Roger pinged this on gcc-patches some time ago fwiw.
[The commit-hooks will likely fix or ignore s/bext/next/ in his
mail-addr]
On Sun, 14 Jun 2020 23:39:32 +0100
"Roger Sayle" <ro...@nextmovesoftware.com> wrote:
>
>
> The following patch to gfortran's trans-instrinsic.c tweaks the generic that
> is produced
>
> for popcnt on integer(kind=16). Currently, the double word popcnt is
> implemented as
>
> parityll(hipart(x))^parityll(lopart(x)), but with this patch this is now
> translated as
>
> parityll(hipart(x)^lopart(x)). This will be just an aesthetic change once
> my tree-level
>
> parity optimization patch of 12th June is reviewed and accepted, but
> generating the
>
> more efficient form initially, avoids a tiny bit of garbage collection when
> the middle-end
>
> cleans this up into its preferred form. The semantics/correctness of this
>
> change are tested by the run-time tests in gfortran.dg/popcnt_poppar_2.F90
>
>
>
> This patch has been tested with "make bootstrap" and "make -k check" on
>
> x86_64-pc-linux-gnu with no regressions. If approved, I'd very much
>
> appreciate it if the (gfortran) reviewer could commit this change for me.
>
>
>
> 2020-06-14 Roger Sayle <ro...@bextmovesoftware.com>
>
>
>
> * trans-intrinsic.c (gfc_conv_intrinsic_popcnt_poppar): Translate
>
> poppar(kind=16) as parityll(hipart(x)^lopart(x)) instead of
>
> parityll(hipart(x))^parityll(lopart(x)).
>
>
>
>
>
> Thanks in advance,
>
> Roger
>
> --
>
> Roger Sayle
>
> NextMove Software
>
> Cambridge, UK
>
>
>
diff --git a/gcc/fortran/trans-intrinsic.c b/gcc/fortran/trans-intrinsic.c
index fd88099..363874e 100644
--- a/gcc/fortran/trans-intrinsic.c
+++ b/gcc/fortran/trans-intrinsic.c
@@ -7153,35 +7153,39 @@ gfc_conv_intrinsic_popcnt_poppar (gfc_se * se, gfc_expr
*expr, int parity)
as 'long long'. */
gcc_assert (argsize == 2 * LONG_LONG_TYPE_SIZE);
- func = builtin_decl_explicit (parity
- ? BUILT_IN_PARITYLL
- : BUILT_IN_POPCOUNTLL);
-
/* Convert it to an integer, and store into a variable. */
utype = gfc_build_uint_type (argsize);
arg = fold_convert (utype, arg);
arg = gfc_evaluate_now (arg, &se->pre);
-
- /* Call the builtin twice. */
- call1 = build_call_expr_loc (input_location, func, 1,
- fold_convert (long_long_unsigned_type_node,
- arg));
-
- arg2 = fold_build2_loc (input_location, RSHIFT_EXPR, utype, arg,
- build_int_cst (utype, LONG_LONG_TYPE_SIZE));
- call2 = build_call_expr_loc (input_location, func, 1,
- fold_convert (long_long_unsigned_type_node,
- arg2));
+ arg_type = long_long_unsigned_type_node;
/* Combine the results. */
if (parity)
- se->expr = fold_build2_loc (input_location, BIT_XOR_EXPR, result_type,
- call1, call2);
+ {
+ /* Construct parityll (LOPART (arg) ^ HIPART (arg)) */
+ arg2 = fold_build2_loc (input_location, RSHIFT_EXPR, utype, arg,
+ build_int_cst (utype, LONG_LONG_TYPE_SIZE));
+ arg = fold_build2_loc (input_location, BIT_XOR_EXPR, arg_type,
+ fold_convert (arg_type, arg),
+ fold_convert (arg_type, arg2));
+ func = builtin_decl_explicit (BUILT_IN_PARITYLL);
+ argsize = LONG_LONG_TYPE_SIZE;
+ }
else
- se->expr = fold_build2_loc (input_location, PLUS_EXPR, result_type,
- call1, call2);
-
- return;
+ {
+ func = builtin_decl_explicit (BUILT_IN_POPCOUNTLL);
+
+ /* Call the builtin twice. */
+ call1 = build_call_expr_loc (input_location, func, 1,
+ fold_convert (arg_type, arg));
+ arg2 = fold_build2_loc (input_location, RSHIFT_EXPR, utype, arg,
+ build_int_cst (utype, LONG_LONG_TYPE_SIZE));
+ call2 = build_call_expr_loc (input_location, func, 1,
+ fold_convert (arg_type, arg2));
+ se->expr = fold_build2_loc (input_location, PLUS_EXPR, result_type,
+ call1, call2);
+ return;
+ }
}
/* Convert the actual argument twice: first, to the unsigned type of the
