memcheck/tests/amd64/insn-pcmpistri.c

   1 /* https://bugs.kde.org/show_bug.cgi?id=309921 */
   2
   3 #define _XOPEN_SOURCE 600 /* for posix_memalign() */
   4
   5 #include "../../memcheck.h"
   6
   7 #include <stdio.h>
   8 #include <assert.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11
  12 /* Exercise pcmpistri instruction in a realistic way. */
  13 int aligned_strlen(const char *const s)
  14 {
  15    assert(((unsigned long)s & 0x0F) == 0);
  16
  17    const char *p = s;
  18
  19    /* volatile asm and "memory" clobber are needed here, since we
  20       access memory in ways we cannot describe to GCC. */
  21    __asm__ __volatile__ ("\n1:\n"
  22                          "\tmovdqa (%0),%%xmm6\n"
  23                          "\tpcmpistri $0x3a,%%xmm6,%%xmm6\n"
  24                          "\tjc 2f\n"
  25                          "\tadd $0x10,%0\n"
  26                          "\tjmp 1b\n"
  27                          "2:\n"
  28                          "\tadd %%rcx,%0\n"
  29                          : "=p" (p) : "0" (p) : "xmm6", "rcx", "cc", "memory");
  30
  31    return p-s;
  32 }
  33
  34 /* Compute strlen(s).  Arrange for result to be valid or invalid
  35    according to second argument. */
  36 int test_strlen(const char *const s, int valid)
  37 {
  38    /* len = length of string including trailing null */
  39    const size_t len = strlen(s) + 1;
  40    const size_t roundup = ((len+15)/16)*16;
  41    int result = -1;
  42
  43    void *space;
  44    posix_memalign(&space, 16, roundup);
  45    memset(space, 'x', roundup);
  46    memcpy(space, s, len);
  47
  48    const char *const s_copy = space;
  49    const unsigned char ff = 0xFF;
  50    if (valid) {
  51       /* Mark all bytes beyond the null as invalid. */
  52       size_t i;
  53       for (i=len ; i < roundup ; ++i)
  54          (void)VALGRIND_SET_VBITS(&s_copy[i], &ff, 1);
  55    }
  56    else {
  57       /* Mark the null byte itself as invalid. */
  58       assert(len > 0);
  59       (void)VALGRIND_SET_VBITS(&s_copy[len-1], &ff, 1);
  60    }
  61
  62    result = aligned_strlen(s_copy);
  63
  64    free(space);
  65
  66    return result;
  67 }
  68
  69 void doit(const char *const s)
  70 {
  71    printf("strlen(\"%s\")=%d\n", s, test_strlen(s, 1));
  72
  73    fprintf(stderr, "strlen(\"%s\")=%s\n", s,
  74            test_strlen(s, 0) ? "true" : "false");
  75 }
  76
  77 int main(int argc, char *argv[])
  78 {
  79    doit("");
  80    doit("a");
  81    doit("ab");
  82    doit("abc");
  83    doit("abcd");
  84    doit("abcde");
  85    doit("abcdef");
  86    doit("abcdefg");
  87    /* 8 */
  88    doit("abcdefgh");
  89    doit("abcdefghi");
  90    doit("abcdefghij");
  91    doit("abcdefghijk");
  92    doit("abcdefghijkl");
  93    doit("abcdefghijklm");
  94    doit("abcdefghijklmn");
  95    doit("abcdefghijklmno");
  96    /* 16 */
  97    doit("abcdefghijklmnop");
  98    doit("abcdefghijklmnopq");
  99    doit("abcdefghijklmnopqr");
 100    doit("abcdefghijklmnopqrs");
 101    doit("abcdefghijklmnopqrst");
 102    doit("abcdefghijklmnopqrstu");
 103    doit("abcdefghijklmnopqrstuv");
 104    doit("abcdefghijklmnopqrstuvw");
 105    doit("abcdefghijklmnopqrstuwvx");
 106    doit("abcdefghijklmnopqrstuwvxy");
 107    doit("abcdefghijklmnopqrstuwvxyz");
 108    /* 255 */
 109    doit("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 110         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 111         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 112         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
 113    /* 256 */
 114    doit("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 115         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 116         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 117         "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
 118    return 0;
 119 }