On 24 May 2013 18:17, Richard Henderson <r...@twiddle.net> wrote: > On 05/24/2013 10:08 AM, Peter Maydell wrote: >> Where's the waste? The procedure calling standard mandates that we >> set FP up, so it's not like we can use it as a general purpose >> register anywhere. > > Well, the calling standard is another document that's not available > yet
Nope, it's been available for ages, along with the ELF and DWARF specs and the C++ ABI: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ihi0055b/index.html > so obviously I don't know the rationale for that decision. But > it does seem like a register performing no useful function... It does what a frame pointer usually does, ie permits the debugger (and other tools) to unwind the stack. thanks -- PMM
