Re: [Tinycc-devel] Bug: malloc + function returning double + comparison between doubles

[Michael Matz]

Hi,

On Sat, 9 Jun 2012, address@hidden wrote:

>    d = malloc (s);

If this returns a pointer with upper 32 bits set (which depends on malloc 
size, fragmentation and moon phase) ...

>    d[0] = 10.0;
>    i = d[0] > f ();

... those are lost in the caller-save/restore code for the address of d[0] 
generated because of the call to f.  This is because the reload was done 
in VT_INT mode, not VT_PTR as it should have been.

I fixed it on the mob branch with a hopefully more reliable testcase using 
alloca (which on x86-64 will always return a pointer with high 32 bit set 
because the stack will be set up that way).

Thomas: as you were last fiddling with arm, you might want to check if the 
test works on it.  The other alloca testcase is #ifdef'ed on i386 and 
x86_64, but that only makes sense if alloca really isn't supported on arm, 
which I can't believe.  If that really is the case callsave_test() needs 
to be conditional too.


Ciao,
Michael.