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Re: [PATCH] x86-64: Implement strcpy family IFUNC selectors in C

From: Florian Weimer <fweimer at gapps dot redhat dot com>
To: "H.J. Lu" <hjl dot tools at gmail dot com>, GNU C Library <libc-alpha at sourceware dot org>
Date: Sun, 11 Jun 2017 20:22:21 +0200
Subject: Re: [PATCH] x86-64: Implement strcpy family IFUNC selectors in C
Authentication-results: sourceware.org; auth=none
References: <20170611135042.GA22931@gmail.com>

On 06/11/2017 03:50 PM, H.J. Lu wrote:

All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 doesn't need to reserve a register to make a PLT call.

Shouldn't this rather say, “because, unlike x86, x86-64 supportsPC-relative addressing to access the GOT entry”? That's probably theroot cause of the performance difference.


Thanks,
Florian

Follow-Ups:
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References:
- [PATCH] x86-64: Implement strcpy family IFUNC selectors in C
  - From: H.J. Lu

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