https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118878
Bug ID: 118878
Summary: [ice][avr] internal compiler error: in avr_out_plus_1,
at config/avr/avr.cc:8801
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: gjl at gcc dot gnu.org
Target Milestone: ---
Created attachment 60499
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60499&action=edit
C test case
The attached test case ICEs with
$ avr-gcc read-dw.c -S -mmcu=atmega8 -Os
during RTL pass: shorten
dump file: read-dw.c.361r.shorten
read-dw.c: In function 'test':
read-dw.c:59:1: internal compiler error: in avr_out_plus_1, at
config/avr/avr.cc:8801
Reason is the following insn:
(insn 84 25 122 (parallel [
(set (reg:SI 20 r20 [orig:63 pf_14 ] [63])
(plus:SI (reg:SI 20 r20 [orig:61 _3 ] [61])
(reg:SI 22 r22 [orig:56 __tmp ] [56])))
(clobber (scratch:QI))
(clobber (reg:CC 36 cc))
]) "read-dw.c":56:17 219 {*addsi3}
for which avr.cc::avr_out_plus_1() decides that such an overlap makes no sense:
if (reg_overlap_mentioned_p (xop[0], xop[2]))
{
gcc_assert (REGNO (xop[0]) == REGNO (xop[2]));
Target: avr
Configured with: ../../source/gcc-master/configure --target=avr --disable-nls
--with-dwarf2 --with-gnu-as --with-gnu-ld --with-long-double=64
--disable-libcc1 --disable-shared --enable-languages=c,c++
Thread model: single
Supported LTO compression algorithms: zlib
gcc version 15.0.1 20250212 (experimental) (GCC)
