Compiler: ti-cgt-c2000_16.9.8.LTS: Possible compiler error?

Other Parts Discussed in Thread: LAUNCHXL-F28379D

Tool/software: TI C/C++ Compiler

I am observing problems with the following code (extracted from a scanf-implementation):

#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>

int my_sscanf(const char *s, char *f, ...) {
  va_list ap;
  int nvars = 0;

  va_start(ap, f);
  while (*f) {
    int lflag = 0, flen = -1, basis = 10;
    unsigned long ulval = 0;

    while (!(*s==0 || !isspace(*s))) s++;
    switch (*f) {
      case '%':
        if (isdigit(*++f)) {
          flen = atoi(f);
          while (isdigit(*f)) f++;
        }
        if (*f == 'l') {f++; lflag = 1;}
        switch (*f++) {
          case 'X' :
          case 'x' : basis = 16;
          case 'u' :
            while (flen-- && (isdigit(*s) || basis==16 && isxdigit(*s))) {
              int d = *s>='a' ? *s-'a'+10 : *s>='A' ? *s-'A'+10 : *s-'0';
              ulval = ulval*basis+d;
              s++;
            }

            if (lflag)
              *((unsigned long *)va_arg(ap, unsigned long *)) = ulval;
            else
              *((unsigned *)va_arg(ap, unsigned *)) = (unsigned) ulval;

            if (flen <= 0) nvars++;
            break;
        }
    }
  }
  va_end(ap);
  return nvars;
}
unsigned long lval = 0;
unsigned val = 0;
/**
 * main.c
 */
int main(void)
{
    my_sscanf("42 24", "%lu%u", &lval, &val);
    return 0;
}

When compiled with

"C:/ti/ccsv7/tools/compiler/ti-cgt-c2000_16.9.8.LTS/bin/cl2000" -v28 -ml -mt --cla_support=cla1 --float_support=fpu32 --tmu_support=tmu0 --vcu_support=vcu2 -O2 --opt_for_speed=3 --include_path="C:/ti/ccsv7/tools/compiler/ti-cgt-c2000_16.9.8.LTS/include" -g --diag_warning=225 --diag_wrap=off --display_error_number --preproc_with_compile --preproc_dependency="main.d_raw"  "../main.c"

and run on a LAUNCHXL-F28379D I'm getting only the first digits of the two numbers 42 and 24 in lval and val respectively.

When compiled with --opt_for_speed values less than 3 I'm getting the expected numbers.

Could this be a compiler bug?

Best regards, Johannes