https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78602
Bug ID: 78602
Summary: PowerPC vec-extract-v2df.c can fail if -mcpu=power9
-O0
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: meissner at gcc dot gnu.org
Target Milestone: ---
In doing testing of a future patch, I forgot to apply any optimization when I
was building the vec-extract-v*.c tests for -mcpu=power9, and the compiler
fails with an insn not found error:
-genoa-> ./xgcc -B./ -save-temps -c -mcpu=power9 vec-extract-v2df.c
In file included from vec-extract-v2df.c:9:0:
vec-extract.h: In function 'get_auto_n':
vec-extract.h:36:1: error: unrecognizable insn:
}
^
(insn 8 7 9 2 (parallel [
(set (reg:DF 158)
(unspec:DF [
(reg:V2DF 157)
(mem/c:DI (plus:DI (reg/f:DI 150 virtual-stack-vars)
(const_int 16 [0x10])) [4 n+0 S8 A64])
] UNSPEC_VSX_EXTRACT))
(clobber (scratch:DI))
(clobber (scratch:V2DI))
]) "vec-extract.h":35 -1
(nil))
vec-extract.h:36:1: internal compiler error: in extract_insn, at recog.c:2311
0x10888313 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
/home/meissner/fsf-src/trunk-242932/gcc/rtl-error.c:108
0x10888377 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
/home/meissner/fsf-src/trunk-242932/gcc/rtl-error.c:116
0x1084bc4b extract_insn(rtx_insn*)
/home/meissner/fsf-src/trunk-242932/gcc/recog.c:2311
0x105703a7 instantiate_virtual_regs_in_insn
/home/meissner/fsf-src/trunk-242932/gcc/function.c:1589
0x105703a7 instantiate_virtual_regs
/home/meissner/fsf-src/trunk-242932/gcc/function.c:1956
0x105703a7 execute
/home/meissner/fsf-src/trunk-242932/gcc/function.c:2005
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 cause of the error is the rs6000_expand_vector_extract function was
expecting the element number to be either a constant or a register. Normal
optimization does a force_reg before doing the expansion in the hopes of
letting GCSE find common instructions. However if no optimization is used,
this is not done.
