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author | Kevin Buettner <kevinb@redhat.com> | 2007-07-14 00:15:50 +0000 |
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committer | Kevin Buettner <kevinb@redhat.com> | 2007-07-14 00:15:50 +0000 |
commit | fc565b9d6c4cf66c5056abf526ba8da1a24aaa02 (patch) | |
tree | 1df7b2ce34bbde9d0af0863553a4b195a81a5a3c /gdb/mep-tdep.c | |
parent | b3a37c9a6432e71a965788fd802d7a96f525140f (diff) | |
download | gdb-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.c | 15 |
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; |