Remove const_data_from_alloc to make cg_ssa more amenable for cg_clif

oli-obk · oli-obk · commit 84c8bdebb0b7 · 2025-06-30T09:03:39.000Z
diff --git a/compiler/rustc_codegen_gcc/src/common.rs b/compiler/rustc_codegen_gcc/src/common.rs
@@ -1,6 +1,6 @@
 use gccjit::{LValue, RValue, ToRValue, Type};
 use rustc_abi as abi;
-use rustc_abi::{Align, HasDataLayout};
+use rustc_abi::HasDataLayout;
 use rustc_codegen_ssa::traits::{
     BaseTypeCodegenMethods, ConstCodegenMethods, StaticCodegenMethods,
 };
@@ -40,6 +40,22 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         // SIMD builtins require a constant value.
         self.bitcast_if_needed(value, typ)
     }
+
+    pub fn const_data_from_alloc(&self, alloc: ConstAllocation<'_>) -> RValue<'gcc> {
+        // We ignore the alignment for the purpose of deduping RValues
+        // The alignment is not handled / used in any way by `const_alloc_to_gcc`,
+        // so it is OK to overwrite it here.
+        let mut mock_alloc = alloc.inner().clone();
+        mock_alloc.align = rustc_abi::Align::MAX;
+        // Check if the rvalue is already in the cache - if so, just return it directly.
+        if let Some(res) = self.const_cache.borrow().get(&mock_alloc) {
+            return *res;
+        }
+        // Rvalue not in the cache - convert and add it.
+        let res = crate::consts::const_alloc_to_gcc_uncached(self, alloc);
+        self.const_cache.borrow_mut().insert(mock_alloc, res);
+        res
+    }
 }
 
 pub fn bytes_in_context<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, bytes: &[u8]) -> RValue<'gcc> {
@@ -227,22 +243,6 @@ impl<'gcc, 'tcx> ConstCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         None
     }
 
-    fn const_data_from_alloc(&self, alloc: ConstAllocation<'_>) -> Self::Value {
-        // We ignore the alignment for the purpose of deduping RValues
-        // The alignment is not handled / used in any way by `const_alloc_to_gcc`,
-        // so it is OK to overwrite it here.
-        let mut mock_alloc = alloc.inner().clone();
-        mock_alloc.align = rustc_abi::Align::MAX;
-        // Check if the rvalue is already in the cache - if so, just return it directly.
-        if let Some(res) = self.const_cache.borrow().get(&mock_alloc) {
-            return *res;
-        }
-        // Rvalue not in the cache - convert and add it.
-        let res = crate::consts::const_alloc_to_gcc_uncached(self, alloc);
-        self.const_cache.borrow_mut().insert(mock_alloc, res);
-        res
-    }
-
     fn const_ptr_byte_offset(&self, base_addr: Self::Value, offset: abi::Size) -> Self::Value {
         self.context
             .new_array_access(None, base_addr, self.const_usize(offset.bytes()))
@@ -261,17 +261,13 @@ impl<'gcc, 'tcx> ConstCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         self.context.new_cast(None, val, ty)
     }
 
-    fn static_addr_of_const(
-        &self,
-        cv: Self::Value,
-        align: Align,
-        kind: Option<&str>,
-    ) -> Self::Value {
-        self.static_addr_of(cv, align, kind)
+    fn static_addr_of_const(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value {
+        self.static_addr_of(alloc, kind)
     }
 
-    fn static_addr_of_mut(&self, cv: Self::Value, align: Align, kind: Option<&str>) -> Self::Value {
-        self.static_addr_of_mut(cv, align, kind)
+    fn static_addr_of_mut(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value {
+        let cv = self.const_data_from_alloc(alloc);
+        self.static_addr_of_mut(cv, alloc.inner().align, kind)
     }
 }
 
diff --git a/compiler/rustc_codegen_gcc/src/consts.rs b/compiler/rustc_codegen_gcc/src/consts.rs
@@ -35,7 +35,9 @@ fn set_global_alignment<'gcc, 'tcx>(
 }
 
 impl<'gcc, 'tcx> StaticCodegenMethods for CodegenCx<'gcc, 'tcx> {
-    fn static_addr_of(&self, cv: RValue<'gcc>, align: Align, kind: Option<&str>) -> RValue<'gcc> {
+    fn static_addr_of(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> RValue<'gcc> {
+        let align = alloc.inner().align;
+        let cv = self.const_data_from_alloc(alloc);
         if let Some(variable) = self.const_globals.borrow().get(&cv) {
             if let Some(global_variable) = self.global_lvalues.borrow().get(variable) {
                 let alignment = align.bits() as i32;
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
@@ -4,7 +4,7 @@ use std::borrow::Borrow;
 
 use libc::{c_char, c_uint};
 use rustc_abi as abi;
-use rustc_abi::{Align, HasDataLayout};
+use rustc_abi::HasDataLayout;
 use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
 use rustc_hir::def_id::DefId;
@@ -251,10 +251,6 @@ impl<'ll, 'tcx> ConstCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         })
     }
 
-    fn const_data_from_alloc(&self, alloc: ConstAllocation<'_>) -> Self::Value {
-        const_alloc_to_llvm(self, alloc, /*static*/ false)
-    }
-
     fn const_ptr_byte_offset(&self, base_addr: Self::Value, offset: abi::Size) -> Self::Value {
         unsafe {
             llvm::LLVMConstInBoundsGEP2(
@@ -279,17 +275,14 @@ impl<'ll, 'tcx> ConstCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         unsafe { llvm::LLVMConstPtrToInt(val, ty) }
     }
 
-    fn static_addr_of_const(
-        &self,
-        cv: Self::Value,
-        align: Align,
-        kind: Option<&str>,
-    ) -> Self::Value {
-        self.static_addr_of_const(cv, align, kind)
+    fn static_addr_of_const(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value {
+        let cv = const_alloc_to_llvm(self, alloc, /*static*/ false);
+        self.static_addr_of_const(cv, alloc.inner().align, kind)
     }
 
-    fn static_addr_of_mut(&self, cv: Self::Value, align: Align, kind: Option<&str>) -> Self::Value {
-        self.static_addr_of_mut(cv, align, kind)
+    fn static_addr_of_mut(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value {
+        let cv = const_alloc_to_llvm(self, alloc, /*static*/ false);
+        self.static_addr_of_mut(cv, alloc.inner().align, kind)
     }
 }
 
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs
@@ -551,8 +551,9 @@ impl<'ll> StaticCodegenMethods for CodegenCx<'ll, '_> {
     ///
     /// The pointer will always be in the default address space. If global variables default to a
     /// different address space, an addrspacecast is inserted.
-    fn static_addr_of(&self, cv: &'ll Value, align: Align, kind: Option<&str>) -> &'ll Value {
-        let gv = self.static_addr_of_const(cv, align, kind);
+    fn static_addr_of(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> &'ll Value {
+        let cv = const_alloc_to_llvm(self, alloc, /*static*/ false);
+        let gv = self.static_addr_of_const(cv, alloc.inner().align, kind);
         // static_addr_of_const returns the bare global variable, which might not be in the default
         // address space. Cast to the default address space if necessary.
         self.const_pointercast(gv, self.type_ptr())
diff --git a/compiler/rustc_codegen_ssa/src/meth.rs b/compiler/rustc_codegen_ssa/src/meth.rs
@@ -114,9 +114,7 @@ pub(crate) fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
 
     let vtable_alloc_id = tcx.vtable_allocation((ty, trait_ref));
     let vtable_allocation = tcx.global_alloc(vtable_alloc_id).unwrap_memory();
-    let vtable_const = cx.const_data_from_alloc(vtable_allocation);
-    let align = cx.data_layout().pointer_align.abi;
-    let vtable = cx.static_addr_of(vtable_const, align, Some("vtable"));
+    let vtable = cx.static_addr_of(vtable_allocation, Some("vtable"));
 
     cx.apply_vcall_visibility_metadata(ty, trait_ref, vtable);
     cx.create_vtable_debuginfo(ty, trait_ref, vtable);
diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs
@@ -237,8 +237,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
                 // Neither a scalar nor scalar pair. Load from a place
                 // FIXME: should we cache `const_data_from_alloc` to avoid repeating this for the
                 // same `ConstAllocation`?
-                let init = bx.const_data_from_alloc(alloc);
-                let base_addr = bx.static_addr_of(init, alloc_align, None);
+                let base_addr = bx.static_addr_of(alloc, None);
 
                 let llval = bx.const_ptr_byte_offset(base_addr, offset);
                 bx.load_operand(PlaceRef::new_sized(llval, layout))
diff --git a/compiler/rustc_codegen_ssa/src/traits/consts.rs b/compiler/rustc_codegen_ssa/src/traits/consts.rs
@@ -1,4 +1,4 @@
-use rustc_abi::{self as abi, Align, HasDataLayout, Primitive};
+use rustc_abi::{self as abi, HasDataLayout, Primitive};
 use rustc_ast::Mutability;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_hashes::Hash128;
@@ -49,24 +49,17 @@ pub trait ConstCodegenMethods<'tcx>:
     fn const_to_opt_uint(&self, v: Self::Value) -> Option<u64>;
     fn const_to_opt_u128(&self, v: Self::Value, sign_ext: bool) -> Option<u128>;
 
-    fn const_data_from_alloc(&self, alloc: ConstAllocation<'_>) -> Self::Value;
-
     fn const_bitcast(&self, val: Self::Value, ty: Self::Type) -> Self::Value;
     fn const_pointercast(&self, val: Self::Value, ty: Self::Type) -> Self::Value;
     fn const_int_to_ptr(&self, val: Self::Value, ty: Self::Type) -> Self::Value;
     fn const_ptr_to_int(&self, val: Self::Value, ty: Self::Type) -> Self::Value;
     /// Create a global constant.
     ///
     /// The returned global variable is a pointer in the default address space for globals.
-    fn static_addr_of_const(
-        &self,
-        cv: Self::Value,
-        align: Align,
-        kind: Option<&str>,
-    ) -> Self::Value;
+    fn static_addr_of_const(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value;
 
     /// Same as `static_addr_of_const`, but does not mark the static as immutable
-    fn static_addr_of_mut(&self, cv: Self::Value, align: Align, kind: Option<&str>) -> Self::Value;
+    fn static_addr_of_mut(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value;
 
     fn scalar_to_backend(&self, cv: Scalar, layout: abi::Scalar, llty: Self::Type) -> Self::Value {
         let bitsize = if layout.is_bool() { 1 } else { layout.size(self).bits() };
@@ -97,18 +90,16 @@ pub trait ConstCodegenMethods<'tcx>:
                                 self.const_bitcast(llval, llty)
                             };
                         } else {
-                            let init = self.const_data_from_alloc(alloc);
-                            let alloc = alloc.inner();
-                            let value = match alloc.mutability {
-                                Mutability::Mut => self.static_addr_of_mut(init, alloc.align, None),
-                                _ => self.static_addr_of_const(init, alloc.align, None),
+                            let value = match alloc.inner().mutability {
+                                Mutability::Mut => self.static_addr_of_mut(alloc, None),
+                                _ => self.static_addr_of_const(alloc, None),
                             };
                             if !self.tcx().sess.fewer_names()
                                 && self.get_value_name(value).is_empty()
                             {
                                 let hash = self.tcx().with_stable_hashing_context(|mut hcx| {
                                     let mut hasher = StableHasher::new();
-                                    alloc.hash_stable(&mut hcx, &mut hasher);
+                                    alloc.inner().hash_stable(&mut hcx, &mut hasher);
                                     hasher.finish::<Hash128>()
                                 });
                                 self.set_value_name(value, format!("alloc_{hash:032x}").as_bytes());
@@ -127,9 +118,7 @@ pub trait ConstCodegenMethods<'tcx>:
                                 }),
                             )))
                             .unwrap_memory();
-                        let init = self.const_data_from_alloc(alloc);
-                        let value = self.static_addr_of_const(init, alloc.inner().align, None);
-                        value
+                        self.static_addr_of_const(alloc, None)
                     }
                     GlobalAlloc::Static(def_id) => {
                         assert!(self.tcx().is_static(def_id));
diff --git a/compiler/rustc_codegen_ssa/src/traits/statics.rs b/compiler/rustc_codegen_ssa/src/traits/statics.rs
@@ -1,10 +1,10 @@
-use rustc_abi::Align;
 use rustc_hir::def_id::DefId;
+use rustc_middle::mir::interpret::ConstAllocation;
 
 use super::BackendTypes;
 
 pub trait StaticCodegenMethods: BackendTypes {
-    fn static_addr_of(&self, cv: Self::Value, align: Align, kind: Option<&str>) -> Self::Value;
+    fn static_addr_of(&self, alloc: ConstAllocation<'_>, kind: Option<&str>) -> Self::Value;
     fn get_value_name(&self, val: Self::Value) -> &[u8];
     fn set_value_name(&self, val: Self::Value, name: &[u8]);
     fn codegen_static(&mut self, def_id: DefId);
