Re: [PATCH, rs6000] Add support for gimple folding vec_perm()

[Segher Boessenkool]

On Mon, Jul 09, 2018 at 02:08:55PM -0500, Will Schmidt wrote:
>Add support for early gimple folding of vec_perm.   Testcases are already 
> in-tree as
> gcc.target/powerpc/fold-vec-perm-*.c
> 
> OK for trunk?

Looks fine to me.  Okay if no one else complains :-)


Segher


>   * gcc/config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Add support
>   for folding vec_perm.

[PATCH, rs6000] Add support for gimple folding vec_perm()

[Will Schmidt]

 Hi,
   Add support for early gimple folding of vec_perm.   Testcases are already 
in-tree as
gcc.target/powerpc/fold-vec-perm-*.c

OK for trunk?

Thanks,
-Will

[gcc]

2018-07-09  Will Schmidt  

* gcc/config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Add support
for folding vec_perm.

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 1335661..7e4370c9 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -16155,10 +16155,41 @@ rs6000_gimple_fold_builtin (gimple_stmt_iterator *gsi)
 case ALTIVEC_BUILTIN_VUPKLPX:
   {
return false;
   }
 
+/* vec_perm.  */
+case ALTIVEC_BUILTIN_VPERM_16QI:
+case ALTIVEC_BUILTIN_VPERM_8HI:
+case ALTIVEC_BUILTIN_VPERM_4SI:
+case ALTIVEC_BUILTIN_VPERM_2DI:
+case ALTIVEC_BUILTIN_VPERM_4SF:
+case ALTIVEC_BUILTIN_VPERM_2DF:
+  {
+   arg0 = gimple_call_arg (stmt, 0);
+   arg1 = gimple_call_arg (stmt, 1);
+   tree permute = gimple_call_arg (stmt, 2);
+   lhs = gimple_call_lhs (stmt);
+   location_t loc = gimple_location (stmt);
+   gimple_seq stmts = NULL;
+   // convert arg0 and arg1 to match the type of the permute
+   // for the VEC_PERM_EXPR operation.
+   tree permute_type = (TREE_TYPE (permute));
+   tree arg0_ptype = gimple_convert (&stmts, loc, permute_type, arg0);
+   tree arg1_ptype = gimple_convert (&stmts, loc, permute_type, arg1);
+   tree lhs_ptype = gimple_build (&stmts, loc, VEC_PERM_EXPR,
+ permute_type, arg0_ptype, arg1_ptype,
+ permute);
+   // Convert the result back to the desired lhs type upon completion.
+   tree temp = gimple_convert (&stmts, loc, TREE_TYPE (lhs), lhs_ptype);
+   gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
+   g = gimple_build_assign (lhs, temp);
+   gimple_set_location (g, loc);
+   gsi_replace (gsi, g, true);
+   return true;
+  }
+
 default:
   if (TARGET_DEBUG_BUILTIN)
fprintf (stderr, "gimple builtin intrinsic not matched:%d %s %s\n",
 fn_code, fn_name1, fn_name2);
   break;