[PATCH, rs6000] gimple folding support for vec_pack and vec_unpack

[Will Schmidt]

Hi,
  Add support for gimple folding for vec_pack(), vec_unpackh() and
vec_unpackl().
Testcases for vec_pack are already in tree. Tests for vec_unpack
have been posted separately.
OK for trunk?

Thanks,
-Will

[gcc]

2018-07-09 Will Schmidt  

* config/rs6000/rs6000.c (rs6000_gimple_fold_builtin):
Add support for gimple-folding of vec_pack() and vec_unpack()
intrinsics.


diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 774c60a..1335661 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -16100,10 +16100,65 @@ rs6000_gimple_fold_builtin (gimple_stmt_iterator *gsi)
 case VSX_BUILTIN_XXMRGHW_4SI:
 case ALTIVEC_BUILTIN_VMRGHB:
 case VSX_BUILTIN_VEC_MERGEH_V2DI:
fold_mergehl_helper (gsi, stmt, 0);
return true;
+
+/* d = vec_pack (a, b) */
+case P8V_BUILTIN_VPKUDUM:
+case ALTIVEC_BUILTIN_VPKUHUM:
+case ALTIVEC_BUILTIN_VPKUWUM:
+  {
+   arg0 = gimple_call_arg (stmt, 0);
+   arg1 = gimple_call_arg (stmt, 1);
+   lhs = gimple_call_lhs (stmt);
+   gimple *g = gimple_build_assign (lhs, VEC_PACK_TRUNC_EXPR, arg0, arg1);
+   gimple_set_location (g, gimple_location (stmt));
+   gsi_replace (gsi, g, true);
+   return true;
+  }
+
+   /* d = vec_unpackh (a) */
+   /* Note that the UNPACK_{HI,LO}_EXPR used in the gimple_build_assign call
+  in this code is sensitive to endian-ness, and needs to be inverted to
+  handle both LE and BE targets.  */
+case ALTIVEC_BUILTIN_VUPKHSB:
+case ALTIVEC_BUILTIN_VUPKHSH:
+case P8V_BUILTIN_VUPKHSW:
+  {
+   arg0 = gimple_call_arg (stmt, 0);
+   lhs = gimple_call_lhs (stmt);
+   if (BYTES_BIG_ENDIAN)
+g = gimple_build_assign (lhs, VEC_UNPACK_HI_EXPR, arg0);
+   else
+g = gimple_build_assign (lhs, VEC_UNPACK_LO_EXPR, arg0);
+   gimple_set_location (g, gimple_location (stmt));
+   gsi_replace (gsi, g, true);
+   return true;
+  }
+   /* d = vec_unpackl (a) */
+case ALTIVEC_BUILTIN_VUPKLSB:
+case ALTIVEC_BUILTIN_VUPKLSH:
+case P8V_BUILTIN_VUPKLSW:
+  {
+   arg0 = gimple_call_arg (stmt, 0);
+   lhs = gimple_call_lhs (stmt);
+   if (BYTES_BIG_ENDIAN)
+g = gimple_build_assign (lhs, VEC_UNPACK_LO_EXPR, arg0);
+   else
+g = gimple_build_assign (lhs, VEC_UNPACK_HI_EXPR, arg0);
+   gimple_set_location (g, gimple_location (stmt));
+   gsi_replace (gsi, g, true);
+   return true;
+  }
+/* There is no gimple type corresponding with pixel, so just return.  */
+case ALTIVEC_BUILTIN_VUPKHPX:
+case ALTIVEC_BUILTIN_VUPKLPX:
+  {
+   return false;
+  }
+
 default:
   if (TARGET_DEBUG_BUILTIN)
fprintf (stderr, "gimple builtin intrinsic not matched:%d %s %s\n",
 fn_code, fn_name1, fn_name2);
   break;

Re: [PATCH, rs6000] gimple folding support for vec_pack and vec_unpack

[Segher Boessenkool]

Hi!

On Mon, Jul 09, 2018 at 02:08:37PM -0500, Will Schmidt wrote:
>   * config/rs6000/rs6000.c (rs6000_gimple_fold_builtin):
>   Add support for gimple-folding of vec_pack() and vec_unpack()
>   intrinsics.

> +case ALTIVEC_BUILTIN_VUPKHPX:
> +case ALTIVEC_BUILTIN_VUPKLPX:
> +  {
> +   return false;
> +  }

A block around a signle statement looks a bit silly (and in the other
cases in your patch it isn't necessary either; it is nice if you use it
to give some scope to a local var, but you don't have that here).

But, patch is fine as far as I can see :-)


Segher