------- Comment #16 from zadeck at naturalbridge dot com 2007-07-02 00:19 ------- Subject: Re: [4.3 Regression] function with asm() does not setup stack frame
Ian Lance Taylor wrote: >> Adding the stack pointer for asms is certainly the easiest thing to do. >> > > I don't know if that is enough. Maybe it is, maybe it isn't. You > can't delete the subtraction of the stack pointer if there is any use > of any local variable on the frame in any way. If an interrupt > occurs, and the stack pointer has not been decremented to be below the > local variables, then the local variables will be corrupted by the > interrupt handler. > > >> If you think that we want to view mem refs off the frame pointer as if >> they also touch the stack pointer, we can do that, but i would ask the >> question as to "why just in dce?" >> > > I meant it should be done when doing dataflow scanning, not in DCE. I > agree there is nothing special about DCE here. > ian, a set of specific questions: 1) Do i do this for both the frame_pointer and hard_frame_pointer? 2) There is currently code in the scanning for adding the stack pointer for call insns. This code marks that ref so that it is not considered when building log links for combine. a) Should I mark the stack pointer ref added for asm's this way? b) Should I mark the stack pointer refs put in for the mems in this way? Kenny -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32475
