c++/9167: Optimization breaks operator overloading (regression)

[Peter Schmid <schmid at snake dot iap dot physik dot tu-darmstadt dot de>]

>Number:         9167
>Category:       c++
>Synopsis:       Optimization breaks operator overloading (regression)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          ice-on-legal-code
>Submitter-Id:   net
>Arrival-Date:   Fri Jan 03 17:36:01 PST 2003
>Closed-Date:
>Last-Modified:
>Originator:     Peter Schmid
>Release:        3.4 20021231 (experimental)
>Organization:
LBNL
>Environment:
System: Linux kiste 2.4.18 #10 Thu Dec 26 00:47:26 CET 2002 i686 unknown
Architecture: i686

	
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: 
>Description:
Optimization, -O or more, breaks the following simple source code. The
code compiles normally, when the constructor and the destructor
definitions are removed. This a regression with respect to previous
gcc snapshots. 
>How-To-Repeat:
source code tc.C
class A {
private:
	const int n;
public:
	A(const int n_) : n(n_) { }
	A(const A& x) : n(x.n) { }
	~A() { }
	A operator^(A) const {
		A result(n);
		return result;
	}
	A& operator=(const A) {
		return *this;
	}

};


void f(void)
{
  A a_1(16);
  a_1 = a_1 ^ a_1;
}


Compiling tc.C
with optimization
g++ -O -v -W -Wall tc.C
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/specs
Configured with: 
Thread model: posix
gcc version 3.4 20021231 (experimental)
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/cc1plus -quiet -v -D__GNUC__=3 -D__GNUC_MINOR__=4 -D__GNUC_PATCHLEVEL__=0 -D_GNU_SOURCE tc.C -D__GNUG__=3 -quiet -dumpbase tc.C -auxbase tc -O -W -Wall -version -o /tmp/ccVohn8F.s
GNU C++ version 3.4 20021231 (experimental) (i686-pc-linux-gnu)
	compiled by GNU C version 3.4 20021231 (experimental).
ignoring nonexistent directory "NONE/include"
ignoring nonexistent directory "/usr/local/i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/c++/3.4
 /usr/local/include/c++/3.4/i686-pc-linux-gnu
 /usr/local/include/c++/3.4/backward
 /usr/local/include
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/include
 /usr/include
End of search list.
tc.C: In function `void f()':
tc.C:8: internal compiler error: in simplify_gen_subreg, at simplify-rtx.c:2629
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.


without optimization
g++ -v -W -Wall tc.C
Reading specs from /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/specs
Configured with: 
Thread model: posix
gcc version 3.4 20021231 (experimental)
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/cc1plus -quiet -v -D__GNUC__=3 -D__GNUC_MINOR__=4 -D__GNUC_PATCHLEVEL__=0 -D_GNU_SOURCE tc.C -D__GNUG__=3 -quiet -dumpbase tc.C -auxbase tc -W -Wall -version -o /tmp/ccCN4wKN.s
GNU C++ version 3.4 20021231 (experimental) (i686-pc-linux-gnu)
	compiled by GNU C version 3.4 20021231 (experimental).
ignoring nonexistent directory "NONE/include"
ignoring nonexistent directory "/usr/local/i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/c++/3.4
 /usr/local/include/c++/3.4/i686-pc-linux-gnu
 /usr/local/include/c++/3.4/backward
 /usr/local/include
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/include
 /usr/include
End of search list.
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/../../../../i686-pc-linux-gnu/bin/as -V -Qy -o /tmp/ccg9UB1y.o /tmp/ccCN4wKN.s
GNU assembler version 2.13.90.0.4 (i686-pc-linux-gnu) using BFD version 2.13.90.0.4 20020814
 /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/collect2 --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 /usr/lib/crt1.o /usr/lib/crti.o /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/crtbegin.o -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4 -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/../../../../i686-pc-linux-gnu/lib -L/usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/../../.. /tmp/ccg9UB1y.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/local/lib/gcc-lib/i686-pc-linux-gnu/3.4/crtend.o /usr/lib/crtn.o
/usr/lib/crt1.o: In function `_start':
/usr/lib/crt1.o(.text+0x18): undefined reference to `main'
collect2: ld returned 1 exit status

Compilation exited abnormally with code 1 at Sat Jan  4 02:33:24

>Fix:
	
>Release-Note:
>Audit-Trail:
>Unformatted: