From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 3 Jun 2019 15:21:05 +0000 (+0200)
Subject: x86: further speed-up to hweight{32,64}()
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2133
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=291c68f10e8ec6dc46737f27617949fd2f04e6ef;p=xen.git

x86: further speed-up to hweight{32,64}()

According to Linux commit 0136611c62 ("optimize hweight64 for x86_64")
this is a further improvement over the variant using only bitwise
operations. It's also a slight further code size reduction.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 4b8b07b549..f502d765ba 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -12,6 +12,7 @@ config X86
 	select HAS_CPUFREQ
 	select HAS_EHCI
 	select HAS_EX_TABLE
+	select HAS_FAST_MULTIPLY
 	select HAS_GDBSX
 	select HAS_IOPORTS
 	select HAS_KEXEC