http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55531
Bug #: 55531
Summary: peephole2 pattern with multiple insns with
match_parallel insn causes corrupted peephole2_insns
matching function
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: amyl...@gcc.gnu.org
Created attachment 28828
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28828
Preprocessed compatibility-atomic-c++0x.cc sources
with epiphany.md updated to r193918, libstdc++-v3 cannot be built:
[amylaar@rowan gcc]$ gdb --args ./cc1plus -fpreprocessed
compatibility-atomic-c++0x.ii -quiet -dumpbase compatibility-atomic-c++0x.cc
-auxbase-strip compatibility-atomic-c++0x.o -g -O2 -Wall -Wextra
-Wwrite-strings -Wcast-qual -Wabi -std=gnu++11 -version -fno-implicit-templates
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections
-frandom-seed=compatibility-atomic-c++0x.lo -ffixed-r40 -ffixed-r41 -ffixed-r42
-ffixed-r43 -o compatibility-atomic-c++0x.s
GNU gdb (GDB) Fedora (7.4.50.20120120-52.fc17)
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License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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and "show warranty" for details.
This GDB was configured as "i686-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /ssd/fsf/bld-epiphany/gcc/cc1plus...done.
Breakpoint 1 at 0x8a496f0: file ../../gcc/gcc/diagnostic.c, line 1145.
Breakpoint 2 at 0x8a4a7b0: file ../../gcc/gcc/diagnostic.c, line 1086.
Breakpoint 3 at 0x80d5d60
Breakpoint 4 at 0x80d6000
File ../../gcc/gcc/tree.h will be skipped when stepping.
(gdb) run
Starting program: /ssd/fsf/bld-epiphany/gcc/cc1plus -fpreprocessed
compatibility-atomic-c++0x.ii -quiet -dumpbase compatibility-atomic-c++0x.cc
-auxbase-strip compatibility-atomic-c++0x.o -g -O2 -Wall -Wextra
-Wwrite-strings -Wcast-qual -Wabi -std=gnu++11 -version -fno-implicit-templates
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections
-frandom-seed=compatibility-atomic-c++0x.lo -ffixed-r40 -ffixed-r41 -ffixed-r42
-ffixed-r43 -o compatibility-atomic-c++0x.s
GNU C++ (GCC) version 4.8.0 20121129 (experimental) (epiphany-elf)
compiled by GNU C version 4.8.0 20121026 (experimental), GMP version
5.0.2, MPFR version 3.1.0, MPC version 0.9
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU C++ (GCC) version 4.8.0 20121129 (experimental) (epiphany-elf)
compiled by GNU C version 4.8.0 20121026 (experimental), GMP version
5.0.2, MPFR version 3.1.0, MPC version 0.9
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 491116e46d28e8306598e4f5150354ea
Program received signal SIGSEGV, Segmentation fault.
0x08958647 in peephole2_insns (x0=0xb6efdab0, insn=0xb6c187bc,
_pmatch_len=0xbfffe908) at ../../gcc/gcc/config/epiphany/epiphany.md:566
566 (match_operand:SI 2 "arith_operand" "rL")))
(gdb) call debug_rtx(x0)
(parallel [
(asm_operands/v ("") ("") 0 []
[]
[] (null):0)
(clobber (mem:BLK (scratch) [0 A8]))
])
(gdb) call debug_rtx(x1)
(return)
The line allegedly from epiphany.md:566 is actually this line in insn-recog.c:
if (XVECLEN (x1, 0) >= 2
from the code generated for the peephole pattern in lines 1028..1034
of epiphany.md.
Here is a bit more context:
L1407: ATTRIBUTE_UNUSED_LABEL
x1 = XVECEXP (x0, 0, 0);
operands[6] = x1;
goto L1408;
L1408: ATTRIBUTE_UNUSED_LABEL
tem = peep2_next_insn (1);
x1 = PATTERN (tem);
if (XVECLEN (x1, 0) >= 2
&& float_operation (x1, VOIDmode))
{
operands[3] = x1;
goto L1409;
}
goto L1540;
Note that XVECLEN (x1, 0) >= 2 is evaluated without checking first that
x1 is a PARALLEL.
I have attached preprocessed compatibility-atomic-c++0x.cc so that you merely
need cc1plus to reproducei the problem.
I have used the configure options
--target=epiphany-elf --enable-languages=c,c++ --enable-werror-always
and the Makefile target 'all-gcc'
