Sam James <s...@gentoo.org> writes:
> John David Anglin <dave.ang...@bell.net> writes: > >> On 2023-11-16 4:52 p.m., Jeff Law wrote: >>> >>> >>> On 11/16/23 10:54, John David Anglin wrote: >>>> Tested on hppa-unknown-linux-gnu and hppa64-hp-hpux11.11. Committed >>>> to trunk. >>>> >>>> This patch works around problem compiling python3.11 by improving >>>> REG+D address handling. The change results in smaller code and >>>> reduced register pressure. >>>> >>>> Dave >>>> --- >>>> >>>> hppa: Revise REG+D address support to allow long displacements before >>>> reload >>>> >>>> In analyzing PR rtl-optimization/112415, I realized that restricting >>>> REG+D offsets to 5-bits before reload results in very poor code and >>>> complexities in optimizing these instructions after reload. The >>>> general problem is long displacements are not allowed for floating >>>> point accesses when generating PA 1.1 code. Even with PA 2.0, there >>>> is a ELF linker bug that prevents using long displacements for >>>> floating point loads and stores. >>>> >>>> In the past, enabling long displacements before reload caused issues >>>> in reload. However, there have been fixes in the handling of reloads >>>> for floating-point accesses. This change allows long displacements >>>> before reload and corrects a couple of issues in the constraint >>>> handling for integer and floating-point accesses. >>>> >>>> 2023-11-16 John David Anglin <dang...@gcc.gnu.org> >>>> >>>> gcc/ChangeLog: >>>> >>>> PR rtl-optimization/112415 >>>> * config/pa/pa.cc (pa_legitimate_address_p): Allow 14-bit >>>> displacements before reload. Simplify logic flow. Revise >>>> comments. >>>> * config/pa/pa.h (TARGET_ELF64): New define. >>>> (INT14_OK_STRICT): Update define and comment. >>>> * config/pa/pa64-linux.h (TARGET_ELF64): Define. >>>> * config/pa/predicates.md (base14_operand): Don't check >>>> alignment of short displacements. >>>> (integer_store_memory_operand): Don't return true when >>>> reload_in_progress is true. Remove INT_5_BITS check. >>>> (floating_point_store_memory_operand): Don't return true when >>>> reload_in_progress is true. Use INT14_OK_STRICT to check >>>> whether long displacements are always okay. >>> I strongly suspect this is going to cause problems in the end. >>> >>> I've already done what you're trying to do. It'll likely look fine >>> for an extended period of time, but it will almost certainly break >>> one day. > > Jeff, I don't suppose you could dig out the old bugs/commits just out of > interest? > >> I could happen. If it happens and can't be fixed, it's easy enough to >> return false in >> pa_legitimate_address_p before reload. Maybe we could add an optimization >> option for this. I might hack in an option for local testing so I can quickly check with/without... >> >> As it stands, the code improvement for python is significant. I don't think >> f-m-o can fix things after reload. >>a >> Hopefully, Sam will test the change with various package builds on gentoo. >> Debian is still on gcc-13. > > Yeah, happy to do that. We haven't got GCC 14 deployed in the wild, but > we have it available for people who want to test and opt-in to it. > > Fingers crossed it's calm. I'll let you know if it isn't ;) > >> I'm not seeing any obvious problems in the gcc testsuite. It needs testing >> on packages that do extensive >> floating point calculations. > > OK, I'll focus on those. > >> >> Dave
