Re: optimization/8994: [3.2/3.3 regression] ICE with -O -march=pentium4

[Wolfgang Bangerth <bangerth@ticam.utexas.edu>]

The following reply was made to PR optimization/8994; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
To: "Joseph S. Myers" <jsm28@cam.ac.uk>
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: optimization/8994: [3.2/3.3 regression] ICE with -O -march=pentium4
Date: Wed, 18 Dec 2002 15:08:46 -0600 (CST)

 On Wed, 18 Dec 2002, Joseph S. Myers wrote:
 
 > On 18 Dec 2002, Wolfgang Bangerth wrote:
 > 
 > >  I may be blind, but if I remember right then a compound statement is a 
 > >  ({...}) thing, of which there is exactly one, and it does not have a label 
 > >  at its end. However, this warning is given by all gcc versions I checked.
 > 
 > No, that's a statement expression, which contains a compound statement.  
 > A compound statement is simply { ...  }.
 
 Oh, sorry, then I was confused. Still, the testcase is
 ----------------------------
 typedef union {
   double value;
   int lsw;
 } astr;
 
 void js_dtoa(double d)
 {
   while(1)
     if (( { astr sh_u; sh_u.value = d; sh_u.lsw; }) & 1)
       goto ret;
 ret:
 }
 ---------------------------
 
 Why is it warning about this:
 
 tmp/regression/test/PR8994.c: In function `js_dtoa':
 tmp/regression/test/PR8994.c:12: warning: deprecated use of label at end 
                                  of compound statement
 
 The compound statement is then actually the function body, and this seems 
 like a pretty common technique. Also, saying deprecated means that it is 
 either deprecated by the standard, or it is illegal but accepted by gcc as 
 an extension. It is the latter, right, since a label must be followed by 
 another statement, and be it only ";".
 
 W.
 
 -------------------------------------------------------------------------
 Wolfgang Bangerth              email:           bangerth@ticam.utexas.edu
                                www: http://www.ticam.utexas.edu/~bangerth