sdcc/support/regression/tests/bug-2964.c

   1 /*
   2    bug-2964.c
   3
   4    A bug in stm8 code generation for left shift triggered by stack allocation allocating
   5    result and right operands of a left shift to the stack, to overlapping locations.
   6 */
   7
   8 #include <testfwk.h>
   9
  10 unsigned long long j;
  11
  12 unsigned char c;
  13 unsigned long long i;
  14
  15 // Just some function that won't be inlined, so calls to it will result in spilling of local variables.
  16 void g(void)
  17 {
  18         j += 42 + i;
  19 }
  20
  21 unsigned long long f1(void)
  22 {
  23         unsigned char d = c + 1;
  24         j |= 7;
  25         unsigned long long l1 = i + 1;
  26         g();
  27         g();
  28         unsigned long long l2 = l1 << d;
  29
  30         return l2;
  31 }
  32
  33 #ifndef __SDCC_pdk14 // Lack of RAM
  34 unsigned long long f2(void)
  35 {
  36         unsigned char d = c + 1;
  37         j |= 7;
  38         unsigned long long l1 = i + 1;
  39         g();
  40         g();
  41         g();
  42         g();
  43         unsigned long long l2 = l1 << d;
  44
  45         return l2;
  46 }
  47
  48 unsigned long long f3(void)
  49 {
  50         unsigned char d = c + 1;
  51         g();
  52         g();
  53         unsigned long long l2 = i << d;
  54
  55         return l2;
  56 }
  57 #endif
  58
  59 void testBug(void)
  60 {
  61         j = 1;
  62
  63         c = 0;
  64         i = 1;
  65         ASSERT(f1() == 4);
  66
  67 #ifndef __SDCC_pdk14 // Lack of RAM
  68         c = 1;
  69         i = 3;
  70         ASSERT(f2() == 16);
  71
  72         c = 1;
  73         i = 8;
  74         ASSERT(f3() == 32);
  75 #endif
  76 }
  77