gcc/testsuite/gcc.dg/strlenopt-72.c

   1 /* PR tree-optimization/91183 - strlen of a strcpy result with a conditional
   2    source not folded
   3    Test to verify that strlen can determine string lengths from wider stores
   4    than narrow characters.  This matters because on targets that can handle
   5    unaligned stores and where GCC lowers multi-character stores into smaller
   6    numbers of wider stores.
   7    { dg-do compile }
   8    { dg-options "-O2 -fdump-tree-optimized" }
   9    On strictly aligned targets the consecutive char assignments used
  10    by the test aren't merged.  When they involve multiple trailing nuls
  11    these assignments then defeat the strlen optimization as a result of
  12    pr83821.  When the bug is resolved the directive below can be removed.
  13    { dg-require-effective-target non_strict_align } */
  14
  15 #include "strlenopt.h"
  16
  17 #define CAT(x, y) x ## y
  18 #define CONCAT(x, y) CAT (x, y)
  19 #define FAILNAME(name) CONCAT (call_ ## name ##_on_line_, __LINE__)
  20
  21 #define FAIL(name) do {                         \
  22     extern void FAILNAME (name) (void);         \
  23     FAILNAME (name)();                          \
  24   } while (0)
  25
  26 /* Macros to emit a call to function named
  27      call_failed_to_be_eliminated_on_line_NNN()
  28    for each call that's expected to be eliminated.  The dg-final
  29    scan-tree-dump-time directive at the bottom of the test verifies
  30    that no such call appears in output.  */
  31 #define ELIM(expr)                                      \
  32   if ((expr)) FAIL (not_eliminated); else (void)0
  33
  34 #undef T
  35 #define T(N, ncpy, expect, assign) do {                         \
  36     char a[N], b[N];                                            \
  37     assign;                                                     \
  38     memcpy (b, a, ncpy);                                        \
  39     ELIM (!(expect == strlen (b)));                             \
  40   } while (0)
  41
  42 void test_copy (void)
  43 {
  44   T (2, 1, 0, (a[0] = 0));
  45   T (2, 2, 0, (a[0] = 0, a[1] = 0));
  46   T (2, 2, 1, (a[0] = '1', a[1] = 0));
  47   T (4, 3, 2, (a[0] = '1', a[1] = '2', a[2] = 0));
  48   // Not handled due to pr83821:
  49   // T (4, 3, 1, (a[0] = '1', a[1] = 0, a[2] = '2'));
  50   T (4, 2, 1, (a[0] = '1', a[1] = 0,   a[2] = 0,   a[3] = 0));
  51   // Not handled due to pr83821:
  52   // T (4, 3, 1, (a[0] = '1', a[1] = 0,   a[2] = 0,   a[3] = 0));
  53   T (4, 4, 1, (a[0] = '1', a[1] = 0,   a[2] = 0,   a[3] = 0));
  54   T (4, 3, 2, (a[0] = '1', a[1] = '2', a[2] = 0,   a[3] = 0));
  55   T (4, 4, 2, (a[0] = '1', a[1] = '2', a[2] = 0,   a[3] = 0));
  56   T (4, 4, 3, (a[0] = '1', a[1] = '2', a[2] = '3', a[3] = 0));
  57   T (5, 4, 1, (a[0] = '1', a[1] = 0,   a[2] = 0,   a[3] = 0));
  58   T (5, 4, 2, (a[0] = '1', a[1] = '2', a[2] = 0,   a[3] = 0));
  59   T (5, 4, 3, (a[0] = '1', a[1] = '2', a[2] = '3', a[3] = 0));
  60   // Not handled:
  61   // T (5, 5, 1, (a[0] = '1', a[1] = 0,   a[2] = 0,   a[3] = 0,   a[4] = 0));
  62   // T (5, 5, 2, (a[0] = '1', a[1] = '2', a[2] = 0,   a[3] = 0,   a[4] = 0));
  63   // T (5, 5, 3, (a[0] = '1', a[1] = '2', a[2] = '3', a[3] = 0,   a[4] = 0));
  64   T (5, 5, 4, (a[0] = '1', a[1] = '2', a[2] = '3', a[3] = '4', a[4] = 0));
  65 }
  66
  67
  68 /* { dg-final { scan-tree-dump-times "strlen" 0 "optimized" } }
  69    { dg-final { scan-tree-dump-times "_not_eliminated_" 0 "optimized" } } */