[LLVMdev] GCC DejaGNU regressions

Bill Wendling
Mon, 27 Jul 2009 03:27:12 -0000

On Jul 24, 2009, at 5:01 PM, Stuart Hastings wrote:

> The GCC DejaGNU testsuite has discovered some regressions.  Here's
> one; this was reduced from testsuite/gcc.apple/4656532.c:
>
> typedef long long __m64 __attribute__ ((__vector_size__ (8),
> __may_alias__));
> static __inline __m64 __attribute__((__always_inline__,
> __nodebug__)) _mm_slli_si64 (__m64 __m, int __count) {
> }
> __m64 x, y;
> void t1(int n) {
>  y = _mm_slli_si64(x, n);
> }
>
> Compiled with LLVM-GCC (v76963) on Darwin/x86, this generates an ICE
> in the GCC/LLVM conversion layer.
>
> Here's another test that want's to provoke lots of null pointer
> diagnostics; several such diagnostics are no longer happening, on
> lines 69, 71, 72, 75, 77, and 78:
>
> <nonnull-3.c>
>
>
> Here's another test that aborts at runtime (it's gcc.dg/pr26719.c):
>
> /* { dg-do compile } */
> /* { dg-do run } */
> /* { dg-options "-O2" } */
>
> void abort (void);
>
> int table[32][256];
>
> int main(void)
> {
>  int i, j;
>
>  for (i = 0; i < 32; i++)
>    for (j = 0; j < 256; j++)
>      table[i][j] = ((signed char)j) * i;
>
>  if (table[9][132] != -1116)
>    abort ();
>
>  return 0;
> }
>
> I've only scratched the surface here; my low-priority testing rig
> thinks it has found 400+ regressions.  (It's wrong; it didn't
locate
> libstdc++ this time, so most of the C++ tests failed.)
>
> Do any of these "ring a bell" with anyone?
>
It doesn't sound familiar. Go ahead and file PRs for them. Thanks!

-bw

> The morbidly curious can see the awfulness here.  Warning: there's a
> lot of noise here; the C++ results are mostly useless.
>
> <regressions.txt>
>
>
> Note that this test rig does not record "failures."   Instead,
when
> a test fails, it records that some previous revision of LLVM-GCC
> passed that given test (i.e. it records regressions).  Ergo, a line
> like this:
>
> 	74228.prev/gcc.sum:PASS: gcc.dg/i386-bitfield4.c scan-assembler-not
> movb
>
> says "The r74228 checkout of LLVM-GCC passed the gcc.dg/i386-
> bitfield4.c scan-assembler-not movb test, but the most recent LLVM-
> GCC (r76963) failed."
>
> stuart_______________________________________________
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