diff options
| author |   miod <miod@openbsd.org> | 2012-11-15 21:48:15 +0000 |
|---|---|---|
| committer | miod <miod@openbsd.org> | 2012-11-15 21:48:15 +0000 |
| commit | ff385ce478f0d42146acbb1036ae30279941e715 (patch) | |
| tree | d6cec5260bae39b69546bc539378651d7ba6738d | |
| parent | Make this cross-compile friendly by defining ATTRIBUTE_UNUSED to an empty (diff) | |
| download | wireguard-openbsd-ff385ce478f0d42146acbb1036ae30279941e715.tar.xz wireguard-openbsd-ff385ce478f0d42146acbb1036ae30279941e715.zip | |
Only allow the "return" insn construct (which simply yields a "jmp r1" line)
if null_prologue(), i.e. if there is no stack frame to undo and no r1 to
restore.
Make the "epilogue" insn construct no longer depend on "return", but rather
on "(use (const_int 0))" as "prologue" and as generally done on other backends.
On the other hand, make it unconditionnal, instead of "! null_prologue()".
These changes make sure than a leaf procedure call does not end up "returning"
(i.e. jmp r1) upon return from the call, without restoring r1 and r30 (whenever
applicable) from the existing stack frame.
This makes a gcc3-compiled __main() (from libgcc2.c) no longer spin after
invoking the constructors, and gives the real payload (i.e. main() and whatever
follows from there) a chance to run.
| -rw-r--r-- | gnu/usr.bin/gcc/gcc/config/m88k/m88k.md | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/gnu/usr.bin/gcc/gcc/config/m88k/m88k.md b/gnu/usr.bin/gcc/gcc/config/m88k/m88k.md index a79cce0778c..7b2d6905984 100644 --- a/gnu/usr.bin/gcc/gcc/config/m88k/m88k.md +++ b/gnu/usr.bin/gcc/gcc/config/m88k/m88k.md @@ -4001,18 +4001,18 @@ (define_insn "return" [(return)] - "reload_completed" + "null_prologue()" "jmp%. %#r1" [(set_attr "type" "jump")]) (define_expand "prologue" - [(const_int 0)] + [(use (const_int 0))] "" "m88k_expand_prologue (); DONE;") (define_expand "epilogue" - [(return)] - "! null_prologue ()" + [(use (const_int 0))] + "" "m88k_expand_epilogue ();") (define_insn "blockage" |