optimization/8300: [3.2/3.3/3.4 regression] [sparc] ICE in gen_reg_rtx, at emit-rtl.c:662

[Andreas Schwab]

Robert Schiele <rschiele@uni-mannheim.de> writes:

|> On Mon, Mar 17, 2003 at 09:29:37AM -0500, Daniel Jacobowitz wrote:
|> > If you have a copy of the standard, it's 6.5.6#8.  Once a pointer is
|> > adjusted to point outside of the original object it must not be
|> > dereferenced.  Accessing memory in this way produces undefined
|> > behavior.
|> 
|> Ok thanks, found it there.
|> 
|> How about this:
|> 
|> void a() {
|>     double b;
|>     int c[2];
|>     *((int*)&b) && (c[1] = 0);
|> }
|> 
|> Exactly same problem.  And this time there is no pointer outside well
|> defined data area.  You agree that this sample is legal code?

Ignoring the missing initialisation of b this is undefined under the
aliasing rules.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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