Fix (u)int8 upcasting as per docs and numpy (#650)

* fix wrong #if guard in ndarray_inplace_ams

* implement (u)int8 upcasting rules as per documentation

* bump version

Author: s-ol

code/ndarray_operators.c

@@ -181,8 +181,8 @@ mp_obj_t ndarray_binary_add(ndarray_obj_t *lhs, ndarray_obj_t *rhs,
 
     if(lhs->dtype == NDARRAY_UINT8) {
         if(rhs->dtype == NDARRAY_UINT8) {
-            results = ndarray_new_dense_ndarray(ndim, shape, NDARRAY_UINT16);
-            BINARY_LOOP(results, uint16_t, uint8_t, uint8_t, larray, lstrides, rarray, rstrides, +);
+            results = ndarray_new_dense_ndarray(ndim, shape, NDARRAY_UINT8);
+            BINARY_LOOP(results, uint8_t, uint8_t, uint8_t, larray, lstrides, rarray, rstrides, +);
         } else if(rhs->dtype == NDARRAY_INT8) {
             results = ndarray_new_dense_ndarray(ndim, shape, NDARRAY_INT16);
             BINARY_LOOP(results, int16_t, uint8_t, int8_t, larray, lstrides, rarray, rstrides, +);
@@ -264,8 +264,8 @@ mp_obj_t ndarray_binary_multiply(ndarray_obj_t *lhs, ndarray_obj_t *rhs,
 
     if(lhs->dtype == NDARRAY_UINT8) {
         if(rhs->dtype == NDARRAY_UINT8) {
-            results = ndarray_new_dense_ndarray(ndim, shape, NDARRAY_UINT16);
-            BINARY_LOOP(results, uint16_t, uint8_t, uint8_t, larray, lstrides, rarray, rstrides, *);
+            results = ndarray_new_dense_ndarray(ndim, shape, NDARRAY_UINT8);
+            BINARY_LOOP(results, uint8_t, uint8_t, uint8_t, larray, lstrides, rarray, rstrides, *);
         } else if(rhs->dtype == NDARRAY_INT8) {
             results = ndarray_new_dense_ndarray(ndim, shape, NDARRAY_INT16);
             BINARY_LOOP(results, int16_t, uint8_t, int8_t, larray, lstrides, rarray, rstrides, *);
@@ -1059,7 +1059,7 @@ mp_obj_t ndarray_inplace_ams(ndarray_obj_t *lhs, ndarray_obj_t *rhs, int32_t *rs
         UNWRAP_INPLACE_OPERATOR(lhs, larray, rarray, rstrides, +=);
     }
     #endif
-    #if NDARRAY_HAS_INPLACE_ADD
+    #if NDARRAY_HAS_INPLACE_MULTIPLY
     if(optype == MP_BINARY_OP_INPLACE_MULTIPLY) {
         UNWRAP_INPLACE_OPERATOR(lhs, larray, rarray, rstrides, *=);
     }

code/ulab.c

@@ -33,7 +33,7 @@
 #include "user/user.h"
 #include "utils/utils.h"
 
-#define ULAB_VERSION 6.4.1
+#define ULAB_VERSION 6.4.2
 #define xstr(s) str(s)
 #define str(s) #s
 

docs/ulab-change-log.md

@@ -1,3 +1,9 @@
+Thu, 11 Dec 2023
+
+version 6.4.2
+
+    fix upcasting with two uint8 operands (#650)
+
 Thu, 10 Aug 2023
 
 version 6.4.1

tests/2d/numpy/operators.py.exp

@@ -94,7 +94,7 @@ array([1.0, 2.0, 3.0], dtype=float64)
 array([1.0, 32.0, 729.0], dtype=float64)
 array([1.0, 32.0, 729.0], dtype=float64)
 array([1.0, 32.0, 729.0], dtype=float64)
-array([5, 7, 9], dtype=uint16)
+array([5, 7, 9], dtype=uint8)
 array([5, 7, 9], dtype=int16)
 array([5, 7, 9], dtype=int8)
 array([5, 7, 9], dtype=uint16)