From: Xie jiamei <xiejiamei@hygon.cn>
Date: Tue, 11 Nov 2025 02:28:54 +0000 (+0800)
Subject: Set Prefer_No_AVX512 flag for hygon platform
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1707b233822a503f787ae1b4abdd07949c3ee691;p=thirdparty%2Fglibc.git

Set Prefer_No_AVX512 flag for hygon platform

Benchmarks indicate evex can be more profitable on Hygon hardware
than AVX512. So add Prefer_No_AVX512 to make it run with evex.

Change-Id: Icc59492f71fde7a783a8bd315714ffd6f7ecaf29
Signed-off-by: Li jing <lijing@hygon.cn>
Signed-off-by: Xie jiamei <xiejiamei@hygon.cn>
---

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 5d4437ffdf..ecf10ce44d 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -1129,6 +1129,13 @@ disable_tsx:
 	  cpu_features->preferred[index_arch_AVX_Fast_Unaligned_Load]
 	    &= ~bit_arch_AVX_Fast_Unaligned_Load;
 	}
+      else if (model == 0x7)
+	{
+	  /* Benchmarks indicate evex can be more profitable on Hygon
+	     hardware than AVX512.  */
+	  cpu_features->preferred[index_arch_Prefer_No_AVX512]
+	    |= bit_arch_Prefer_No_AVX512;
+	}
     }
   else
     {