[spv-in] Error on unsupported MatrixStride

src/front/spv/error.rs

@@ -43,6 +43,13 @@ pub enum Error {
     UnsupportedBinaryOperator(spirv::Word),
     #[error("Naga supports OpTypeRuntimeArray in the StorageBuffer storage class only")]
     UnsupportedRuntimeArrayStorageClass,
+    #[error("unsupported matrix stride {stride} for a {columns}x{rows} matrix with scalar width={width}")]
+    UnsupportedMatrixStride {
+        stride: u32,
+        columns: u8,
+        rows: u8,
+        width: u8,
+    },
     #[error("unknown binary operator {0:?}")]
     UnknownBinaryOperator(spirv::Op),
     #[error("unknown relational function {0:?}")]

src/front/spv/mod.rs

@@ -4200,19 +4200,15 @@ impl<I: Iterator<Item = u32>> Parser<I> {
             } = *inner
             {
                 if let Some(stride) = decor.matrix_stride {
-                    let rounded_rows = if rows > crate::VectorSize::Bi {
-                        4
-                    } else {
-                        rows as u32
-                    };
-                    if stride.get() != rounded_rows * (width as u32) {
-                        log::warn!(
-                            "Unexpected matrix stride {} for an {}x{} matrix with scalar width={}",
-                            stride.get(),
-                            columns as u8,
-                            rows as u8,
+                    let aligned_rows = if rows > crate::VectorSize::Bi { 4 } else { 2 };
+                    let expected_stride = aligned_rows * width as u32;
+                    if stride.get() != expected_stride {
+                        return Err(Error::UnsupportedMatrixStride {
+                            stride: stride.get(),
+                            columns: columns as u8,
+                            rows: rows as u8,
                             width,
-                        );
+                        });
                     }
                 }
             }