Bignum tests: improve mod descriptions

There are no semantic changes to the generated tests.

Signed-off-by: Janos Follath <janos.follath@arm.com>

scripts/mbedtls_dev/bignum_common.py

@@ -168,9 +168,14 @@ class OperationCommon(test_data_generation.BaseTest):
         generated to provide some context to the test case.
         """
         if not self.case_description:
-            self.case_description = "{:x} {} {:x}".format(
-                self.int_a, self.symbol, self.int_b
-            )
+            if self.arity == 1:
+                self.case_description = "{} {:x}".format(
+                    self.symbol, self.int_a
+                )
+            elif self.arity == 2:
+                self.case_description = "{:x} {} {:x}".format(
+                    self.int_a, self.symbol, self.int_b
+                )
         return super().description()
 
     @property
@@ -232,7 +237,6 @@ class OperationCommon(test_data_generation.BaseTest):
                     )
 
 
-
 class ModOperationCommon(OperationCommon):
     #pylint: disable=abstract-method
     """Target for bignum mod_raw test case generation."""
@@ -278,6 +282,17 @@ class ModOperationCommon(OperationCommon):
             return False
         return True
 
+    def description(self) -> str:
+        """Generate a description for the test case.
+
+        It uses the form A `symbol` B mod N, where symbol is used to represent
+        the operation.
+        """
+
+        if not self.case_description:
+            return super().description() + " mod {:x}".format(self.int_n)
+        return super().description()
+
     @classmethod
     def input_cases_args(cls) -> Iterator[Tuple[Any, Any, Any]]:
         if cls.arity == 1:

scripts/mbedtls_dev/bignum_mod_raw.py

@@ -55,6 +55,7 @@ class BignumModRawConvertToMont(bignum_common.ModOperationCommon,
 
     test_function = "mpi_mod_raw_to_mont_rep"
     test_name = "Convert into Mont: "
+    symbol = "R *"
     input_style = "arch_split"
     arity = 1
 
@@ -108,24 +109,17 @@ class BignumModRawConvertToMont(bignum_common.ModOperationCommon,
                     "947fb3baf674f74a673cf1d38126983a19ed52c7439fab42c2185"
                     ]
 
-    descr_tpl = '{} #{} N: \"{}\" A: \"{}\".'
-
     def result(self) -> List[str]:
         result = (self.int_a * self.r) % self.int_n
         return [self.format_result(result)]
 
-    def description(self) -> str:
-        return self.descr_tpl.format(self.test_name,
-                                     self.count,
-                                     self.int_n,
-                                     self.int_a)
-
 
 class BignumModRawConvertFromMont(BignumModRawConvertToMont):
     """ Test cases for mpi_mod_raw_from_mont_rep(). """
-
+    count = 0
     test_function = "mpi_mod_raw_from_mont_rep"
     test_name = "Convert from Mont: "
+    symbol = "1/R *"
 
     input_values = ["0",
                     "1",