Date: Fri, 28 Mar 2003 18:44:25 -0800 From: "David O'Brien" <obrien@FreeBSD.org> To: Thomas Moestl <tmoestl@gmx.net> Cc: Kris Kennaway <kris@obsecurity.org>, kan@FreeBSD.org, sparc64@FreeBSD.org Subject: Re: assembler error in XFree86 snapshot Message-ID: <20030329024425.GA87915@dragon.nuxi.com> In-Reply-To: <20030116201728.GA279@crow.dom2ip.de> References: <20030116072448.GA29468@rot13.obsecurity.org> <20030116201728.GA279@crow.dom2ip.de>
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This either needs to get properly reported back to the GCC guys thru
their GNATs system; or a patch needs to be made against the gcc33 or "top
of tree" sources. Otherwise there isn't much we can do about this.
On Thu, Jan 16, 2003 at 09:17:28PM +0100, Thomas Moestl wrote:
> On Wed, 2003/01/15 at 23:24:48 -0800, Kris Kennaway wrote:
> > I'm trying to compile anholt's XFree86 4.2.99 snapshot on sparc, and I
> > get the following error message:
> >
> > cc -c -O -pipe -ansi -Dasm=__asm -Wall -Wpointer-arith -Wundef -I/usr/tmp/XFree86-4-libraries-devel/work/xc -I/usr/tmp/XFree86-4-libraries-devel/work/xc/exports/include -DCSRG_BASED -DFUNCPROTO=15 -DNARROWPROTO -DXTHREADS -D_REENTRANT -D_THREAD_SAFE -DXUSE_MTSAFE_API -DXNO_MTSAFE_PWDAPI -DMALLOC_0_RETURNS_NULL XRes.c
> > {standard input}: Assembler messages:
> > {standard input}:667: Error: relocation overflow
> > *** Error code 1
> >
> > line 667 of the .s file is:
> >
> > > .LL86:
> > > umul %o0, 4294967295, %o0
>
> This is a arguably a gcc bug. All (13-bit) immediate operands are
> sign-extended, even those to instructions which operate on unsigned
> values, so umul can handle a range of very small and a range of very
> large operands. gcc correctly recognizes that it can use an immediate
> here; however, it chooses to output it as an unsigned number and does
> not sign-extended it from 32 to 64 bit.
>
> All sign extensions for instructions are made to the full 64 bit
> however (even if umul only happens to use 32 of those), so when the
> assembler checks whether a value is representable as an immediate, it
> will check that the 64-bit sign extension of the immediate creates
> the desired value (in sparc64 mode), i.e. it doesn't ignore the upper
> 32 bits even if a particular instruction does not use them.
>
> One solution is to generate negative literals for immediates if we
> mean them to be sign-extended (which gcc does already for some other
> instructions). The attached patch implements this, I'm not sure it
> uses the best possible way to do this though, and it also needs a bit
> more testing.
>
> - Thomas
>
> --
> Thomas Moestl <tmoestl@gmx.net> http://www.tu-bs.de/~y0015675/
> <tmm@FreeBSD.org> http://people.FreeBSD.org/~tmm/
> PGP fingerprint: 1C97 A604 2BD0 E492 51D0 9C0F 1FE6 4F1D 419C 776C
>
> Index: config/sparc/sparc.c
> ===================================================================
> RCS file: /ncvs/src/contrib/gcc/config/sparc/sparc.c,v
> retrieving revision 1.1.1.9
> diff -u -r1.1.1.9 sparc.c
> --- config/sparc/sparc.c 10 Oct 2002 04:40:04 -0000 1.1.1.9
> +++ config/sparc/sparc.c 16 Jan 2003 18:09:06 -0000
> @@ -6462,6 +6462,22 @@
> output_address (XEXP (x, 0));
> return;
>
> + case 's':
> + {
> + /* Print a sign-extended 32-bit value. */
> + HOST_WIDE_INT xi;
> + int i;
> + if (GET_CODE(x) == CONST_INT)
> + xi = INTVAL (x);
> + else if (GET_CODE(x) == CONST_DOUBLE)
> + xi = CONST_DOUBLE_LOW (x);
> + else
> + output_operand_lossage ("invalid %%s operand");
> + i = trunc_int_for_mode (xi, SImode);
> + fprintf (file, "%d", i);
> + return;
> + }
> +
> case 0:
> /* Do nothing special. */
> break;
> Index: config/sparc/sparc.md
> ===================================================================
> RCS file: /ncvs/src/contrib/gcc/config/sparc/sparc.md,v
> retrieving revision 1.1.1.8
> diff -u -r1.1.1.8 sparc.md
> --- config/sparc/sparc.md 10 Oct 2002 04:40:08 -0000 1.1.1.8
> +++ config/sparc/sparc.md 16 Jan 2003 17:09:36 -0000
> @@ -6120,7 +6120,7 @@
> "TARGET_HARD_MUL32"
> "*
> {
> - return TARGET_SPARCLET ? \"umuld\\t%1, %2, %L0\" : \"umul\\t%1, %2, %L0\\n\\trd\\t%%y, %H0\";
> + return TARGET_SPARCLET ? \"umuld\\t%1, %s2, %L0\" : \"umul\\t%1, %s2, %L0\\n\\trd\\t%%y, %H0\";
> }"
> [(set (attr "type")
> (if_then_else (eq_attr "isa" "sparclet")
> @@ -6134,7 +6134,7 @@
> (mult:DI (zero_extend:DI (match_operand:SI 1 "register_operand" "r"))
> (match_operand:SI 2 "uns_small_int" "")))]
> "TARGET_DEPRECATED_V8_INSNS && TARGET_ARCH64"
> - "umul\\t%1, %2, %0"
> + "umul\\t%1, %s2, %0"
> [(set_attr "type" "imul")])
>
> ;; XXX
> @@ -6145,8 +6145,8 @@
> (clobber (match_scratch:SI 3 "=X,h"))]
> "TARGET_V8PLUS"
> "@
> - umul\\t%1, %2, %L0\\n\\tsrlx\\t%L0, 32, %H0
> - umul\\t%1, %2, %3\\n\\tsrlx\\t%3, 32, %H0\\n\\tmov\\t%3, %L0"
> + umul\\t%1, %s2, %L0\\n\\tsrlx\\t%L0, 32, %H0
> + umul\\t%1, %s2, %3\\n\\tsrlx\\t%3, 32, %H0\\n\\tmov\\t%3, %L0"
> [(set_attr "type" "multi")
> (set_attr "length" "2,3")])
>
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