[PATCH] x86: Update Intel Atom processor family optimization

[H.J. Lu]

Enable Intel Silvermont optimization for Intel Goldmont Plus.  Detect more
Intel Airmont processors.  Optimize Intel Tremont like Intel Silvermont
with rep string instructions.
---
 sysdeps/x86/cpu-features.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index bfb415f05a..b1e4c2d1aa 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -348,18 +348,23 @@ init_cpu_features (struct cpu_features *cpu_features)
 	    case 0x57:
 	      /* Knights Landing.  Enable Silvermont optimizations.  */
 
+	    case 0x7a:
+	      /* Unaligned load versions are faster than SSSE3
+		 on Goldmont Plus.  */
+
 	    case 0x5c:
 	    case 0x5f:
 	      /* Unaligned load versions are faster than SSSE3
 		 on Goldmont.  */
 
 	    case 0x4c:
+	    case 0x5a:
+	    case 0x75:
 	      /* Airmont is a die shrink of Silvermont.  */
 
 	    case 0x37:
 	    case 0x4a:
 	    case 0x4d:
-	    case 0x5a:
 	    case 0x5d:
 	      /* Unaligned load versions are faster than SSSE3
 		 on Silvermont.  */
@@ -370,6 +375,19 @@ init_cpu_features (struct cpu_features *cpu_features)
 		    | bit_arch_Slow_SSE4_2);
 	      break;
 
+	    case 0x86:
+	    case 0x96:
+	    case 0x9c:
+	      /* Enable rep string instructions, unaligned load, unaligned
+	         copy, pminub and avoid SSE 4.2 on Tremont.  */
+	      cpu_features->feature[index_arch_Fast_Rep_String]
+		|= (bit_arch_Fast_Rep_String
+		    | bit_arch_Fast_Unaligned_Load
+		    | bit_arch_Fast_Unaligned_Copy
+		    | bit_arch_Prefer_PMINUB_for_stringop
+		    | bit_arch_Slow_SSE4_2);
+	      break;
+
 	    default:
 	      /* Unknown family 0x06 processors.  Assuming this is one
 		 of Core i3/i5/i7 processors if AVX is available.  */
-- 
2.26.2