From 672314026cf2b2b904a1a4ff3b5a38f2c637acbf Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Fri, 17 Mar 2000 19:35:44 +0000 Subject: [PATCH] Handle same-section relocations where the destination is at an address >= 0x00400000. --- gas/ChangeLog | 5 +++++ gas/config/tc-arm.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 59 insertions(+), 4 deletions(-) diff --git a/gas/ChangeLog b/gas/ChangeLog index 2b7a433..d259c7c 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,8 @@ +2000-03-17 Nick Clifton + + * config/tc-arm.c (md_apply_fix3): Handle same-section relocations + that have a destingation >= 0x400000. + Thu Mar 16 23:45:16 2000 J"orn Rennecke * config/tc-sh.c (md_begin): When encountering insn that are diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c index f8f43be..55cca9d 100644 --- a/gas/config/tc-arm.c +++ b/gas/config/tc-arm.c @@ -5560,13 +5560,63 @@ md_apply_fix3 (fixP, val, seg) case BFD_RELOC_ARM_PCREL_BRANCH: newval = md_chars_to_number (buf, INSN_SIZE); + /* Sign-extend a 24-bit number. */ +#define SEXT24(x) ((((x) & 0xffffff) ^ (~ 0x7fffff)) + 0x800000) + #ifdef OBJ_ELF if (! target_oabi) - value = fixP->fx_offset; + value = fixP->fx_offset; #endif - value = (value >> 2) & 0x00ffffff; - value = (value + (newval & 0x00ffffff)) & 0x00ffffff; - newval = value | (newval & 0xff000000); + + /* We are going to store value (shifted right by two) in the + instruction, in a 24 bit, signed field. Thus we need to check + that none of the top 8 bits of the shifted value (top 7 bits of + the unshifted, unsigned value) are set, or that they are all set. */ + if ((value & 0xfe000000UL) != 0 + && ((value & 0xfe000000UL) != 0xfe000000UL)) + { +#ifdef OBJ_ELF + /* Normally we would be stuck at this point, since we cannot store + the absolute address that is the destination of the branch in the + 24 bits of the branch instruction. If however, we happen to know + that the destination of the branch is in the same section as the + branch instruciton itself, then we can compute the relocation for + ourselves and not have to bother the linker with it. + + FIXME: The tests for OBJ_ELF and ! target_oabi are only here + because I have not worked out how to do this for OBJ_COFF or + target_oabi. */ + if (! target_oabi + && fixP->fx_addsy != NULL + && S_IS_DEFINED (fixP->fx_addsy) + && S_GET_SEGMENT (fixP->fx_addsy) == seg) + { + /* Get pc relative value to go into the branch. */ + value = * val; + + /* Permit a backward branch provided that enough bits are set. + Allow a forwards branch, provided that enough bits are clear. */ + if ((value & 0xfe000000UL) == 0xfe000000UL + || (value & 0xfe000000UL) == 0) + fixP->fx_done = 1; + } + + if (! fixP->fx_done) +#endif + as_bad_where (fixP->fx_file, fixP->fx_line, + _("gas can't handle same-section branch dest >= 0x04000000")); + } + + value >>= 2; + value += SEXT24 (newval); + + if ((value & 0xff000000UL) != 0 + && (fixP->fx_done == 0 + || ((value & 0xff000000UL) != 0xff000000UL))) + as_bad_where (fixP->fx_file, fixP->fx_line, + _("out of range branch")); + + newval = (value & 0x00ffffff) | (newval & 0xff000000); md_number_to_chars (buf, newval, INSN_SIZE); break; -- 2.7.4