[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


From: Kip Warner
Subject: AX_CHECK_X86_FEATURES behaviour
Date: Mon, 27 May 2019 11:28:12 -0700
User-agent: Evolution 3.32.1-2

Hey list,

I am using AX_CHECK_X86_FEATURES in my to check for
various CPU features. 

I noticed when building for s390x architecture the macro bailed because
the s390x' gcc's __builtin_cpu_init function is needed to perform the
probe but doesn't exist. I read up on that function and it appears
that's only available on i*86 and amd64 hosts. 

What I had expected the macro to do was to check for certain features,
set various flags accordingly, and that's it. If the
__builtin_cpu_init() function doesn't exist, I would have expected it
to set all flags to false and that would be the end of it.

I realize it may be tempting to suggest that one should only use this
macro when they are certain the host (or build as well?) are of i*86 or
amd64 architectures, but that partially defeats the whole point of the
macro and the intention behind portable configure scripts.

Should this be considered a design flaw or bug in
AX_CHECK_X86_FEATURES? Or should I check prior to calling it whether it
can be called?

Kip Warner | Senior Software Engineer
OpenPGP signed/encrypted mail preferred

Attachment: signature.asc
Description: This is a digitally signed message part

reply via email to

[Prev in Thread] Current Thread [Next in Thread]