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Re: [mips patch RFC] removal of gas embedded-pic support code
- From: David Ung <davidu at mips dot com>
- To: cgd at broadcom dot com, ica2_ts at csv dot ica dot uni-stuttgart dot de, binutils at sources dot redhat dot com
- Date: Wed, 05 May 2004 18:44:40 +0100
- Subject: Re: [mips patch RFC] removal of gas embedded-pic support code
- Organization: MIPS Technologies UK
>At Thu, 29 Apr 2004 02:46:46 +0000 (UTC), "Thiemo Seufer" wrote:
>> I think it is ok.
>
>Thanks for looking it over.
>
>I've checked it in. I *really* hope it really doesn't break
>anything. 8-)
>
>
>chris
Chris,
woops. your recent patch seem to have broke building of the compiler on
linux. The problem occurs when building for libgcc/./_divdi3.o
gas fails with:
Error: operation combines symbols in different segments
as it is trying to assemble this piece of .s code generated from gcc.
.section .eh_frame,"aw",@progbits
$Lframe1:
.4byte $LECIE1-$LSCIE1
$LSCIE1:
.4byte 0x0
.byte 0x1
.ascii "zR\000"
.uleb128 0x1
.sleb128 4
.byte 0x1f
.uleb128 0x1
.byte 0x1b
.byte 0xc
.uleb128 0x1d
.uleb128 0x0
.align 2
$LECIE1:
$LSFDE1:
.4byte $LEFDE1-$LASFDE1
$LASFDE1:
.4byte $LASFDE1-$Lframe1
.4byte $LFB42-. **
.4byte $LFE42-$LFB42
.uleb128 0x0
** $LFB42 is from the text section of divdi3.
I've reverted back the necessary changes to your patch, so that it now
works with the above.
David.
Index: bfd/ChangeLog
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/bfd/ChangeLog,v
retrieving revision 1.2535
diff -u -r1.2535 ChangeLog
--- bfd/ChangeLog 3 May 2004 14:52:01 -0000 1.2535
+++ bfd/ChangeLog 5 May 2004 17:38:51 -0000
@@ -1,3 +1,15 @@
+2004-05-05 David Ung <davidu@mips.com>
+
+ * elfxx-mips.c (mips_elf_calculate_relocation): Put back cases for
+ R_MIPS_PC32 and R_MIPS_PC64.
+
+ * elf32-mips.c: Put back elf_mips_gnu_pcrel64 and
+ elf_mips_gnu_pcrel32.
+ (bfd_elf32_bfd_reloc_type_lookup): Put back cases for
+ BFD_RELOC_64_PCREL and BFD_RELOC_32_PCREL.
+ (mips_elf32_rtype_to_howto): Put back cases for R_MIPS_PC32 and
+ R_MIPS_PC64.
+
2004-05-03 Alan Modra <amodra@bigpond.net.au>
* elf.c (_bfd_elf_rela_local_sym): Set kept_section for excluded
Index: bfd/elf32-mips.c
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/bfd/elf32-mips.c,v
retrieving revision 1.175
diff -u -r1.175 elf32-mips.c
--- bfd/elf32-mips.c 24 Apr 2004 22:07:13 -0000 1.175
+++ bfd/elf32-mips.c 5 May 2004 17:38:51 -0000
@@ -615,6 +615,38 @@
0xffff, /* dst_mask */
TRUE); /* pcrel_offset */
+/* 64 bit pc-relative. */
+static reloc_howto_type elf_mips_gnu_pcrel64 =
+ HOWTO (R_MIPS_PC64, /* type */
+ 0, /* rightshift */
+ 4, /* size (0 = byte, 1 = short, 2 = long) */
+ 64, /* bitsize */
+ TRUE, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_signed, /* complain_on_overflow */
+ _bfd_mips_elf_generic_reloc, /* special_function */
+ "R_MIPS_PC64", /* name */
+ TRUE, /* partial_inplace */
+ MINUS_ONE, /* src_mask */
+ MINUS_ONE, /* dst_mask */
+ TRUE); /* pcrel_offset */
+
+/* 32 bit pc-relative. */
+static reloc_howto_type elf_mips_gnu_pcrel32 =
+ HOWTO (R_MIPS_PC32, /* type */
+ 0, /* rightshift */
+ 2, /* size (0 = byte, 1 = short, 2 = long) */
+ 32, /* bitsize */
+ TRUE, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_signed, /* complain_on_overflow */
+ _bfd_mips_elf_generic_reloc, /* special_function */
+ "R_MIPS_PC32", /* name */
+ TRUE, /* partial_inplace */
+ 0xffffffff, /* src_mask */
+ 0xffffffff, /* dst_mask */
+ TRUE); /* pcrel_offset */
+
/* GNU extension to record C++ vtable hierarchy */
static reloc_howto_type elf_mips_gnu_vtinherit_howto =
HOWTO (R_MIPS_GNU_VTINHERIT, /* type */
@@ -1071,6 +1103,10 @@
return &elf_mips_gnu_vtentry_howto;
case BFD_RELOC_16_PCREL_S2:
return &elf_mips_gnu_rel16_s2;
+ case BFD_RELOC_64_PCREL:
+ return &elf_mips_gnu_pcrel64;
+ case BFD_RELOC_32_PCREL:
+ return &elf_mips_gnu_pcrel32;
}
}
@@ -1092,6 +1128,10 @@
return &elf_mips_gnu_vtentry_howto;
case R_MIPS_GNU_REL16_S2:
return &elf_mips_gnu_rel16_s2;
+ case R_MIPS_PC64:
+ return &elf_mips_gnu_pcrel64;
+ case R_MIPS_PC32:
+ return &elf_mips_gnu_pcrel32;
default:
BFD_ASSERT (r_type < (unsigned int) R_MIPS_max);
return &elf_mips_howto_table_rel[r_type];
Index: bfd/elfxx-mips.c
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/bfd/elfxx-mips.c,v
retrieving revision 1.100
diff -u -r1.100 elfxx-mips.c
--- bfd/elfxx-mips.c 24 Apr 2004 22:07:13 -0000 1.100
+++ bfd/elfxx-mips.c 5 May 2004 17:38:51 -0000
@@ -3335,6 +3335,12 @@
value &= howto->dst_mask;
break;
+ case R_MIPS_PC32:
+ case R_MIPS_PC64:
+ value = symbol + addend - p;
+ value &= howto->dst_mask;
+ break;
+
case R_MIPS_GNU_REL16_S2:
value = symbol + _bfd_mips_elf_sign_extend (addend, 18) - p;
overflowed_p = mips_elf_overflow_p (value, 18);
Index: gas/ChangeLog
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/gas/ChangeLog,v
retrieving revision 1.2114
diff -u -r1.2114 ChangeLog
--- gas/ChangeLog 29 Apr 2004 05:14:20 -0000 1.2114
+++ gas/ChangeLog 5 May 2004 17:38:51 -0000
@@ -1,3 +1,9 @@
+2004-05-05 David Ung <davidu@mips.com>
+
+ * config/tc-mips.c (md_apply_fix3): Revert last change.
+ (tc_gen_reloc): Put back pc rel handling.
+ * config/tc-mips.h: Defines DIFF_EXPR_OK.
+
2004-04-28 Chris Demetriou <cgd@broadcom.com>
* config/tc-mips.c (HAVE_32BIT_ADDRESSES, append_insn, macro_build)
Index: gas/config/tc-mips.c
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/gas/config/tc-mips.c,v
retrieving revision 1.263
diff -u -r1.263 tc-mips.c
--- gas/config/tc-mips.c 29 Apr 2004 05:14:21 -0000 1.263
+++ gas/config/tc-mips.c 5 May 2004 17:38:51 -0000
@@ -10861,8 +10861,7 @@
buf = (bfd_byte *) (fixP->fx_frag->fr_literal + fixP->fx_where);
/* We are not done if this is a composite relocation to set up gp.
*/
- assert (! fixP->fx_pcrel);
- if (fixP->fx_addsy == NULL
+ if (fixP->fx_addsy == NULL && ! fixP->fx_pcrel
&& !(fixP->fx_r_type == BFD_RELOC_MIPS_SUB
|| (fixP->fx_r_type == BFD_RELOC_64
&& (previous_fx_r_type == BFD_RELOC_GPREL32
@@ -12723,8 +12722,27 @@
*reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
- assert (! fixp->fx_pcrel);
- reloc->addend = fixp->fx_addnumber;
+ if (fixp->fx_pcrel)
+ {
+ bfd_vma pcrel_address;
+
+ pcrel_address = reloc->address;
+
+ if (OUTPUT_FLAVOR == bfd_target_elf_flavour)
+ {
+ /* At this point, fx_addnumber is "symbol offset - pcrel_address".
+ Relocations want only the symbol offset. */
+ reloc->addend = fixp->fx_addnumber + pcrel_address;
+ }
+ else
+ {
+ /* A gruesome hack which is a result of the gruesome gas reloc
+ handling. */
+ reloc->addend = pcrel_address;
+ }
+ }
+ else
+ reloc->addend = fixp->fx_addnumber;
/* Since the old MIPS ELF ABI uses Rel instead of Rela, encode the
vtable
entry to be used in the relocation's section offset. */
@@ -12735,6 +12753,34 @@
}
code = fixp->fx_r_type;
+ if (fixp->fx_pcrel)
+ {
+ switch (code)
+ {
+ case BFD_RELOC_8:
+ code = BFD_RELOC_8_PCREL;
+ break;
+ case BFD_RELOC_16:
+ code = BFD_RELOC_16_PCREL;
+ break;
+ case BFD_RELOC_32:
+ code = BFD_RELOC_32_PCREL;
+ break;
+ case BFD_RELOC_64:
+ code = BFD_RELOC_64_PCREL;
+ break;
+ case BFD_RELOC_8_PCREL:
+ case BFD_RELOC_16_PCREL:
+ case BFD_RELOC_32_PCREL:
+ case BFD_RELOC_64_PCREL:
+ case BFD_RELOC_16_PCREL_S2:
+ break;
+ default:
+ as_bad_where (fixp->fx_file, fixp->fx_line,
+ _("Cannot make %s relocation PC relative"),
+ bfd_get_reloc_code_name (code));
+ }
+ }
/* To support a PC relative reloc, we used a Cygnus extension.
We check for that here to make sure that we don't let such a
Index: gas/config/tc-mips.h
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/gas/config/tc-mips.h,v
retrieving revision 1.35
diff -u -r1.35 tc-mips.h
--- gas/config/tc-mips.h 29 Apr 2004 05:14:22 -0000 1.35
+++ gas/config/tc-mips.h 5 May 2004 17:38:51 -0000
@@ -58,6 +58,10 @@
#define MAX_MEM_FOR_RS_ALIGN_CODE (1 + 2)
+/* We permit PC relative difference expressions when generating
+ embedded PIC code. */
+#define DIFF_EXPR_OK
+
/* Tell assembler that we have an itbl_mips.h header file to include.
*/
#define HAVE_ITBL_CPU
Index: include/elf/ChangeLog
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/include/elf/ChangeLog,v
retrieving revision 1.205
diff -u -r1.205 ChangeLog
--- include/elf/ChangeLog 24 Apr 2004 22:07:14 -0000 1.205
+++ include/elf/ChangeLog 5 May 2004 17:38:51 -0000
@@ -1,3 +1,7 @@
+2004-05-05 David Ung <davidu@mips.com>
+
+ * mips.h: Put back R_MIPS_PC32 and R_MIPS_PC64.
+
2004-04-24 Chris Demetriou <cgd@broadcom.com>
* mips.h (R_MIPS_PC32, R_MIPS_PC64, R_MIPS_GNU_REL_LO16)
Index: include/elf/mips.h
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/include/elf/mips.h,v
retrieving revision 1.22
diff -u -r1.22 mips.h
--- include/elf/mips.h 24 Apr 2004 22:07:14 -0000 1.22
+++ include/elf/mips.h 5 May 2004 17:38:51 -0000
@@ -76,6 +76,8 @@
/* These relocs are used for the mips16. */
RELOC_NUMBER (R_MIPS16_26, 100)
RELOC_NUMBER (R_MIPS16_GPREL, 101)
+ RELOC_NUMBER (R_MIPS_PC32, 248)
+ RELOC_NUMBER (R_MIPS_PC64, 249)
/* FIXME: this relocation is used internally by gas. */
RELOC_NUMBER (R_MIPS_GNU_REL16_S2, 250)
/* These are GNU extensions to enable C++ vtable garbage collection.
*/
Index: rda/lib/gdbserv-state.c
===================================================================
RCS file: /cvsroot/gcc/src-cvs/src/rda/lib/gdbserv-state.c,v
retrieving revision 1.2
diff -u -r1.2 gdbserv-state.c
--- rda/lib/gdbserv-state.c 16 Jan 2003 17:28:33 -0000 1.2
+++ rda/lib/gdbserv-state.c 5 May 2004 17:38:52 -0000
@@ -165,6 +165,7 @@
same time as it stops itself */
break;
default:
+ break;
}
}
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