Always test in-place addition and subtraction

Run all the addition and subtraction tests with the result aliased to
the first operand and with the result aliased to the second operand.
Before, only some of the aliasing possibilities were tested, for only
some of the functions, with only some inputs.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 2b2daf6..8436742 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -829,6 +829,15 @@
     TEST_ASSERT( mbedtls_mpi_add_mpi( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
+    /* result == first operand */
+    TEST_ASSERT( mbedtls_mpi_add_mpi( &X, &X, &Y ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+
+    /* result == second operand */
+    TEST_ASSERT( mbedtls_mpi_add_mpi( &Y, &X, &Y ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
+
 exit:
     mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
 }
@@ -874,44 +883,17 @@
     TEST_ASSERT( mbedtls_mpi_add_abs( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
-exit:
-    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
-}
-/* END_CASE */
-
-/* BEGIN_CASE */
-void mpi_add_abs_add_first( int radix_X, char * input_X, int radix_Y,
-                            char * input_Y, int radix_A, char * input_A )
-{
-    mbedtls_mpi X, Y, A;
-    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A );
-
-    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+    /* result == first operand */
     TEST_ASSERT( mbedtls_mpi_add_abs( &X, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
-
-exit:
-    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &A );
-}
-/* END_CASE */
-
-/* BEGIN_CASE */
-void mpi_add_abs_add_second( int radix_X, char * input_X, int radix_Y,
-                             char * input_Y, int radix_A, char * input_A )
-{
-    mbedtls_mpi X, Y, A;
-    mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A );
-
     TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
-    TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+
+    /* result == second operand */
     TEST_ASSERT( mbedtls_mpi_add_abs( &Y, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
 
 exit:
-    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &A );
+    mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
 }
 /* END_CASE */
 
@@ -945,6 +927,15 @@
     TEST_ASSERT( mbedtls_mpi_sub_mpi( &Z, &X, &Y ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
+    /* result == first operand */
+    TEST_ASSERT( mbedtls_mpi_sub_mpi( &X, &X, &Y ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+
+    /* result == second operand */
+    TEST_ASSERT( mbedtls_mpi_sub_mpi( &Y, &X, &Y ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
+
 exit:
     mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
 }
@@ -968,6 +959,17 @@
     if( res == 0 )
         TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
 
+    /* result == first operand */
+    TEST_ASSERT( mbedtls_mpi_sub_abs( &X, &X, &Y ) == sub_result );
+    if( sub_result == 0 )
+        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+
+    /* result == second operand */
+    TEST_ASSERT( mbedtls_mpi_sub_abs( &Y, &X, &Y ) == sub_result );
+    if( sub_result == 0 )
+        TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
+
 exit:
     mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
 }