[Bug c/15103] New: postincrement precedence lower than assignment

["musicman529 at yahoo dot com" <gcc-bugzilla at gcc dot gnu dot org>]

In the following program:
==========================================
#include <stdio.h>
 
int main(int argc, char *argv[]) {
  int x = 20, y = 35;
  x = x++ + y++;
  y = ++x + ++y;
  printf("x=%d y=%d\n", x, y);
  return 0;
}
==========================================

In the first assignment line "x = x++ + y++;", the code emitted by the i386
compiler processes the post-increment operators after the assignment, so that
the addition result gets incremented in "x".

1. Shouldn't "x++" be semantically equivalent to "(x += 1, x - 1)"? The first
assignment produced assembly that behaved more like:
x = x + y;
x++;
y++;
I tried to use parentheses around the increment expressions to force the
precedence, but they were ignored.

2. Don't the increment and decrement operators have a much higher precedence
than assignment?

I'll admit, any coder working for me who wrote code like the above, would be
fired on the spot. This is a very small corner case. However, it may point to a
larger issue that needs to be resolved, so I'm filing it "just in case".

-- 
           Summary: postincrement precedence lower than assignment
           Product: gcc
           Version: 3.3.3
            Status: UNCONFIRMED
          Severity: minor
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: musicman529 at yahoo dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i486-slackware-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15103