Update activity adjustment logic

Update `count_scalar_fields`->`count_leaf_fields` to support more types
Add extra activities only if `count_scalar_fields` is leq 2
Logic can be optimized if needed
Removed metadata specific fields from test to avoid future fails.

Author: Sa4dUs

compiler/rustc_monomorphize/src/partitioning/autodiff.rs

@@ -84,11 +84,15 @@ fn adjust_activity_to_abi<'tcx>(tcx: TyCtxt<'tcx>, fn_ty: Ty<'tcx>, da: &mut Vec
 
         let is_product = |t: Ty<'tcx>| matches!(t.kind(), ty::Tuple(_) | ty::Adt(_, _));
 
+        // NOTE: When an ADT (Algebraic Data Type) has fewer than two fields and a total size less than pointer_size * 2,
+        // LLVM will pass its fields separately instead of as a single aggregate.
         if layout.size() <= pointer_size * 2 && is_product(*ty) {
-            let n_scalars = count_scalar_fields(tcx, *ty);
-            for _ in 0..n_scalars.saturating_sub(1) {
-                new_activities.push(da[i].clone());
-                new_positions.push(i + 1);
+            let n_scalars = count_leaf_fields(tcx, *ty);
+            if n_scalars <= 2 {
+                for _ in 0..n_scalars.saturating_sub(1) {
+                    new_activities.push(da[i].clone());
+                    new_positions.push(i + 1);
+                }
             }
         }
     }
@@ -101,16 +105,25 @@ fn adjust_activity_to_abi<'tcx>(tcx: TyCtxt<'tcx>, fn_ty: Ty<'tcx>, da: &mut Vec
     }
 }
 
-fn count_scalar_fields<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> usize {
+fn count_leaf_fields<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> usize {
     match ty.kind() {
-        ty::Float(_) | ty::Int(_) | ty::Uint(_) => 1,
+        ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::FnPtr(_, _) => 1,
+        ty::RawPtr(ty, _) => count_leaf_fields(tcx, *ty),
+        ty::Ref(_, ty, _) => count_leaf_fields(tcx, *ty),
+        ty::Array(ty, len) => {
+            if let Some(len) = len.try_to_target_usize(tcx) {
+                count_leaf_fields(tcx, *ty) * len as usize
+            } else {
+                1 // Not sure about how to handle this case
+            }
+        }
         ty::Adt(def, substs) if def.is_struct() => def
             .non_enum_variant()
             .fields
             .iter()
-            .map(|f| count_scalar_fields(tcx, f.ty(tcx, substs)))
+            .map(|f| count_leaf_fields(tcx, f.ty(tcx, substs)))
             .sum(),
-        ty::Tuple(substs) => substs.iter().map(|t| count_scalar_fields(tcx, t)).sum(),
+        ty::Tuple(substs) => substs.iter().map(|t| count_leaf_fields(tcx, t)).sum(),
         _ => 0,
     }
 }

tests/codegen/autodiff/abi_handling.rs

@@ -101,6 +101,17 @@ fn f6(i: NestedInput) -> f32 {
     i.x + i.y.z * i.y.z
 }
 
+// CHECK: ; abi_handling::f7
+// CHECK-NEXT: ; Function Attrs: {{.*}}noinline{{.*}}
+// debug-NEXT: define internal float @_ZN12abi_handling2f717h44e3cff234e3b2d5E
+// debug-SAME: (ptr align 4 %x.0, ptr align 4 %x.1)
+// release-NEXT: define internal fastcc noundef float @_ZN12abi_handling2f717h44e3cff234e3b2d5E
+// release-SAME: (float %x.0.0.val, float %x.1.0.val)
+#[autodiff_forward(df7, Dual, Dual)]
+fn f7(x: (&f32, &f32)) -> f32 {
+    x.0 * x.1
+}
+
 // df1
 // release: define internal fastcc { float, float }
 // release-SAME: @fwddiffe_ZN12abi_handling2f117h536ac8081c1e4101E
@@ -117,12 +128,12 @@ fn f6(i: NestedInput) -> f32 {
 // debug-NEXT: start:
 // debug-NEXT: %"'ipg" = getelementptr inbounds float, ptr %"x'", i64 0
 // debug-NEXT: %0 = getelementptr inbounds nuw float, ptr %x, i64 0
-// debug-NEXT: %"_2'ipl" = load float, ptr %"'ipg", align 4, !alias.scope !4, !noalias !7
-// debug-NEXT: %_2 = load float, ptr %0, align 4, !alias.scope !7, !noalias !4
+// debug-NEXT: %"_2'ipl" = load float, ptr %"'ipg", align 4
+// debug-NEXT: %_2 = load float, ptr %0, align 4
 // debug-NEXT: %"'ipg2" = getelementptr inbounds float, ptr %"x'", i64 1
 // debug-NEXT: %1 = getelementptr inbounds nuw float, ptr %x, i64 1
-// debug-NEXT: %"_5'ipl" = load float, ptr %"'ipg2", align 4, !alias.scope !4, !noalias !7
-// debug-NEXT: %_5 = load float, ptr %1, align 4, !alias.scope !7, !noalias !4
+// debug-NEXT: %"_5'ipl" = load float, ptr %"'ipg2", align 4
+// debug-NEXT: %_5 = load float, ptr %1, align 4
 // debug-NEXT: %_0 = fadd float %_2, %_5
 // debug-NEXT: %2 = fadd fast float %"_2'ipl", %"_5'ipl"
 // debug-NEXT: %3 = insertvalue { float, float } undef, float %_0, 0
@@ -147,7 +158,7 @@ fn f6(i: NestedInput) -> f32 {
 // debug-NEXT: %"x'de" = alloca float, align 4
 // debug-NEXT: store float 0.000000e+00, ptr %"x'de", align 4
 // debug-NEXT: %toreturn = alloca float, align 4
-// debug-NEXT: %_0 = call float %f(float %x) #12
+// debug-NEXT: %_0 = call float %f(float %x)
 // debug-NEXT: store float %_0, ptr %toreturn, align 4
 // debug-NEXT: br label %invertstart
 // debug-EMPTY:
@@ -172,10 +183,10 @@ fn f6(i: NestedInput) -> f32 {
 // debug: define internal { float, float } @fwddiffe_ZN12abi_handling2f317h9cd1fc602b0815a4E
 // debug-SAME: (ptr align 4 %x, ptr align 4 %"x'", ptr align 4 %y, ptr align 4 %"y'")
 // debug-NEXT: start:
-// debug-NEXT: %"_3'ipl" = load float, ptr %"x'", align 4, !alias.scope !9, !noalias !12
-// debug-NEXT: %_3 = load float, ptr %x, align 4, !alias.scope !12, !noalias !9
-// debug-NEXT: %"_4'ipl" = load float, ptr %"y'", align 4, !alias.scope !14, !noalias !17
-// debug-NEXT: %_4 = load float, ptr %y, align 4, !alias.scope !17, !noalias !14
+// debug-NEXT: %"_3'ipl" = load float, ptr %"x'", align 4
+// debug-NEXT: %_3 = load float, ptr %x, align 4
+// debug-NEXT: %"_4'ipl" = load float, ptr %"y'", align 4
+// debug-NEXT: %_4 = load float, ptr %y, align 4
 // debug-NEXT: %_0 = fmul float %_3, %_4
 // debug-NEXT: %0 = fmul fast float %"_3'ipl", %_4
 // debug-NEXT: %1 = fmul fast float %"_4'ipl", %_3
@@ -257,6 +268,28 @@ fn f6(i: NestedInput) -> f32 {
 // debug-NEXT: ret { float, float } %5
 // debug-NEXT: }
 
+// df7
+// release: define internal fastcc { float, float }
+// release-SAME: @fwddiffe_ZN12abi_handling2f717h44e3cff234e3b2d5E
+// release-SAME: (float %x.0.0.val, float %"x.0'.0.val")
+// release-NEXT: start:
+// release-NEXT: %0 = insertvalue { float, float } undef, float %x.0.0.val, 0
+// release-NEXT: %1 = insertvalue { float, float } %0, float %"x.0'.0.val", 1
+// release-NEXT: ret { float, float } %1
+// release-NEXT: }
+
+// debug: define internal { float, float }
+// debug-SAME: @fwddiffe_ZN12abi_handling2f717h44e3cff234e3b2d5E
+// debug-SAME: (ptr align 4 %x.0, ptr align 4 %"x.0'", ptr align 4 %x.1, ptr align 4 %"x.1'")
+// debug-NEXT: start:
+// debug-NEXT: %0 = call fast { float, float } @"fwddiffe_ZN49_{{.*}}"
+// debug-NEXT: %1 = extractvalue { float, float } %0, 0
+// debug-NEXT: %2 = extractvalue { float, float } %0, 1
+// debug-NEXT: %3 = insertvalue { float, float } undef, float %1, 0
+// debug-NEXT: %4 = insertvalue { float, float } %3, float %2, 1
+// debug-NEXT: ret { float, float } %4
+// debug-NEXT: }
+
 fn main() {
     let x = std::hint::black_box(2.0);
     let y = std::hint::black_box(3.0);
@@ -290,4 +323,9 @@ fn main() {
     dbg!(f6(in_f6));
     let res_f6 = df6(in_f6, NestedInput { x, y: Wrapper { z } });
     dbg!(res_f6);
+
+    let in_f7 = (&x, &y);
+    dbg!(f7(in_f7));
+    let res_f7 = df7(in_f7, (&1.0, &0.0));
+    dbg!(res_f7);
 }