https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88435
Bug ID: 88435
Summary: Compiling with optimizations causes the compiler to
fail.
Product: gcc
Version: 8.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: mattis at mattisborgen dot se
Target Milestone: ---
pdp11-aout-gcc -save-temps -O2 -v -m10 -Ttext 1000 -msoft-float
-nostartfiles -nodefaultlibs -nostdlib -fno-strict-aliasing -fwrapv
-fno-aggressive-loop-optimizations gccbug.c
Using built-in specs.
COLLECT_GCC=pdp11-aout-gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/pdp11-aout/8.2.0/lto-wrapper
Target: pdp11-aout
Configured with: ./configure --target=pdp11-aout --disable-nls
--without-headers --enable-languages=c
Thread model: single
gcc version 8.2.0 (GCC)
COLLECT_GCC_OPTIONS='-save-temps' '-O2' '-v' '-m10' '-Ttext' '1000'
'-msoft-float' '-nostartfiles' '-nodefaultlibs' '-nostdlib'
'-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations'
/usr/local/libexec/gcc/pdp11-aout/8.2.0/cc1 -E -quiet -v -imultilib
msoft-float gccbug.c -m10 -msoft-float -fno-strict-aliasing -fwrapv
-fno-aggressive-loop-optimizations -O2 -fpch-preprocess -o gccbug.i
ignoring nonexistent directory
"/usr/local/lib/gcc/pdp11-aout/8.2.0/../../../../pdp11-aout/sys-include"
ignoring nonexistent directory
"/usr/local/lib/gcc/pdp11-aout/8.2.0/../../../../pdp11-aout/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/lib/gcc/pdp11-aout/8.2.0/include
/usr/local/lib/gcc/pdp11-aout/8.2.0/include-fixed
End of search list.
COLLECT_GCC_OPTIONS='-save-temps' '-O2' '-v' '-m10' '-Ttext' '1000'
'-msoft-float' '-nostartfiles' '-nodefaultlibs' '-nostdlib'
'-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations'
/usr/local/libexec/gcc/pdp11-aout/8.2.0/cc1 -fpreprocessed gccbug.i -quiet
-dumpbase gccbug.c -m10 -msoft-float -auxbase gccbug -O2 -version
-fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations -o gccbug.s
GNU C17 (GCC) version 8.2.0 (pdp11-aout)
compiled by GNU C version 4.2.1 Compatible Apple LLVM 5.0
(clang-500.2.76), GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl
version none
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C17 (GCC) version 8.2.0 (pdp11-aout)
compiled by GNU C version 4.2.1 Compatible Apple LLVM 5.0
(clang-500.2.76), GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl
version none
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: bc392ef67ca9ec448731a9f0a726ee14
gccbug.c: In function 'pollConsole':
gccbug.c:11:1: error: unrecognizable insn:
}
^
(insn 13 12 14 2 (set (reg:SI 35)
(ashift:SI (reg:SI 34)
(const_int -9 [0xfffffffffffffff7]))) "gccbug.c":5 -1
(nil))
during RTL pass: vregs
gccbug.c:11:1: internal compiler error: in extract_insn, at recog.c:2304
libbacktrace could not find executable to open
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.
$ cat gccbug.c
int pollConsole () {
volatile unsigned int * rxcsr = (unsigned int *) 0177560;
unsigned int tmp = 512 & *rxcsr;
if (tmp == 512) {
return 1;
}
else {
return 0;
}
}
The compile fail if the two literals 512 is equal and greater than 16. It also
has to have one single bit set. I.e. 32, 64, 128...
33,34 woks fine.
$ cat gccbug.i
# 1 "gccbug.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "gccbug.c"
int pollConsole () {
volatile unsigned int * rxcsr = (unsigned int *) 0177560;
unsigned int tmp = 512 & *rxcsr;
if (tmp == 512) {
return 1;
}
else {
return 0;
}
}
