promote + register loop with intp

Author: SwayamInSync

src/csrc/umath/binary_ops.cpp

@@ -296,8 +296,7 @@ quad_ldexp_resolve_descriptors(PyObject *self, PyArray_DTypeMeta *const dtypes[]
     Py_INCREF(given_descrs[0]);
     loop_descrs[0] = given_descrs[0];
 
-    // Input 1: Use NPY_INTP (int64 on 64-bit, int32 on 32-bit) to match platform integer size
-    // This ensures we can handle the full range of PyArray_PyLongDType without data loss
+    // Input 1: Use NPY_INTP to match the registered PyArray_IntpDType
     loop_descrs[1] = PyArray_DescrFromType(NPY_INTP);
 
     // Output: QuadPrecDType with same backend as input
@@ -408,7 +407,7 @@ create_quad_ldexp_ufunc(PyObject *numpy, const char *ufunc_name)
         return -1;
     }
 
-    PyArray_DTypeMeta *dtypes[3] = {&QuadPrecDType, &PyArray_PyLongDType, &QuadPrecDType};
+    PyArray_DTypeMeta *dtypes[3] = {&QuadPrecDType, &PyArray_IntpDType, &QuadPrecDType};
 
     PyType_Slot slots[] = {
             {NPY_METH_resolve_descriptors, (void *)&quad_ldexp_resolve_descriptors},

src/include/umath/promoters.hpp

@@ -94,9 +94,15 @@ quad_ldexp_promoter(PyUFuncObject *ufunc, PyArray_DTypeMeta *op_dtypes[],
     Py_INCREF(&QuadPrecDType);
     new_op_dtypes[0] = &QuadPrecDType;
 
-    // Preserve the integer type for the exponent (slot 1)
-    Py_INCREF(op_dtypes[1]);
-    new_op_dtypes[1] = op_dtypes[1];
+    // Promote the exponent to PyLongDType (unless signature specifies otherwise)
+    if (signature[1] != NULL) {
+        Py_INCREF(signature[1]);
+        new_op_dtypes[1] = signature[1];
+    }
+    else {
+        Py_INCREF(&PyArray_IntpDType);
+        new_op_dtypes[1] = &PyArray_IntpDType;
+    }
 
     Py_INCREF(&QuadPrecDType);
     new_op_dtypes[2] = &QuadPrecDType;