Re: [Bug rtl-optimization/21402] wrong-code with inlining and type-punned pointer

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

"schlie at comcast dot net" <gcc-bugzilla@gcc.gnu.org> writes:

| (In reply to comment #4)
| > Subject: Re:  wrong-code with inlining and type-punned pointer
| > Because this is what the standard says is allowed.  The standard also
| > says the comparisons and assignment between pointers without a case is
| > invalid code and should be diagnostic.  Again this is what the standard
| > says for these things and GCC follows the C standard.
| 
| Here's an interesting portion of the standard, which seems to direcly imply
| that signed and unsigned lvalue references are presumed to validly alias; so
| so this should place both in the same alias set, and potentially eliminate the
| default warning when comparing pointers which differ only in signness, as

Sorry, I don't see that implication.  However, GCC already has a
switch for tuning off such comparison.

-- Gaby