[Bug target/84799] ICE on valid code at -O1: in lra_split_hard_reg_for, at lra-assigns.c:1802

[tschwinge at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84799

Thomas Schwinge <tschwinge at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-03-10
                 CC|                            |tschwinge at gcc dot gnu.org,
                   |                            |vmakarov at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Thomas Schwinge <tschwinge at gcc dot gnu.org> ---
I'm seeing something like this also during libgomp build of the -m32 multilib
of x86_64-pc-linux-gnu:

    /bin/sh ./libtool --tag=CC   --mode=compile [...]/build-gcc/./gcc/xgcc
-B[...]/build-gcc/./gcc/ -B/x86_64-pc-linux-gnu/bin/
-B/x86_64-pc-linux-gnu/lib/ -isystem /x86_64-pc-linux-gnu/include -isystem
/x86_64-pc-linux-gnu/sys-include    -DHAVE_CONFIG_H -I.
-I[...]/source-gcc/libgomp  -I[...]/source-gcc/libgomp/config/linux/x86
-I[...]/source-gcc/libgomp/config/linux -I[...]/source-gcc/libgomp/config/posix
-I[...]/source-gcc/libgomp -I[...]/source-gcc/libgomp/../include  -Wall -Werror
-ftls-model=initial-exec -march=i486 -mtune=generic -Wc,-pthread  -g -O2  -m32
-MT affinity.lo -MD -MP -MF .deps/affinity.Tpo -c -o affinity.lo
[...]/source-gcc/libgomp/config/linux/affinity.c
    libtool: compile:  [...]/build-gcc/./gcc/xgcc -B[...]/build-gcc/./gcc/
-B/x86_64-pc-linux-gnu/bin/ -B/x86_64-pc-linux-gnu/lib/ -isystem
/x86_64-pc-linux-gnu/include -isystem /x86_64-pc-linux-gnu/sys-include
-DHAVE_CONFIG_H -I. -I[...]/source-gcc/libgomp
-I[...]/source-gcc/libgomp/config/linux/x86
-I[...]/source-gcc/libgomp/config/linux -I[...]/source-gcc/libgomp/config/posix
-I[...]/source-gcc/libgomp -I[...]/source-gcc/libgomp/../include -Wall -Werror
-ftls-model=initial-exec -march=i486 -pthread -mtune=generic -g -O2 -m32 -MT
affinity.lo -MD -MP -MF .deps/affinity.Tpo -c
[...]/source-gcc/libgomp/config/linux/affinity.c  -fPIC -DPIC -o
.libs/affinity.o
    [...]/source-gcc/libgomp/config/linux/affinity.c: In function
'gomp_affinity_copy_place':
    [...]/source-gcc/libgomp/config/linux/affinity.c:174:1: error: unable to
find a register to spill
     }
     ^
    [...]/source-gcc/libgomp/config/linux/affinity.c:174:1: error: this is the
insn:
    (insn 189 222 220 14 (parallel [
                (set (reg:SI 154 [140])
                    (ashift:SI (reg:SI 154 [140])
                        (reg:QI 156)))
                (clobber (reg:CC 17 flags))
            ]) "[...]/source-gcc/libgomp/config/linux/affinity.c":171 540
{*ashlsi3_1}
         (expr_list:REG_DEAD (reg:QI 156)
            (expr_list:REG_UNUSED (reg:CC 17 flags)
                (nil))))
    during RTL pass: reload
    [...]/source-gcc/libgomp/config/linux/affinity.c:174:1: internal compiler
error: in lra_split_hard_reg_for, at lra-assigns.c:1802
    0x103d65f _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
            [...]/source-gcc/gcc/rtl-error.c:108
    0xe1e911 lra_split_hard_reg_for()
            [...]/source-gcc/gcc/lra-assigns.c:1802
    0xe170b1 lra(_IO_FILE*)
            [...]/source-gcc/gcc/lra.c:2506
    0xda636b do_reload
            [...]/source-gcc/gcc/ira.c:5465
    0xda6860 execute
            [...]/source-gcc/gcc/ira.c:5649

Bisected to r258390 (PR83712).