Created attachment 48091 [details]
reduced testcase

Compiler output:
$ armv7a-hardfloat-linux-gnueabi-gcc -O -g testcase.c 
during RTL pass: vartrack
testcase.c: In function 'foo':
testcase.c:7:1: internal compiler error: in decompose, at rtl.h:2279
    7 | }
      | ^
0x705186 neg_poly_int_rtx
        /repo/gcc-trunk/gcc/rtl.h:2279
0x10120f9 simplify_binary_operation_1
        /repo/gcc-trunk/gcc/simplify-rtx.c:2677
0x1013d05 simplify_binary_operation(rtx_code, machine_mode, rtx_def*, rtx_def*)
        /repo/gcc-trunk/gcc/simplify-rtx.c:2291
0x1013d78 simplify_gen_binary(rtx_code, machine_mode, rtx_def*, rtx_def*)
        /repo/gcc-trunk/gcc/simplify-rtx.c:189
0x1339eca reverse_op
        /repo/gcc-trunk/gcc/var-tracking.c:5942
0x1339eca add_stores
        /repo/gcc-trunk/gcc/var-tracking.c:6211
0xfcc887 note_pattern_stores(rtx_def const*, void (*)(rtx_def*, rtx_def const*, void*), void*)
        /repo/gcc-trunk/gcc/rtlanal.c:1940
0x1333759 add_with_sets
        /repo/gcc-trunk/gcc/var-tracking.c:6634
0xbc03ed cselib_record_sets
        /repo/gcc-trunk/gcc/cselib.c:2644
0xbc196a cselib_process_insn(rtx_insn*)
        /repo/gcc-trunk/gcc/cselib.c:2806
0x13403d8 vt_initialize
        /repo/gcc-trunk/gcc/var-tracking.c:10221
0x134b347 variable_tracking_main_1
        /repo/gcc-trunk/gcc/var-tracking.c:10450
0x134b347 variable_tracking_main()
        /repo/gcc-trunk/gcc/var-tracking.c:10503
0x134b347 execute
        /repo/gcc-trunk/gcc/var-tracking.c:10540
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

$ armv7a-hardfloat-linux-gnueabi-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-armv7a-hardfloat/bin/armv7a-hardfloat-linux-gnueabi-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r10-7327-20200323085706-g2fa4b1ffd6e-checking-yes-rtl-df-extra-armv7a-hardfloat/bin/../libexec/gcc/armv7a-hardfloat-linux-gnueabi/10.0.1/lto-wrapper
Target: armv7a-hardfloat-linux-gnueabi
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++ --enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra --with-cloog --with-ppl --with-isl --with-float=hard --with-fpu=vfpv4 --with-arch=armv7-a --with-sysroot=/usr/armv7a-hardfloat-linux-gnueabi --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=armv7a-hardfloat-linux-gnueabi --with-ld=/usr/bin/armv7a-hardfloat-linux-gnueabi-ld --with-as=/usr/bin/armv7a-hardfloat-linux-gnueabi-as --disable-libstdcxx-pch --prefix=/repo/gcc-trunk//binary-trunk-r10-7327-20200323085706-g2fa4b1ffd6e-checking-yes-rtl-df-extra-armv7a-hardfloat
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.0.1 20200323 (experimental) (GCC)