use module_shift from base_mode when constructing bitfield modes

diff --git a/ast2firm.c b/ast2firm.c
index 2e85c8a..8a52156 100644 (file)
--- a/ast2firm.c
+++ b/ast2firm.c
@@ -485,10 +485,12 @@ static ir_type *get_signed_int_type_for_bit_size(ir_type *base_tp,
 
        mode = s_modes[size];
        if (mode == NULL) {
-               char name[32];
+               ir_mode *base_mode    = get_type_mode(base_tp);
+               unsigned modulo_shift = get_mode_modulo_shift(base_mode);
 
+               char name[32];
                snprintf(name, sizeof(name), "bf_I%u", size);
-               mode = new_int_mode(name, irma_twos_complement, size, 1, 0);
+               mode = new_int_mode(name, irma_twos_complement, size, 1, modulo_shift);
                s_modes[size] = mode;
        }
 
@@ -517,10 +519,12 @@ static ir_type *get_unsigned_int_type_for_bit_size(ir_type *base_tp,
 
        mode = u_modes[size];
        if (mode == NULL) {
-               char name[32];
+               ir_mode *base_mode    = get_type_mode(base_tp);
+               unsigned modulo_shift = get_mode_modulo_shift(base_mode);
 
+               char name[32];
                snprintf(name, sizeof(name), "bf_U%u", size);
-               mode = new_int_mode(name, irma_twos_complement, size, 0, 0);
+               mode = new_int_mode(name, irma_twos_complement, size, 0, modulo_shift);
                u_modes[size] = mode;
        }