x86: Update Intel Atom processor family optimization

Enable Intel Silvermont optimization for Intel Goldmont Plus.  Detect more
Intel Airmont processors.  Optimize Intel Tremont like Intel Silvermont
with rep string instructions.

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index b6d5d9d4b1205191aedfefc44c16724c41efa268..916bbf5242675d25ebbd78afa91495182d36ea03 100644 (file)
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -347,18 +347,23 @@ 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.  */
@@ -369,6 +374,19 @@ 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.  */