From 87b8bde55dc1700f212b2249b9c150714df67369 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 18 Jun 2024 17:34:48 +0200 Subject: [PATCH] Revert "host/i386: assume presence of SSE2" This reverts commit b18236897ca15c3db1506d8edb9a191dfe51429c. The x86-64 instruction set can now be tuned down to x86-64 v1 or i386 Pentium Pro. Signed-off-by: Paolo Bonzini --- host/include/i386/host/bufferiszero.c.inc | 5 +++-- host/include/i386/host/cpuinfo.h | 1 + util/cpuinfo-i386.c | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/host/include/i386/host/bufferiszero.c.inc b/host/include/i386/host/bufferiszero.c.inc index 3b9605d806..74ae98580f 100644 --- a/host/include/i386/host/bufferiszero.c.inc +++ b/host/include/i386/host/bufferiszero.c.inc @@ -110,13 +110,14 @@ static biz_accel_fn const accel_table[] = { static unsigned best_accel(void) { -#ifdef CONFIG_AVX2_OPT unsigned info = cpuinfo_init(); + +#ifdef CONFIG_AVX2_OPT if (info & CPUINFO_AVX2) { return 2; } #endif - return 1; + return info & CPUINFO_SSE2 ? 1 : 0; } #else diff --git a/host/include/i386/host/cpuinfo.h b/host/include/i386/host/cpuinfo.h index 72f6fad61e..81771733ea 100644 --- a/host/include/i386/host/cpuinfo.h +++ b/host/include/i386/host/cpuinfo.h @@ -14,6 +14,7 @@ #define CPUINFO_POPCNT (1u << 4) #define CPUINFO_BMI1 (1u << 5) #define CPUINFO_BMI2 (1u << 6) +#define CPUINFO_SSE2 (1u << 7) #define CPUINFO_AVX1 (1u << 9) #define CPUINFO_AVX2 (1u << 10) #define CPUINFO_AVX512F (1u << 11) diff --git a/util/cpuinfo-i386.c b/util/cpuinfo-i386.c index ca74ef04f5..90f92a42dc 100644 --- a/util/cpuinfo-i386.c +++ b/util/cpuinfo-i386.c @@ -34,6 +34,7 @@ unsigned __attribute__((constructor)) cpuinfo_init(void) if (max >= 1) { __cpuid(1, a, b, c, d); + info |= (d & bit_SSE2 ? CPUINFO_SSE2 : 0); info |= (c & bit_MOVBE ? CPUINFO_MOVBE : 0); info |= (c & bit_POPCNT ? CPUINFO_POPCNT : 0); info |= (c & bit_PCLMUL ? CPUINFO_PCLMUL : 0);