[arm] possible bug in G++ 3.4.x

[Paul Brook]

On Tuesday 01 March 2005 15:29, Petko Manolov wrote:
> On Tue, 1 Mar 2005, Paul Brook wrote:
> > The "old" arm-none-elf and arm-linux targets still use SJLJ exceptions.
> > They will probably never be "fixed" as this would involve an ABI change.
>
> Didn't understand that.  How is all non scratch FP registers save at the
> prologue related to the exceptions?

Because SJLJ exception handling is implemented using 
__builtin_setjmp/__builtin_longjmp. These do not save/restore FP register 
state.
If an exception is thrown the FP state will be that at the throwing location.
Thus the prologue must save all call-saved registers if there is a possibility 
that an exception will be caught.

Paul