commit 76d5b2f002a1243ddba06bd646249553353f4322
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu May 21 13:36:54 2020 -0700
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 c432d646ce6806a6..2a801e1856cfe1b3 100644
--- 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. */