[Bug target/59896] New: Thumb-1 LRA unable to generate reloads for jump_insn

[Bug target/59896] New: Thumb-1 LRA unable to generate reloads for jump_insn

[terry.guo at arm dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59896

            Bug ID: 59896
           Summary: Thumb-1 LRA unable to generate reloads for jump_insn
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: terry.guo at arm dot com

Created attachment 31903
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31903&action=edit
A preprocessed test case

Use trunk gcc to compile attached case with command "arm-none-eabi-gcc -mthumb
-O2 -S dtoa.i", we will get below error:

/home/build/work/GCC-4-9-build/src/newlib/newlib/libc/stdlib/dtoa.c: In
function '_dtoa_r':
/home/build/work/GCC-4-9-build/src/newlib/newlib/libc/stdlib/dtoa.c:862:1:
error: unable to generate reloads for:
(jump_insn 424 2763 425 32 (parallel [
            (set (pc)
                (if_then_else (ge (plus:SI (reg:SI 491 [ D.6302 ])
                            (const_int -1 [0xffffffffffffffff]))
                        (const_int 0 [0]))
                    (label_ref:SI 427)
                    (pc)))
            (set (reg/v:SI 178 [ s2 ])
                (plus:SI (reg:SI 491 [ D.6302 ])
                    (const_int -1 [0xffffffffffffffff])))
            (clobber (reg:SI 833))
        ])
/home/build/work/GCC-4-9-build/src/newlib/newlib/libc/stdlib/dtoa.c:369 225
{*addsi3_cbranch}
     (expr_list:REG_UNUSED (reg:SI 833)
        (expr_list:REG_DEAD (reg:SI 491 [ D.6302 ])
            (int_list:REG_BR_PROB 7300 (nil))))
 -> 427)
/home/build/work/GCC-4-9-build/src/newlib/newlib/libc/stdlib/dtoa.c:862:1:
internal compiler error: in curr_insn_transform, at lra-constraints.c:3220
0xaa7a9b _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
    /myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/rtl-error.c:109
0x9a9f71 curr_insn_transform
   
/myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/lra-constraints.c:3220
0x9acb2a lra_constraints(bool)
   
/myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/lra-constraints.c:4115
0x999647 lra(_IO_FILE*)
    /myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/lra.c:2339
0x947791 do_reload
    /myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/ira.c:5457
0x947ada rest_of_handle_reload
    /myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/ira.c:5598
0x947b24 execute
    /myssd/terguo01/toolchain-build/thumb1-uxtb/src/gcc/gcc/ira.c:5627
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.

The gcc version is:
gcc version 4.9.0 20140120 (experimental) 

If we disable LRA, there is no such issue.

[Bug rtl-optimization/59896] [4.9 regression] Bootstrap: Thumb-1 LRA unable to generate reloads for jump_insn

[rearnsha at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59896

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code, ra
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-01-21
          Component|target                      |rtl-optimization
            Summary|Thumb-1 LRA unable to       |[4.9 regression] Bootstrap:
                   |generate reloads for        |Thumb-1 LRA unable to
                   |jump_insn                   |generate reloads for
                   |                            |jump_insn
     Ever confirmed|0                           |1

--- Comment #1 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
This prevents building newlib during a bootstrap.

Seems to have started with:

2014-01-16  Vladimir Makarov  <vmakarov@redhat.com>

        PR middle-end/59609
        * lra-constraints.c (process_alt_operands): Add printing debug
        info.  Check absence of input/output reloads for matched operands
        too.

[Bug rtl-optimization/59896] [4.9 regression] Bootstrap: Thumb-1 LRA unable to generate reloads for jump_insn

[vmakarov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59896

--- Comment #2 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
Author: vmakarov
Date: Tue Jan 21 21:26:33 2014
New Revision: 206908

URL: http://gcc.gnu.org/viewcvs?rev=206908&root=gcc&view=rev
Log:
2014-01-21  Vladimir Makarov  <vmakarov@redhat.com>

    PR rtl-optimization/59896
    * lra-constraints.c (process_alt_operands): Check unused note for
    matched operands of insn with no output reloads.

2014-01-21  Vladimir Makarov  <vmakarov@redhat.com>

    PR rtl-optimization/59896
    * gcc.target/arm/pr59896.c: New.


Added:
    trunk/gcc/testsuite/gcc.target/arm/pr59896.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/lra-constraints.c
    trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/59896] [4.9 regression] Bootstrap: Thumb-1 LRA unable to generate reloads for jump_insn

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59896

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |law at redhat dot com
         Resolution|---                         |FIXED

--- Comment #3 from Jeffrey A. Law <law at redhat dot com> ---
Fixed by Vlad's commit on the trunk.