gcc/testsuite/gcc.dg/const-elim-1.c

   1 /* Verify that constants in memory, referenced only by dead code,
   2    are not emitted to the object file.
   3    FIXME: Not presently possible to apply -pedantic to code with
   4    complex constants in it.  The __extension__ should shut up the
   5    warning but doesn't.  (Hard to fix -- the lexer is not aware of
   6    the parser's state.)  */
   7
   8 /* { dg-do compile } */
   9 /* { dg-options "-O2 -std=c99" } */
  10 /* This test fails on ARM and Xtensa cores because we use a block move to
  11    initialize "S" in test2, and GCC is not clever enough to eliminate
  12    the block move.  */
  13 /* { dg-final { scan-assembler-not "L\\\$?C\[^A-Z\]" { xfail arm-*-* strongarm-*-* xscale-*-* powerpc*-*-aix* xtensa-*-* } } } */
  14
  15 #define I (__extension__ 1.0iF)
  16
  17 struct S { int a; double b[2]; void *c; };
  18
  19 extern void use_str(const char *);
  20 extern void use_S(const struct S *);
  21 extern void use_cplx(__complex__ double);
  22
  23 static inline int
  24 returns_23(void) { return 23; }
  25
  26 void
  27 test1(void)
  28 {
  29         if (returns_23() == 23)
  30                 return;
  31
  32         use_str("waltz, nymph, for quick jigs vex bud");
  33         use_S(&(const struct S){12, {3.1415, 2.1828}, 0 });
  34         use_cplx(3.1415 + 2.1828*I);
  35 }
  36
  37 void
  38 test2(void)
  39 {
  40         const char *str = "pack my box with five dozen liquor jugs";
  41         const struct S S = { 23, { 1.414, 1.618 }, 0 };
  42         const __complex__ double cplx = 1.414 + 1.618*I;
  43
  44         if (returns_23() == 23)
  45                 return;
  46
  47         use_str(str);
  48         use_S(&S);
  49         use_cplx(cplx);
  50 }
  51