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RE: gcc compiler bug
- To: Dale Williamson <Dale dot Williamson at trw dot com>
- Subject: RE: gcc compiler bug
- From: Alan Modra <alan at linuxcare dot com dot au>
- Date: Fri, 2 Jun 2000 11:05:56 +1000 (EST)
- cc: bug-gcc at gnu dot org, Al Danial <Al dot Danial at trw dot com>
On Thu, 1 Jun 2000, Dale Williamson wrote:
> Are you hinting that "playing with NaNs" is dangerous? Nothing
Actually it's not just NaNs. It's floating point in general.
> Just to move 64 bits from one place to another, implementors of C
> compilers are free to choose not to pass these 64 bits through an
> x87 register that will widen them to 80 bits and meddle with them
> before it spits them out.
But you told gcc
double funcd() { return X.x; }
and it's part of the x86 ABI to return a double from a function in a
floating point register (what a revolutionary concept!)
Thus you need to know something about the underlying hardware if
you want to examine bit patterns. This is definitely not a gcc bug.
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