by_val(old, layout);
+            let old = CValue::by_val(old, ret.layout());
             ret.write_cvalue(fx, old);
         }
         sym::atomic_xsub => {
@@ -991,7 +991,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let layout = amount.layout();
             match layout.ty.kind() {
-                ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
+                ty::Uint(_) | ty::Int(_) => {}
                 _ => {
                     report_atomic_type_validation_error(fx, intrinsic, source_info.span, layout.ty);
                     return Ok(());
@@ -1004,7 +1004,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
             let old =
                 fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Sub, ptr, amount);
 
-            let old = CValue::by_val(old, layout);
+            let old = CValue::by_val(old, ret.layout());
             ret.write_cvalue(fx, old);
         }
         sym::atomic_and => {
@@ -1013,7 +1013,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let layout = src.layout();
             match layout.ty.kind() {
-                ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
+                ty::Uint(_) | ty::Int(_) => {}
                 _ => {
                     report_atomic_type_validation_error(fx, intrinsic, source_info.span, layout.ty);
                     return Ok(());
@@ -1025,7 +1025,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::And, ptr, src);
 
-            let old = CValue::by_val(old, layout);
+            let old = CValue::by_val(old, ret.layout());
             ret.write_cvalue(fx, old);
         }
         sym::atomic_or => {
@@ -1034,7 +1034,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let layout = src.layout();
             match layout.ty.kind() {
-                ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
+                ty::Uint(_) | ty::Int(_) => {}
                 _ => {
                     report_atomic_type_validation_error(fx, intrinsic, source_info.span, layout.ty);
                     return Ok(());
@@ -1046,7 +1046,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Or, ptr, src);
 
-            let old = CValue::by_val(old, layout);
+            let old = CValue::by_val(old, ret.layout());
             ret.write_cvalue(fx, old);
         }
         sym::atomic_xor => {
@@ -1055,7 +1055,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let layout = src.layout();
             match layout.ty.kind() {
-                ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
+                ty::Uint(_) | ty::Int(_) => {}
                 _ => {
                     report_atomic_type_validation_error(fx, intrinsic, source_info.span, layout.ty);
                     return Ok(());
@@ -1067,7 +1067,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Xor, ptr, src);
 
-            let old = CValue::by_val(old, layout);
+            let old = CValue::by_val(old, ret.layout());
             ret.write_cvalue(fx, old);
         }
         sym::atomic_nand => {
@@ -1076,7 +1076,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let layout = src.layout();
             match layout.ty.kind() {
-                ty::Uint(_) | ty::Int(_) | ty::RawPtr(..) => {}
+                ty::Uint(_) | ty::Int(_) => {}
                 _ => {
                     report_atomic_type_validation_error(fx, intrinsic, source_info.span, layout.ty);
                     return Ok(());
@@ -1088,7 +1088,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
 
             let old = fx.bcx.ins().atomic_rmw(ty, MemFlags::trusted(), AtomicRmwOp::Nand, ptr, src);
 
-            let old = CValue::by_val(old, layout);
+            let old = CValue::by_val(old, ret.layout());
             ret.write_cvalue(fx, old);
         }
         sym::atomic_max => {