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From: Jun Koi <junkoi2004@gmail.com>
Date: Wed, 28 Apr 2010 13:51:49 +0900
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Subject: [Qemu-devel] Question on implementatio of GETPC()
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To: qemu-devel@nongnu.org

Hi,

In x86, GETPC() is implemented as below:

# define GETPC() ((void *)((unsigned long)__builtin_return_address(0) - 1))

As I understand, it gets the returned address on the stack, then
subtract 1 to get back to the above address.

Imagine we have code like this (pseudo asm code):

....
CALL <relative address>
<next-insn>
....

When we call GETPC, we get the address of <next-insn>, and subtract 1.
But the problem is that the CALL insn is more than 1 byte, so how can
GETPC() gives us the address of the CALL insn above?

I guess I must misunderstood something here ....

Many thanks,
Jun