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| author | Alan Modra <amodra@gmail.com> | 2016-05-10 08:42:20 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gcc.gnu.org> | 2016-05-10 08:42:20 +0930 |
| commit | 5def232a0bf5d4c0e521f0d2e0516a14c46e6ee6 (patch) | |
| tree | 25e62a1bc9665831c988216d9f2a5cf946c4a32f /gcc | |
| parent | 9491d081fe34ea2706d922941840368401a155e2 (diff) | |
| download | gcc-5def232a0bf5d4c0e521f0d2e0516a14c46e6ee6.zip gcc-5def232a0bf5d4c0e521f0d2e0516a14c46e6ee6.tar.gz gcc-5def232a0bf5d4c0e521f0d2e0516a14c46e6ee6.tar.bz2 | |
[RS6000] Stop regrename twiddling with split-stack prologue
PR target/70947
* config/rs6000/rs6000.c (rs6000_expand_split_stack_prologue): Stop
regrename modifying insns saving lr before __morestack call.
* config/rs6000/rs6000.md (split_stack_return): Similarly for
insns restoring lr after __morestack call.
From-SVN: r236052
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/config/rs6000/rs6000.c | 5 | ||||
| -rw-r--r-- | gcc/config/rs6000/rs6000.md | 4 |
3 files changed, 16 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 42152ef..687ab97 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2016-05-10 Alan Modra <amodra@gmail.com> + + PR target/70947 + * config/rs6000/rs6000.c (rs6000_expand_split_stack_prologue): Stop + regrename modifying insns saving lr before __morestack call. + * config/rs6000/rs6000.md (split_stack_return): Similarly for + insns restoring lr after __morestack call. + 2016-05-09 Jakub Jelinek <jakub@redhat.com> * config/i386/i386.md (set_got, set_got_labelled, lwp_llwpcb, diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index 34495f3..007bf57 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -27993,6 +27993,11 @@ rs6000_expand_split_stack_prologue (void) const0_rtx, const0_rtx)); call_fusage = NULL_RTX; use_reg (&call_fusage, r12); + /* Say the call uses r0, even though it doesn't, to stop regrename + from twiddling with the insns saving lr, trashing args for cfun. + The insns restoring lr are similarly protected by making + split_stack_return use r0. */ + use_reg (&call_fusage, r0); add_function_usage_to (insn, call_fusage); emit_insn (gen_frame_load (r0, r1, info->lr_save_offset)); insn = emit_move_insn (lr, r0); diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index ed1989c..349bcca 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -12587,8 +12587,10 @@ (set_attr "indexed" "no")]) ;; A return instruction which the middle-end doesn't see. +;; Use r0 to stop regrename twiddling with lr restore insns emitted +;; after the call to __morestack. (define_insn "split_stack_return" - [(unspec_volatile [(const_int 0)] UNSPECV_SPLIT_STACK_RETURN)] + [(unspec_volatile [(use (reg:SI 0))] UNSPECV_SPLIT_STACK_RETURN)] "" "blr" [(set_attr "type" "jmpreg")]) |