From 6b7c58474df3b416b1acb8b58e73b7edf73b8c43 Mon Sep 17 00:00:00 2001 From: Fabian Vogt Date: Mon, 6 Mar 2023 17:50:42 +0100 Subject: [PATCH] The bit for LZCNT is in CPUID 0x80000001, not 1 The GCC headers put bit_LZCNT into the list for CPUID 1 %ecx values, but that corresponds to VMX. LZCNT is actually advertised in CPUID 0x80000001 %ecx, which is also referred to as "ABM" by AMD and some other places. --- lib/rpmrc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git lib/rpmrc.c lib/rpmrc.c index fc2ed5fe2..66ce947ae 100644 --- lib/rpmrc.c +++ lib/rpmrc.c @@ -747,7 +747,6 @@ static inline void cpuid(uint32_t op, uint32_t op2, uint32_t *eax, uint32_t *ebx /* Features (%eax == 1) */ /* %ecx */ #define bit_SSE3 (1 << 0) -#define bit_LZCNT (1 << 5) #define bit_SSSE3 (1 << 9) #define bit_FMA (1 << 12) #define bit_CMPXCHG16B (1 << 13) @@ -762,6 +761,7 @@ static inline void cpuid(uint32_t op, uint32_t op2, uint32_t *eax, uint32_t *ebx /* Extended Features (%eax == 0x80000001) */ /* %ecx */ #define bit_LAHF_LM (1 << 0) +#define bit_LZCNT (1 << 5) /* Extended Features (%eax == 7) */ /* %ebx */ @@ -787,9 +787,10 @@ static int get_x86_64_level(void) if ((op_1_ecx & op_1_ecx_lv2) == op_1_ecx_lv2 && (op_80000001_ecx & bit_LAHF_LM)) level = 2; - const unsigned int op_1_ecx_lv3 = bit_LZCNT | bit_FMA | bit_MOVBE | bit_OSXSAVE | bit_AVX | bit_F16C; + const unsigned int op_1_ecx_lv3 = bit_FMA | bit_MOVBE | bit_OSXSAVE | bit_AVX | bit_F16C; const unsigned int op_7_ebx_lv3 = bit_BMI | bit_AVX2 | bit_BMI2; - if (level == 2 && (op_1_ecx & op_1_ecx_lv3) == op_1_ecx_lv3 && (op_7_ebx & op_7_ebx_lv3) == op_7_ebx_lv3) + if (level == 2 && (op_1_ecx & op_1_ecx_lv3) == op_1_ecx_lv3 && (op_7_ebx & op_7_ebx_lv3) == op_7_ebx_lv3 + && (op_80000001_ecx & bit_LZCNT)) level = 3; const unsigned int op_7_ebx_lv4 = bit_AVX512F | bit_AVX512DQ | bit_AVX512CD | bit_AVX512BW | bit_AVX512VL; -- 2.39.2