[Bug target/64061] New: [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[Bug target/64061] New: [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

            Bug ID: 64061
           Summary: [5 Regression] ICE: in gen_rtx_SUBREG, at
                    emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz

Created attachment 34104
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34104&action=edit
reduced testcase

Compiler output:
$ gcc -O2 -g -fno-dce -fno-tree-dce testcase.c                            
testcase.c: In function 'foo':
testcase.c:18:1: internal compiler error: in gen_rtx_SUBREG, at emit-rtl.c:894
 }
 ^
0x8a1ef0 gen_rtx_SUBREG(machine_mode, rtx_def*, int)
        /mnt/svn/gcc-trunk/gcc/emit-rtl.c:894
0xa9b86c lra_substitute_pseudo(rtx_def**, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1813
0xa9b754 lra_substitute_pseudo(rtx_def**, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1827
0xa9b754 lra_substitute_pseudo(rtx_def**, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1827
0xa9b992 lra_substitute_pseudo_within_insn(rtx_insn*, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1846
0xabbc88 process_bb_lives
        /mnt/svn/gcc-trunk/gcc/lra-lives.c:737
0xabc2ea lra_create_live_ranges_1
        /mnt/svn/gcc-trunk/gcc/lra-lives.c:1255
0xabcbc8 lra_create_live_ranges(bool, bool)
        /mnt/svn/gcc-trunk/gcc/lra-lives.c:1329
0xa9c3a7 lra(_IO_FILE*)
        /mnt/svn/gcc-trunk/gcc/lra.c:2361
0xa4c5d1 do_reload
        /mnt/svn/gcc-trunk/gcc/ira.c:5391
0xa4c5d1 execute
        /mnt/svn/gcc-trunk/gcc/ira.c:5561
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r217996 - ICE
4_9 r216937 - OK

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-11-24
                 CC|                            |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |5.0
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vmakarov at redhat dot com

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
It was caused by r217947.

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I have a fix:
>From 54e1b1c2f4ce5bc6a924dbf30adbd8f03d4bdfe8 Mon Sep 17 00:00:00 2001
From: Andrew Pinski <apinski@cavium.com>
Date: Sat, 22 Nov 2014 09:39:48 -0800
Subject: [PATCH] 2014-11-22  Andrew Pinski  <apinski@cavium.com>

        Bug #13244
        * lra.c (lra_substitute_pseudo): Use gen_lowpart_if_possible
        instead of gen_rtx_SUBREG/gen_lowpart_SUBREG.
---
 gcc/ChangeLog.CAVIUM |    6 ++++++
 gcc/lra.c            |    8 +-------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/gcc/ChangeLog.CAVIUM b/gcc/ChangeLog.CAVIUM
index b7a633d..eb883cf 100644
--- a/gcc/ChangeLog.CAVIUM
+++ b/gcc/ChangeLog.CAVIUM
@@ -1,3 +1,9 @@
+2014-11-22  Andrew Pinski  <apinski@cavium.com>
+
+    Bug #13244
+    * lra.c (lra_substitute_pseudo): Use gen_lowpart_if_possible
+    instead of gen_rtx_SUBREG/gen_lowpart_SUBREG.
+
 2014-11-17  Andrew Pinski  <apinski@cavium.com>

     PR ipa/63981
diff --git a/gcc/lra.c b/gcc/lra.c
index ec122c7..3e07339 100644
--- a/gcc/lra.c
+++ b/gcc/lra.c
@@ -1807,13 +1807,7 @@ lra_substitute_pseudo (rtx *loc, int old_regno, rtx
new_reg)
       machine_mode inner_mode = GET_MODE (new_reg);

       if (mode != inner_mode)
-    {
-      if (GET_MODE_SIZE (mode) >= GET_MODE_SIZE (inner_mode)
-          || ! SCALAR_INT_MODE_P (inner_mode))
-        new_reg = gen_rtx_SUBREG (mode, new_reg, 0);
-      else
-        new_reg = gen_lowpart_SUBREG (mode, new_reg);
-    }
+    new_reg = gen_lowpart_if_possible (mode, new_reg);
       *loc = new_reg;
       return true;
     }
-- 
1.7.4.1

This shows up also on aarch64-linux-gnu and mips64-linux-gnu building libgo's
math.go

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[vmakarov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

--- Comment #4 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
Author: vmakarov
Date: Fri Nov 28 19:33:35 2014
New Revision: 218171

URL: https://gcc.gnu.org/viewcvs?rev=218171&root=gcc&view=rev
Log:
2014-11-28  Vladimir Makarov  <vmakarov@redhat.com>

    PR target/64061
    * lra.c (lra_substitute_pseudo): Ignore constant with int mode for
    subreg.

2014-11-28  Vladimir Makarov  <vmakarov@redhat.com>

    PR target/64061
    * gcc.target/i386/pr64061.c: New.


Added:
    trunk/gcc/testsuite/gcc.target/i386/pr64061.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/lra.c
    trunk/gcc/testsuite/ChangeLog

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Is this fixed now?

[Bug target/64061] [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Assuming fixed.