Re: [PATCH v2] gcc: backport tow patches to fix ICE in dwarf2out_var_location

["Peter A. Bigot" <pab@pabigot.com>]

On 10/31/2014 09:41 AM, jackie.huang@windriver.com wrote:
> From: Jackie Huang <jackie.huang@windriver.com>
>
> The first patch fixes the ICE in dwarf2out_var_location, at
> dwarf2out.c.
>
> r212171:
>      * except.c (emit_note_eh_region_end): New helper function.
>      (convert_to_eh_region_ranges): Use emit_note_eh_region_end to
>      emit EH_REGION_END note.
>      * jump.c (cleanup_barriers): Do not split a call and its
>      corresponding CALL_ARG_LOCATION note.
>
> But it introduced a regression issue:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63348
>
> so backport the fix for the regression as well:
>
> r215613:
>      PR rtl-optimization/63348
>      * emit-rtl.c (try_split): Do not emit extra barrier.

Thank you; this level of information makes it much easier to see where 
the things came from and avoid carrying a non-standard patch forward 
into arbitrary future versions of gcc.

Acked-by: Peter A. Bigot <pab@pabigot.com>

Peter

>
> Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
> ---
>   meta/recipes-devtools/gcc/gcc-4.9.inc              |   2 +
>   .../gcc/gcc-4.9/0058-gcc-r212171.patch             | 113 +++++++++++++++++++++
>   .../0059-gcc-PR-rtl-optimization-63348.patch       |  59 +++++++++++
>   3 files changed, 174 insertions(+)
>   create mode 100644 meta/recipes-devtools/gcc/gcc-4.9/0058-gcc-r212171.patch
>   create mode 100644 meta/recipes-devtools/gcc/gcc-4.9/0059-gcc-PR-rtl-optimization-63348.patch
>
> diff --git a/meta/recipes-devtools/gcc/gcc-4.9.inc b/meta/recipes-devtools/gcc/gcc-4.9.inc
> index 9a66cd2..8769128 100644
> --- a/meta/recipes-devtools/gcc/gcc-4.9.inc
> +++ b/meta/recipes-devtools/gcc/gcc-4.9.inc
> @@ -71,6 +71,8 @@ SRC_URI = "\
>       file://0054-gcc-Makefile.in-fix-parallel-building-failure.patch \
>       file://0055-PR-rtl-optimization-61801.patch \
>       file://0056-top-level-reorder_gcc-bug-61144.patch \
> +    file://0058-gcc-r212171.patch \
> +    file://0059-gcc-PR-rtl-optimization-63348.patch \
>   "
>   SRC_URI[md5sum] = "fddf71348546af523353bd43d34919c1"
>   SRC_URI[sha256sum] = "d334781a124ada6f38e63b545e2a3b8c2183049515a1abab6d513f109f1d717e"
> diff --git a/meta/recipes-devtools/gcc/gcc-4.9/0058-gcc-r212171.patch b/meta/recipes-devtools/gcc/gcc-4.9/0058-gcc-r212171.patch
> new file mode 100644
> index 0000000..4b312d4
> --- /dev/null
> +++ b/meta/recipes-devtools/gcc/gcc-4.9/0058-gcc-r212171.patch
> @@ -0,0 +1,113 @@
> +From ca03cf1b133d66eb978c68f6dbc345e9aabcba88 Mon Sep 17 00:00:00 2001
> +From: uros <uros@138bc75d-0d04-0410-961f-82ee72b054a4>
> +Date: Mon, 30 Jun 2014 19:30:52 +0000
> +Subject: [PATCH] r212171
> +
> +* except.c (emit_note_eh_region_end): New helper
> + function. 	(convert_to_eh_region_ranges): Use
> + emit_note_eh_region_end to 	emit EH_REGION_END note.
> + * jump.c (cleanup_barriers): Do not split a call and its
> + corresponding CALL_ARG_LOCATION note.
> +
> +git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@212171 138bc75d-0d04-0410-961f-82ee72b054a4
> +
> +Upstream-status: Backport [https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=212171]
> +Signed-off-by: Baoshan Pang <baoshan.pang@windriver.com>
> +---
> + gcc/except.c |   23 ++++++++++++++++++-----
> + gcc/jump.c   |   19 +++++++++++++++----
> + 2 files changed, 33 insertions(+), 9 deletions(-)
> +
> +diff --git a/gcc/except.c b/gcc/except.c
> +index dc5c1d2..7ac114f 100644
> +--- a/gcc/except.c
> ++++ b/gcc/except.c
> +@@ -2466,6 +2466,20 @@ add_call_site (rtx landing_pad, int action, int section)
> +   return call_site_base + crtl->eh.call_site_record_v[section]->length () - 1;
> + }
> +
> ++static rtx
> ++emit_note_eh_region_end (rtx insn)
> ++{
> ++  rtx next = NEXT_INSN (insn);
> ++
> ++  /* Make sure we do not split a call and its corresponding
> ++     CALL_ARG_LOCATION note.  */
> ++  if (next && NOTE_P (next)
> ++      && NOTE_KIND (next) == NOTE_INSN_CALL_ARG_LOCATION)
> ++    insn = next;
> ++
> ++  return emit_note_after (NOTE_INSN_EH_REGION_END, insn);
> ++}
> ++
> + /* Turn REG_EH_REGION notes back into NOTE_INSN_EH_REGION notes.
> +    The new note numbers will not refer to region numbers, but
> +    instead to call site entries.  */
> +@@ -2544,8 +2558,8 @@ convert_to_eh_region_ranges (void)
> + 		note = emit_note_before (NOTE_INSN_EH_REGION_BEG,
> + 					 first_no_action_insn_before_switch);
> + 		NOTE_EH_HANDLER (note) = call_site;
> +-		note = emit_note_after (NOTE_INSN_EH_REGION_END,
> +-					last_no_action_insn_before_switch);
> ++		note
> ++		  = emit_note_eh_region_end (last_no_action_insn_before_switch);
> + 		NOTE_EH_HANDLER (note) = call_site;
> + 		gcc_assert (last_action != -3
> + 			    || (last_action_insn
> +@@ -2569,8 +2583,7 @@ convert_to_eh_region_ranges (void)
> + 		    first_no_action_insn = NULL_RTX;
> + 		  }
> +
> +-		note = emit_note_after (NOTE_INSN_EH_REGION_END,
> +-					last_action_insn);
> ++		note = emit_note_eh_region_end (last_action_insn);
> + 		NOTE_EH_HANDLER (note) = call_site;
> + 	      }
> +
> +@@ -2617,7 +2630,7 @@ convert_to_eh_region_ranges (void)
> +
> +   if (last_action >= -1 && ! first_no_action_insn)
> +     {
> +-      note = emit_note_after (NOTE_INSN_EH_REGION_END, last_action_insn);
> ++      note = emit_note_eh_region_end (last_action_insn);
> +       NOTE_EH_HANDLER (note) = call_site;
> +     }
> +
> +diff --git a/gcc/jump.c b/gcc/jump.c
> +index 9418f65..a5e5f52 100644
> +--- a/gcc/jump.c
> ++++ b/gcc/jump.c
> +@@ -121,15 +121,26 @@ rebuild_jump_labels_chain (rtx chain)
> + static unsigned int
> + cleanup_barriers (void)
> + {
> +-  rtx insn, next, prev;
> +-  for (insn = get_insns (); insn; insn = next)
> ++  rtx insn;
> ++  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
> +     {
> +-      next = NEXT_INSN (insn);
> +       if (BARRIER_P (insn))
> + 	{
> +-	  prev = prev_nonnote_insn (insn);
> ++	  rtx prev = prev_nonnote_insn (insn);
> + 	  if (!prev)
> + 	    continue;
> ++
> ++	  if (CALL_P (prev))
> ++	    {
> ++	      /* Make sure we do not split a call and its corresponding
> ++		 CALL_ARG_LOCATION note.  */
> ++	      rtx next = NEXT_INSN (prev);
> ++
> ++	      if (NOTE_P (next)
> ++		  && NOTE_KIND (next) == NOTE_INSN_CALL_ARG_LOCATION)
> ++		prev = next;
> ++	    }
> ++
> + 	  if (BARRIER_P (prev))
> + 	    delete_insn (insn);
> + 	  else if (prev != PREV_INSN (insn))
> +--
> +1.7.9.5
> +
> diff --git a/meta/recipes-devtools/gcc/gcc-4.9/0059-gcc-PR-rtl-optimization-63348.patch b/meta/recipes-devtools/gcc/gcc-4.9/0059-gcc-PR-rtl-optimization-63348.patch
> new file mode 100644
> index 0000000..6d24aa4
> --- /dev/null
> +++ b/meta/recipes-devtools/gcc/gcc-4.9/0059-gcc-PR-rtl-optimization-63348.patch
> @@ -0,0 +1,59 @@
> +From 6eae3e637fcc22d21b51d44d61e3a9cb4825e776 Mon Sep 17 00:00:00 2001
> +From: Jackie Huang <jackie.huang@windriver.com>
> +Date: Thu, 30 Oct 2014 20:37:14 -0700
> +Subject: [PATCH]PR rtl-optimization/63348
> +
> +PR rtl-optimization/63348
> +* emit-rtl.c (try_split): Do not emit extra barrier.
> +
> +Note: this patch is to fix the side effect introduced by r212171 which was reported at:
> +https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63348
> +
> +git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@215613 138bc75d-0d04-0410-961f-82ee72b054a4
> +
> +Upstream-status: Backport [https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=215613]
> +Signed-off-by: Baoshan Pang <baoshan.pang@windriver.com>
> +Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
> +---
> + gcc/emit-rtl.c |   11 -----------
> + 1 files changed, 0 insertions(+), 11 deletions(-)
> +
> +diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
> +index 4736f8d..ae69dbd 100644
> +--- a/gcc/emit-rtl.c
> ++++ b/gcc/emit-rtl.c
> +@@ -3422,7 +3422,6 @@ try_split (rtx pat, rtx trial, int last)
> + {
> +   rtx before = PREV_INSN (trial);
> +   rtx after = NEXT_INSN (trial);
> +-  int has_barrier = 0;
> +   rtx note, seq, tem;
> +   int probability;
> +   rtx insn_last, insn;
> +@@ -3441,14 +3440,6 @@ try_split (rtx pat, rtx trial, int last)
> +
> +   split_branch_probability = -1;
> +
> +-  /* If we are splitting a JUMP_INSN, it might be followed by a BARRIER.
> +-     We may need to handle this specially.  */
> +-  if (after && BARRIER_P (after))
> +-    {
> +-      has_barrier = 1;
> +-      after = NEXT_INSN (after);
> +-    }
> +-
> +   if (!seq)
> +     return trial;
> +
> +@@ -3594,8 +3585,6 @@ try_split (rtx pat, rtx trial, int last)
> +   tem = emit_insn_after_setloc (seq, trial, INSN_LOCATION (trial));
> +
> +   delete_insn (trial);
> +-  if (has_barrier)
> +-    emit_barrier_after (tem);
> +
> +   /* Recursively call try_split for each new insn created; by the
> +      time control returns here that insn will be fully split, so
> +--
> +1.7.1
> +