On 1/9/2026 3:08 PM, Jakub Jelinek wrote:
On Thu, Jan 08, 2026 at 08:50:35AM -0700, Jeffrey Law wrote:
+bool
+riscv_bitint_type_info (int n, struct bitint_info *info)
+{
+ if (n <= 8)
+ info->limb_mode = QImode;
+ else if (n <= 16)
+ info->limb_mode = HImode;
+ else if (n <= 32)
+ info->limb_mode = SImode;
+ else if (n <= 64)
+ info->limb_mode = DImode;
+ else if (n <= 128 && TARGET_64BIT)
+ info->limb_mode = TImode;
+ else
+ info->limb_mode = TARGET_64BIT ? DImode : SImode;
So I've never looked at how BitInt works, so if this is totally off-base
just say so ;-)
It seems a bit odd to have the limb_mode by DImode for rv32 when we don't
have any DImode operations in rv32. Though we allow TImode for rv64, so
perhaps we're just relying on widening capabilities in the expander
interfaces under the hood?
It also seems a bit odd that for n > 128 and TARGET_64BIT that we select
DImode when we use TImode for sizes > 64, but <= 128. Similarly for
!TARGET_64BIT we have SImode and DImode respectively.
It depends on what the psABI says (if it says anything at all).
What Kito posted is quite usual thing (except for the abi_limb_mode !=
limb_mode && extended = true case which still needs to have a few spots
in the generic handling tweaked (like for arm32).
Thanks for the clarification. It just looked odd, my comments weren't
based on knowing anything at all about how this stuff works.
Kito -- I think this should go forward ASAP to get as much soak time as
possible.
jeff
