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* [Bug target/108787] New: [13 Regression] libsodium miscompilation on power9 starting with r13-2107
@ 2023-02-14 15:59 jakub at gcc dot gnu.org
  2023-02-14 15:59 ` [Bug target/108787] " jakub at gcc dot gnu.org
                   ` (11 more replies)
  0 siblings, 12 replies; 13+ messages in thread
From: jakub at gcc dot gnu.org @ 2023-02-14 15:59 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108787

            Bug ID: 108787
           Summary: [13 Regression] libsodium miscompilation on power9
                    starting with r13-2107
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

The following testcase is miscompiled with -mcpu=power9 -mtune=power9 starting
with
r13-2107-gdefa08a33672d200edbdd7f87ed7afa442249261 .  Doesn't reproduce without
-fPIC though.

/* { dg-do run { target int128 } } */
/* { dg-options "-O2" } */
/* { dg-additional-options "-fPIC" { target fpic } } */

typedef unsigned __int128 uint128_t;

static inline unsigned long long
foo (const unsigned char src[8])
{
  unsigned long long w;
  __builtin_memcpy (&w, src, sizeof w);
  return w;
}

typedef struct S {
  unsigned long long r[3], h[3];
  unsigned char final;
} S;

__attribute__((noipa)) static void
poly1305_blocks (S *st, const unsigned char *m,
                 unsigned long long bytes)
{
  const unsigned long long hibit = st->final ? 0ULL : (1ULL << 40);
  unsigned long long r0, r1, r2;
  unsigned long long s1, s2;
  unsigned long long h0, h1, h2;
  unsigned long long c;
  uint128_t d0, d1, d2, d;

  r0 = st->r[0];
  r1 = st->r[1];
  r2 = st->r[2];
  h0 = st->h[0];
  h1 = st->h[1];
  h2 = st->h[2];
  s1 = r1 * (5 << 2);
  s2 = r2 * (5 << 2);
  while (bytes >= 16)
    {
      unsigned long long t0, t1;

      t0 = foo (&m[0]);
      t1 = foo (&m[8]);
      h0 += t0 & 0xfffffffffff;
      h1 += ((t0 >> 44) | (t1 << 20)) & 0xfffffffffff;
      h2 += (((t1 >> 24)) & 0x3ffffffffff) | hibit;
      d0 = ((uint128_t) h0 * r0);
      d = ((uint128_t) h1 * s2);
      d0 += d;
      d = ((uint128_t) h2 * s1);
      d0 += d;
      d1 = ((uint128_t) h0 * r1);
      d = ((uint128_t) h1 * r0);
      d1 += d;
      d = ((uint128_t) h2 * s2);
      d1 += d;
      d2 = ((uint128_t) h0 * r2);
      d = ((uint128_t) h1 * r1);
      d2 += d;
      d = ((uint128_t) h2 * r0);
      d2 += d;
      c = (unsigned long long) (d0 >> (44));
      h0 = (unsigned long long) (d0) & 0xfffffffffff;
      d1 += c;
      c = (unsigned long long) (d1 >> (44));
      h1 = (unsigned long long) (d1) & 0xfffffffffff;
      d2 += c;
      c = (unsigned long long) (d2 >> (42));
      h2 = (unsigned long long) (d2) & 0x3ffffffffff;
      h0 += c * 5;
      c = (h0 >> 44);
      h0 = h0 & 0xfffffffffff;
      h1 += c;
      m += 16;
      bytes -= 16;
    }
  st->h[0] = h0;
  st->h[1] = h1;
  st->h[2] = h2;
}

int
main ()
{
  if (sizeof (unsigned long long) != 8 || sizeof (uint128_t) != 16)
    return 0;
  S st = { .r = { 0x42c052bac7bULL, 0x7ab6080f47bULL, 0x455e9a405ULL },
           .h = { 0x3efe88da491ULL, 0xd10577b4a44ULL, 0x3efa677b3dbULL } };
  unsigned long long l[2] = { 0, 0x72ULL };
  poly1305_blocks (&st, (unsigned char *) &l[0], sizeof (l));
  if (st.h[0] != 0xef4cd4260ULL || st.h[1] != 0x5d0e836abb6ULL || st.h[2] !=
0x171e724427ULL)
    __builtin_abort ();
  return 0;
}

^ permalink raw reply	[flat|nested] 13+ messages in thread
end of thread, other threads:[~2023-02-15  9:28 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-14 15:59 [Bug target/108787] New: [13 Regression] libsodium miscompilation on power9 starting with r13-2107 jakub at gcc dot gnu.org
2023-02-14 15:59 ` [Bug target/108787] " jakub at gcc dot gnu.org
2023-02-14 16:36 ` jakub at gcc dot gnu.org
2023-02-14 17:00 ` jakub at gcc dot gnu.org
2023-02-14 18:00 ` jakub at gcc dot gnu.org
2023-02-14 18:27 ` jakub at gcc dot gnu.org
2023-02-14 19:19 ` segher at gcc dot gnu.org
2023-02-14 19:30 ` jakub at gcc dot gnu.org
2023-02-14 20:27 ` jakub at gcc dot gnu.org
2023-02-14 20:47 ` segher at gcc dot gnu.org
2023-02-14 20:59 ` segher at gcc dot gnu.org
2023-02-15  9:13 ` cvs-commit at gcc dot gnu.org
2023-02-15  9:28 ` jakub at gcc dot gnu.org

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