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From: "gjl at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/64052] compilation error "local frame unavailable" appears for some optimization levels
Date: Sat, 29 Nov 2014 20:27:00 -0000 [thread overview]
Message-ID: <bug-64052-4-DaMA2nyQwB@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-64052-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64052
Georg-Johann Lay <gjl at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |gjl at gcc dot gnu.org
--- Comment #3 from Georg-Johann Lay <gjl at gcc dot gnu.org> ---
I think this PR is invalid:
Your code rets up avariable which needs a place to be stored, which is the
function frame for non-optimized code. As the function is naked, no frame is
available to store the value.
If the compiler would not check this and proceed compilation, the resulting
code would be non-functional. This is similar for C. Consider
extern void fun (int*);
__attribute__((naked))
void test (void)
{
int x;
fun (&x);
}
There's no place to store x here, and this even applies to optimized code.
Apart from this, the documentation for "naked" attribute reads:
>> [...] It allows the compiler to construct the requisite function
>> declaration, while allowing the body of the function to be
>> assembly code.
>> [...] Only Basic asm statements can safely be included in naked
>> functions. While using Extended asm or a mixture of Basic asm
>> and C code may appear to work, they cannot be depended upon to
>> work reliably and are not supported.
next prev parent reply other threads:[~2014-11-29 20:27 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-24 14:40 [Bug c++/64052] New: " eugene at hutorny dot in.ua
2014-11-24 16:14 ` [Bug target/64052] " rguenth at gcc dot gnu.org
2014-11-25 18:24 ` eugene at hutorny dot in.ua
2014-11-29 20:27 ` gjl at gcc dot gnu.org [this message]
2014-11-29 20:41 ` eugene at hutorny dot in.ua
2015-02-16 18:09 ` gjl at gcc dot gnu.org
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