Hi,
This patch fixes PR64935, which is triggered when ready list at the start of a basic block is greater than --param=max-sched-ready-insns. Sorting the ready list when it has more than max-sched-ready-insns elements is special in that we want to sort normal insns even if there are debug insns in the list. This is due to code for max-sched-ready-insns ignoring debug insns on purpose.
The problem in the bug can be fixed with a smallish patch (seehttps://gcc.gnu.org/bugzilla/attachment.cgi?id=34674), but it makes code look ugly and non-intuitive. The second version of the patch (the one attached here) is a bit bigger, but it gives functions definitive and clear purpose, and makes code easier to understand.
While reviewing the patch I suggest using context diff mode (in emacs C-c C-d). I couldn't convince git to generate context diff.
Bootstrapped/tested on x86_64-linux-gnu and cross-tested on arm-linux-gnueabihf. Markus also tested this patch on powerpc64-linux-gnu.
OK for trunk?
Thank you,
--
Maxim Kuvyrkov
www.linaro.org
0001-Fix-PR64935.patch
From 339d0af94509796d08101724ea54e1d3787f89f2 Mon Sep 17 00:00:00 2001
From: Maxim Kuvyrkov<maxim.kuvyrkov@linaro.org>
Date: Wed, 18 Feb 2015 15:27:49 +0000
Subject: [PATCH] Fix PR64935
* haifa-sched.c (enum rfs_decision, rfs_str): Remove RFS_DEBUG.
(rank_for_schedule_debug): Update.
(ready_sort): Make static. Move sorting logic to ...
(ready_sort_debug, ready_sort_real): New static functions.
(schedule_block): Sort both debug insns and real insns in preparation
for ready list trimming. Improve debug output.
* sched-int.h (ready_sort): Remove global declaration.
* gcc.dg/pr64935-1.c, gcc.dg/pr64935-2.c: New tests.