This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [Patch, AArch64] Fix shuffle for big-endian.

Alan Lawrence wrote:
Sorry to be pedantic again, but 'wierd' should be spelt 'weird'. Otherwise,
looks good to me and much neater than before. (Seems you'd rather keep the
re-enabling, here and in the testsuite, for another patch?)


Yes, the re-enabling is another patch.

Thanks for the typo correction. OK for trunk with that change?



Tejas Belagod wrote:
Richard Henderson wrote:
On 02/21/2014 08:30 AM, Tejas Belagod wrote:
+      /* If two vectors, we end up with a wierd mixed-endian mode on NEON.  */
+      if (BYTES_BIG_ENDIAN)
+	{
+	  if (!d->one_vector_p && d->perm[i] & nunits)
+	    {
+	      /* Extract the offset.  */
+	      elt = d->perm[i] & (nunits - 1);
+	      /* Reverse the top half.  */
+	      elt = nunits - 1 - elt;
+	      /* Offset it by the bottom half.  */
+	      elt += nunits;
+	    }
+	  else
+	    elt = nunits - 1 - d->perm[i];
+	}
Isn't this just

  elt = d->perm[i] ^ (nunits - 1);

all the time?  I.e. invert the index within the word,
but leave the word index (nunits) unchanged.

Here is a revised patch. OK for stage-1?


2014-04-02  Tejas Belagod  <>


         * config/aarch64/aarch64.c (aarch64_evpc_tbl): Reverse order of elements
	for big-endian.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]