Re: Efficient x86 and x86_64 NOP microbenchmarks

From: Jeremy Fitzhardinge
Date: Wed Aug 13 2008 - 16:07:52 EST


Steven Rostedt wrote:
No, I can easily make a patch that does not use frame pointers but still uses -pg. We just can not print the parent function in the trace. This can easily be added to a config, as well as easily implemented.

Why? You can always get the calling function, because its return address is on the stack (assuming mcount is called before the function puts its own frame on the stack). But without a frame pointer, you can't necessarily get the caller's caller.

But I think Andi's point is that gcc forces frame pointers on when you enable mcount, so there's no choice in the matter.

J
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