https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84123
Bug ID: 84123
Summary: internal compiler error: in gen_rtx_SUBREG, at
emit-rtl.c:908, alpha linux.
Product: gcc
Version: 8.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: mcree at orcon dot net.nz
Target Milestone: ---
Target: alpha
Created attachment 43286
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43286&action=edit
Preprocessed source
The attached preprocessed source (modified from the libcgns project) leads to
an ICE at optimisation level -O2 but compiles fine at -O1 or -O0. I have
trimmed the source substantially from its original but trimming it further
loses the ICE.
ICE seen with Debian alpha-linux-gnu-gcc version 7.3.0-1 and also with gcc
recently compiled from the trunk (8.0.1 20180129).
alpha-linux-gnu-gcc -O2 -c test-preprocessed.c
/home/mjc/debian/libcgns/libcgns-3.3.0/src/adf/test.c: In function
‘ADFI_ID_2_file_block_offset.part.0’:
/home/mjc/debian/libcgns/libcgns-3.3.0/src/adf/test.c:619:1: internal compiler
error: in gen_rtx_SUBREG, at emit-rtl.c:908
Recent gcc prints out more information:
./toolchain/gcc-install/bin/gcc -mcpu=ev4 -O2 -c test-preprocessed.c
during RTL pass: combine
/home/mjc/debian/libcgns/libcgns-3.3.0/src/adf/test.c: In function
‘ADFI_ID_2_file_block_offset.part.0’:
/home/mjc/debian/libcgns/libcgns-3.3.0/src/adf/test.c:619:1: internal compiler
error: in gen_rtx_SUBREG, at emit-rtl.c:1010
0x12041b91f gen_rtx_SUBREG(machine_mode, rtx_def*, poly_int<1u, unsigned long>)
../../gcc.git/gcc/emit-rtl.c:1010
0x120f7057f change_zero_ext
../../gcc.git/gcc/combine.c:11496
0x120f7087f recog_for_combine
../../gcc.git/gcc/combine.c:11596
0x120f86d43 try_combine
../../gcc.git/gcc/combine.c:3595
0x120f8abcf combine_instructions
../../gcc.git/gcc/combine.c:1320
0x120f8abcf rest_of_handle_combine
../../gcc.git/gcc/combine.c:14856
0x120f8abcf execute
../../gcc.git/gcc/combine.c:14901
