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authorKevin Buettner <kevinb@redhat.com>2007-07-14 00:15:50 +0000
committerKevin Buettner <kevinb@redhat.com>2007-07-14 00:15:50 +0000
commitfc565b9d6c4cf66c5056abf526ba8da1a24aaa02 (patch)
tree1df7b2ce34bbde9d0af0863553a4b195a81a5a3c /gdb/mep-tdep.c
parentb3a37c9a6432e71a965788fd802d7a96f525140f (diff)
downloadgdb-fc565b9d6c4cf66c5056abf526ba8da1a24aaa02.tar.gz
* mep-tdep.c (mep_analyze_prologue): Update comment for BRA
instruction case.
Diffstat (limited to 'gdb/mep-tdep.c')
-rw-r--r--gdb/mep-tdep.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/gdb/mep-tdep.c b/gdb/mep-tdep.c
index 5d604378d82..01baab3700a 100644
--- a/gdb/mep-tdep.c
+++ b/gdb/mep-tdep.c
@@ -1812,13 +1812,24 @@ mep_analyze_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc,
}
else if (IS_BRA (insn) && BRA_DISP (insn) > 0)
{
- /* When a loop appears as the first statement as a function
+ /* When a loop appears as the first statement of a function
body, gcc 4.x will use a BRA instruction to branch to the
loop condition checking code. This BRA instruction is
marked as part of the prologue. We therefore set next_pc
to this branch target and also stop the prologue scan.
The instructions at and beyond the branch target should
- no longer be associated with the prologue. */
+ no longer be associated with the prologue.
+
+ Note that we only consider forward branches here. We
+ presume that a forward branch is being used to skip over
+ a loop body.
+
+ A backwards branch is covered by the default case below.
+ If we were to encounter a backwards branch, that would
+ most likely mean that we've scanned through a loop body.
+ We definitely want to stop the prologue scan when this
+ happens and that is precisely what is done by the default
+ case below. */
next_pc = pc + BRA_DISP (insn);
after_last_frame_setup_insn = next_pc;
break;