Only decorate physically sized types with ArrayStride

Author: jwollen

crates/rustc_codegen_spirv/src/spirv_type.rs

@@ -182,35 +182,15 @@ impl SpirvType<'_> {
             Self::Vector { element, count } => cx.emit_global().type_vector_id(id, element, count),
             Self::Matrix { element, count } => cx.emit_global().type_matrix_id(id, element, count),
             Self::Array { element, count } => {
-                // ArrayStride decoration wants in *bytes*
-                let element_size = cx
-                    .lookup_type(element)
-                    .sizeof(cx)
-                    .expect("Element of sized array must be sized")
-                    .bytes();
-                let mut emit = cx.emit_global();
-                let result = emit.type_array_id(id, element, count.def_cx(cx));
-                emit.decorate(
-                    result,
-                    Decoration::ArrayStride,
-                    iter::once(Operand::LiteralBit32(element_size as u32)),
-                );
+                let result = cx
+                    .emit_global()
+                    .type_array_id(id, element, count.def_cx(cx));
+                self.decorate_array_stride(result, element, cx);
                 result
             }
             Self::RuntimeArray { element } => {
-                let mut emit = cx.emit_global();
-                let result = emit.type_runtime_array_id(id, element);
-                // ArrayStride decoration wants in *bytes*
-                let element_size = cx
-                    .lookup_type(element)
-                    .sizeof(cx)
-                    .expect("Element of sized array must be sized")
-                    .bytes();
-                emit.decorate(
-                    result,
-                    Decoration::ArrayStride,
-                    iter::once(Operand::LiteralBit32(element_size as u32)),
-                );
+                let result = cx.emit_global().type_runtime_array_id(id, element);
+                self.decorate_array_stride(result, element, cx);
                 result
             }
             Self::Pointer { pointee } => {
@@ -278,6 +258,19 @@ impl SpirvType<'_> {
         result
     }
 
+    fn decorate_array_stride(self, result: u32, element: u32, cx: &CodegenCx<'_>) {
+        let mut emit = cx.emit_global();
+        let ty = cx.lookup_type(element);
+        if let Some(element_size) = ty.physical_size(cx) {
+            // ArrayStride decoration wants in *bytes*
+            emit.decorate(
+                result,
+                Decoration::ArrayStride,
+                iter::once(Operand::LiteralBit32(element_size.bytes() as u32)),
+            );
+        }
+    }
+
     /// `def_with_id` is used by the `RecursivePointeeCache` to handle `OpTypeForwardPointer`: when
     /// emitting the subsequent `OpTypePointer`, the ID is already known and must be re-used.
     pub fn def_with_id(self, cx: &CodegenCx<'_>, def_span: Span, id: Word) -> Word {
@@ -386,6 +379,35 @@ impl SpirvType<'_> {
         }
     }
 
+    /// Get the physical size of the type needed for explicit layout decorations.
+    pub fn physical_size(&self, cx: &CodegenCx<'_>) -> Option<Size> {
+        match *self {
+            // TODO(jwollen) Handle physical pointers (PhysicalStorageBuffer)
+            Self::Pointer { .. } => None,
+
+            // TODO(jwollen) Handle unsized elements
+            Self::Adt { size, .. } => size,
+
+            Self::Array { element, count } => Some(
+                cx.lookup_type(element).physical_size(cx)?
+                    * cx.builder
+                        .lookup_const_scalar(count)
+                        .unwrap()
+                        .try_into()
+                        .unwrap(),
+            ),
+
+            // Always unsized types
+            Self::InterfaceBlock { .. } | Self::RayQueryKhr | Self::SampledImage { .. } => None,
+
+            // Descriptor types
+            Self::Image { .. } | Self::AccelerationStructureKhr | Self::Sampler => None,
+
+            // Primitive types
+            ty => ty.sizeof(cx),
+        }
+    }
+
     /// Replace `&[T]` fields with `&'tcx [T]` ones produced by calling
     /// `tcx.arena.dropless.alloc_slice(...)` - this is done late for two reasons:
     /// 1. it avoids allocating in the arena when the cache would be hit anyway,

tests/ui/dis/asm_op_decorate.stderr

@@ -13,17 +13,16 @@ OpExecutionMode %1 OriginUpperLeft
 %2 = OpString "$OPSTRING_FILENAME/asm_op_decorate.rs"
 OpName %3 "asm_op_decorate::main"
 OpName %4 "asm_op_decorate::add_decorate"
-OpDecorate %5 ArrayStride 4
-OpDecorate %6 Binding 0
-OpDecorate %6 DescriptorSet 0
-%7 = OpTypeVoid
-%8 = OpTypeFunction %7
-%9 = OpTypeFloat 32
-%10 = OpTypeImage %9 2D 0 0 0 1 Unknown
-%11 = OpTypeSampledImage %10
-%12 = OpTypePointer UniformConstant %11
-%5 = OpTypeRuntimeArray %11
-%13 = OpTypePointer UniformConstant %5
-%6 = OpVariable  %13  UniformConstant
+OpDecorate %5 Binding 0
+OpDecorate %5 DescriptorSet 0
+%6 = OpTypeVoid
+%7 = OpTypeFunction %6
+%8 = OpTypeFloat 32
+%9 = OpTypeImage %8 2D 0 0 0 1 Unknown
+%10 = OpTypeSampledImage %9
+%11 = OpTypePointer UniformConstant %10
+%12 = OpTypeRuntimeArray %10
+%13 = OpTypePointer UniformConstant %12
+%5 = OpVariable  %13  UniformConstant
 %14 = OpTypeInt 32 0
 %15 = OpConstant  %14  1