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author | Alan Modra <amodra@gmail.com> | 2019-10-25 19:46:24 +1030 |
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committer | Alan Modra <amodra@gmail.com> | 2019-10-25 23:19:24 +1030 |
commit | 37a5888387413a4b787468eff710eefebe134201 (patch) | |
tree | 85003343520c718155045d0ea00437ef7b502930 | |
parent | 158da0d12a7c9bb01c6d9b8d3da609a1e2561916 (diff) | |
download | gdb-37a5888387413a4b787468eff710eefebe134201.zip gdb-37a5888387413a4b787468eff710eefebe134201.tar.gz gdb-37a5888387413a4b787468eff710eefebe134201.tar.bz2 |
PR25125, relaxation chooses wrong branch size
The patch I made for PR12049 didn't test for a "negative" branch
properly. "if (target < address)" ought to have been
"if (target < address + fragP->fr_fix)". Rather than making that
change, this patch adds fragP->fr_fix into address earlier. The patch
also avoids running into a bad interaction with the m68k
md_prepare_relax_scan by returning zero growth immediately, since the
adjusted target expression would result in a zero "aim".
PR gas/25125
PR gas/12049
* write.c (relax_frag): Correct calculation of delta for
positive branches where "stretch" would make the branch
negative. Return zero immediately in that case. Correct
TC_PCREL_ADJUST comment.
-rw-r--r-- | gas/ChangeLog | 9 | ||||
-rw-r--r-- | gas/write.c | 8 |
2 files changed, 13 insertions, 4 deletions
diff --git a/gas/ChangeLog b/gas/ChangeLog index ac2e3d7..8b78037 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,12 @@ +2019-10-25 Alan Modra <amodra@gmail.com> + + PR gas/25125 + PR gas/12049 + * write.c (relax_frag): Correct calculation of delta for + positive branches where "stretch" would make the branch + negative. Return zero immediately in that case. Correct + TC_PCREL_ADJUST comment. + 2019-10-16 Alan Modra <amodra@gmail.com> * config/tc-xtensa.c (xg_order_trampoline_chain_entry): Don't diff --git a/gas/write.c b/gas/write.c index 9b5ae6f..8f7786e 100644 --- a/gas/write.c +++ b/gas/write.c @@ -2497,7 +2497,7 @@ relax_frag (segT segment, fragS *fragP, long stretch) const relax_typeS *table; target = fragP->fr_offset; - address = fragP->fr_address; + address = fragP->fr_address + fragP->fr_fix; table = TC_GENERIC_RELAX_TABLE; this_state = fragP->fr_subtype; start_type = this_type = table + this_state; @@ -2537,13 +2537,13 @@ relax_frag (segT segment, fragS *fragP, long stretch) negative. Don't allow this in case the negative reach is large enough to require a larger branch instruction. */ else if (target < address) - target = fragP->fr_next->fr_address + stretch; + return 0; } } - aim = target - address - fragP->fr_fix; + aim = target - address; #ifdef TC_PCREL_ADJUST - /* Currently only the ns32k family needs this. */ + /* Currently only the ns32k and arc needs this. */ aim += TC_PCREL_ADJUST (fragP); #endif |