From a35ab1c1a3d04c28519a062fedfebda818b927a4 Mon Sep 17 00:00:00 2001 From: Tamar Christina Date: Mon, 2 Oct 2023 11:50:24 +0100 Subject: rtl: relax validate_subreg to allow paradoxical subregs that change mode This patch relaxes the subreg invariant that you can only change modes or make it paradoxical in one conversion. i.e. it now allows subreg:V2DI (reg:DF ..)) This is well defined in the generic sense and allowing it would enable you to write RTL without the extra moves which can be interfered with by combine. Patch has been pre-approved[1], but giving people chance to object [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629119.html gcc/ChangeLog: * emit-rtl.cc (validate_subreg): Relax subreg rule. --- gcc/emit-rtl.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'gcc/emit-rtl.cc') diff --git a/gcc/emit-rtl.cc b/gcc/emit-rtl.cc index 8bd623d..84b6833 100644 --- a/gcc/emit-rtl.cc +++ b/gcc/emit-rtl.cc @@ -947,7 +947,7 @@ validate_subreg (machine_mode omode, machine_mode imode, in post-reload splitters that make arbitrarily mode changes to the registers themselves. */ else if (VECTOR_MODE_P (omode) - && GET_MODE_INNER (omode) == GET_MODE_INNER (imode)) + && GET_MODE_UNIT_SIZE (omode) == GET_MODE_UNIT_SIZE (imode)) ; /* Subregs involving floating point modes are not allowed to change size unless it's an insert into a complex mode. -- cgit v1.1