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Re: [PATCH][SH] CFI directives patch
On 05/23/2012 04:57 AM, Chung-Lin Tang wrote:
With a stack adjustment in the call delay slot, the unwinder will be
4-bytes off the correct adjustment when crossing that frame; this
probably is an issue of how program counters map to FDEs (< vs<=).
CCing Richard Henderson here, who's probably the one to answer this.
Richard, I remember seeing related discussion in the archives on this
issue, as well as comments in the current GCC dwarf2cfi.c:scan_trace()
code, can you confirm?
FWIW, pushing the unwind data from the delay slot to before the call
is exactly what gcc itself does. Though, really, we try very hard to
*not* place unwind-related insn in delay slots.