gcc/testsuite/gcc.target/i386/20011119-1.c

   1 /* Test for reload failing to eliminate from argp to sp.  */
   2 /* { dg-do run { target i?86-*-* x86_64-*-* } } */
   3 /* { dg-require-effective-target ilp32 } */
   4 /* { dg-skip-if "" { "*-*-*" } { "-fpic" "-fPIC" } { "" } } */
   5 /* { dg-skip-if "PIC default" { "*-*-darwin*" } { "*" } { "" } } */
   6 /* { dg-options "-O2 -fomit-frame-pointer" } */
   7
   8 static int ustrsize (const char *s);
   9 static int (*ucwidth) (int c);
  10 static int (*ugetxc) (const char **s);
  11 static int (*usetc) (char *s, int c);
  12
  13 char *ustrzcat(char *dest, int size, const char *src)
  14 {
  15    int pos = ustrsize(dest);
  16    int c;
  17
  18    size -= pos + ucwidth(0);
  19
  20    while ((c = ugetxc(&src)) != 0) {
  21       size -= ucwidth(c);
  22       if (size < 0)
  23          break;
  24
  25       pos += usetc(dest+pos, c);
  26    }
  27
  28    usetc(dest+pos, 0);
  29
  30    return dest;
  31 }
  32
  33 static int __attribute__((noinline))
  34 ustrsize (const char *s)
  35 {
  36   return 0;
  37 }
  38
  39 static int
  40 ucwidth_ (int c)
  41 {
  42   return 1;
  43 }
  44
  45 static int
  46 ugetxc_ (const char **s)
  47 {
  48   return '\0';
  49 }
  50
  51 static int
  52 usetc_ (char *s, int c)
  53 {
  54   return 1;
  55 }
  56
  57 int
  58 main()
  59 {
  60   ucwidth = ucwidth_;
  61   ugetxc = ugetxc_;
  62   usetc = usetc_;
  63
  64   /* ??? It is impossible to explicitly modify the hard frame pointer.
  65      This will run afoul of code in flow.c that declines to mark regs
  66      in eliminate_regs in regs_ever_used.  Apparently, we have to wait
  67      for reload to decide that it won't need a frame pointer before a
  68      variable can be allocated to %ebp.
  69
  70      So save, restore, and clobber %ebp by hand.  */
  71
  72   asm ("pushl %%ebp\n\t"
  73        "movl $-1, %%ebp\n\t"
  74        "pushl $0\n\t"
  75        "pushl $0\n\t"
  76        "pushl $0\n\t"
  77        "call %P0\n\t"
  78        "addl $12, %%esp\n\t"
  79        "popl %%ebp"
  80        : : "i"(ustrzcat) : "memory" );
  81
  82   return 0;
  83 }