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Re: Can shrink-wrapping ever move prologue past an ASM statement?
- From: Jeff Law <law at redhat dot com>
- To: GCC Mailing List <gcc at gcc dot gnu dot org>, Vojtech Pavlik <vojtech at suse dot cz>
- Date: Tue, 07 Jul 2015 14:25:34 -0600
- Subject: Re: Can shrink-wrapping ever move prologue past an ASM statement?
- Authentication-results: sourceware.org; auth=none
- References: <20150707175349 dot GA2325 at virgil dot suse dot cz>
On 07/07/2015 11:53 AM, Martin Jambor wrote:
I've been asked to look into the item one of
http://permalink.gmane.org/gmane.linux.kernel/1990397 and found out
that at least shrink-wrapping happily moves prologue past an asm
statement which can be bad if the asm statement contains a call
Am I right concluding that this is a bug? Looking into the manual and
at requires_stack_frame_p() in shrink-wrap.c, I do not see any obvious
way of marking the asm statement as requiring the stack frame (but I
will not mind being proven wrong). Do we want to create one, such as
only disallowing moving prologue past volatile asm statements? Any
Shouldn't this be driven by dataflow?