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GCC alwayszero function attribute

296 bytes added, 20:15, 23 October 2009

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== Possible Bug ==

~~Recognizing~~ Calling gimple_call_flags on a gimple stmt representing an indirect call to a virtual method (with a function attribute) always returns 0. This is even though the correct nonzero value of the call flags can be recognized from other parts of gcc.

In For example: tree-ssa-ccp.cmodified with a debugging statement:

<pre>

/* Compute a default value for variable VAR and store it in the

</pre>

In tree-optimize.cmodified with a debugging statement:

<pre>

/* blah.h */

class Blah {

public: virtual int blah() __attribute__((nothrow));

};

/* blah.cpp */

#include "blah.h"

int Blah::blah() {

return 0;

}

int main()

{

Blah b; Blah* p = &b; int x; x = p->blah(); return 0;

}

</pre>

Compiling sample program with gcc trunk build containing above debugging statements:

<pre>

~~[ehren@australia 2]~~$ ~/gcc/dist/bin/g++ blah.cpp main.cpp -O2

Call flags from tree-optimize.c: 64

Call flags from tree-ssa-ccp: 0

Egmetcalfe

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GCC alwayszero function attribute

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