From: Kirill A. Korinsky <kirill@korins.ky>
Subject: Re: llvm SparcAsmParser off by one
To: Mark Kettenis <mark.kettenis@xs4all.nl>
Cc: Theo Buehler <tb@theobuehler.org>, tech@openbsd.org
Date: Fri, 21 Aug 2026 14:26:25 +0200

On Fri, 21 Aug 2026 13:00:10 +0200,
Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
> 
> > Date: Fri, 21 Aug 2026 09:06:58 +0200
> > From: Theo Buehler <tb@theobuehler.org>
> > 
> > The build of lang/rust on sparc64 with llvm errors out:
> > 
> > warning: psm@0.1.26: src/arch/sparc64.s:59:26: error: invalid register name
> > warning: psm@0.1.26:     .cfi_register %r15, %r31
> > warning: psm@0.1.26:                          ^
> > error: failed to run custom build command for `psm v0.1.26`
> > 
> > This is because of an off by one rejecting %r31. Not sure if this or
> > <= 31 would be preferred. I'll sync this to ports of course.
> > 
> > diff --git a/gnu/llvm/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp b/gnu/llvm/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
> > index e5c7fa86b3..a9fa9ba769 100644
> > --- a/gnu/llvm/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
> > +++ b/gnu/llvm/llvm/lib/Target/Sparc/AsmParser/SparcAsmParser.cpp
> > @@ -1614,7 +1614,7 @@
> >    // %r0 - %r31
> >    int64_t RegNo = 0;
> >    if (Name.starts_with_insensitive("r") &&
> > -      !Name.substr(1, 2).getAsInteger(10, RegNo) && RegNo < 31) {
> > +      !Name.substr(1, 2).getAsInteger(10, RegNo) && RegNo < 32) {
> >      RegKind = SparcOperand::rk_IntReg;
> >      return IntRegs[RegNo];
> >    }
> > 
> 
> I'd probably have used <= 31 given the code in MorphToIntPairReg(),
> but either way, ok kettenis@
> 

Yes, I think it is a typo <= -> <

Also, I think it need to be upstreamed

Anyway OK kirill@

-- 
wbr, Kirill