core/ndstrides: rewrite and fix np_reshape() bug

Data content should be copied and strides should be updated after
negative indices are resolved.

nac3core/src/codegen/numpy_new/view.rs

@@ -5,8 +5,9 @@ use crate::{
     codegen::{
         irrt::ndarray::{
             basic::{
-                call_nac3_ndarray_is_c_contiguous, call_nac3_ndarray_nbytes,
+                call_nac3_ndarray_copy_data, call_nac3_ndarray_is_c_contiguous,
-                call_nac3_ndarray_set_strides_by_shape, call_nac3_ndarray_size,
+                call_nac3_ndarray_nbytes, call_nac3_ndarray_set_strides_by_shape,
+                call_nac3_ndarray_size,
             },
             reshape::call_nac3_ndarray_resolve_and_check_new_shape,
         },
@@ -27,51 +28,24 @@ fn gen_reshape_ndarray_or_copy<'ctx, G: CodeGenerator + ?Sized>(
     src_ndarray: Ptr<'ctx, StructModel<NpArray>>,
     new_shape: &ArrayWriter<'ctx, G, SizeT, IntModel<SizeT>>,
 ) -> Result<Ptr<'ctx, StructModel<NpArray>>, String> {
-    /*
-        Reference pseudo-code:
-        ```c
-        NDArray<SizeT>* src_ndarray;
-
-        NDArray<SizeT>* dst_ndarray = __builtin_alloca(...);
-        dst_ndarray->ndims = ...
-        dst_ndarray->strides = __builtin_alloca(...);
-        dst_ndarray->shape = ... // Directly set by user, may contain -1, or even illegal values.
-        dst_ndarray->itemsize = src_ndarray->itemsize;
-        set_strides_by_shape(dst_ndarray);
-
-        // Do assertions on `dst_ndarray->shape` and resolve -1
-
-        resolve_and_check_new_shape(ndarray_size(src_ndarray), dst_ndarray->shape);
-
-        if (is_c_contiguous(src_ndarray)) {
-            dst_ndarray->data = src_ndarray->data;
-        } else {
-            dst_ndarray->data = __builtin_alloca( ndarray_nbytes(dst_ndarray) );
-            copy_data(src_ndarray, dst_ndarray);
-        }
-
-        return dst_ndarray;
-        ```
-    */
-
     let tyctx = generator.type_context(ctx.ctx);
     let byte_model = IntModel(Byte);
 
     let current_bb = ctx.builder.get_insert_block().unwrap();
-    let then_bb = ctx.ctx.insert_basic_block_after(current_bb, "then");
+    let then_bb = ctx.ctx.insert_basic_block_after(current_bb, "then_bb");
     let else_bb = ctx.ctx.insert_basic_block_after(then_bb, "else_bb");
     let end_bb = ctx.ctx.insert_basic_block_after(else_bb, "end_bb");
 
     // Inserting into current_bb
     let dst_ndarray = alloca_ndarray(generator, ctx, new_shape.len, "ndarray").unwrap();
 
+    // Set shape - directly from user input
     init_ndarray_shape(generator, ctx, dst_ndarray, new_shape)?;
     dst_ndarray
         .gep(ctx, |f| f.itemsize)
         .store(ctx, src_ndarray.gep(ctx, |f| f.itemsize).load(tyctx, ctx, "itemsize"));
 
-    call_nac3_ndarray_set_strides_by_shape(generator, ctx, dst_ndarray);
+    // Resolve shape input from user
-
     let src_ndarray_size = call_nac3_ndarray_size(generator, ctx, src_ndarray);
     call_nac3_ndarray_resolve_and_check_new_shape(
         generator,
@@ -81,6 +55,9 @@ fn gen_reshape_ndarray_or_copy<'ctx, G: CodeGenerator + ?Sized>(
         dst_ndarray.gep(ctx, |f| f.shape).load(tyctx, ctx, "shape"),
     );
 
+    // Update strides
+    call_nac3_ndarray_set_strides_by_shape(generator, ctx, dst_ndarray);
+
     let is_c_contiguous = call_nac3_ndarray_is_c_contiguous(generator, ctx, src_ndarray);
     ctx.builder.build_conditional_branch(is_c_contiguous.value, then_bb, else_bb).unwrap();
 
@@ -93,9 +70,12 @@ fn gen_reshape_ndarray_or_copy<'ctx, G: CodeGenerator + ?Sized>(
 
     // Inserting into else_bb: reshape is impossible without copying
     ctx.builder.position_at_end(else_bb);
+    // Allocate data
     let dst_ndarray_nbytes = call_nac3_ndarray_nbytes(generator, ctx, dst_ndarray);
     let data = byte_model.array_alloca(tyctx, ctx, dst_ndarray_nbytes.value, "new_data");
     dst_ndarray.gep(ctx, |f| f.data).store(ctx, data);
+    // Copy content
+    call_nac3_ndarray_copy_data(generator, ctx, src_ndarray, dst_ndarray);
     ctx.builder.build_unconditional_branch(end_bb).unwrap();
 
     // Reposition for continuation