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author | Pieter Wuille <pieter.wuille@gmail.com> | 2017-07-13 16:43:05 -0700 |
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committer | Pieter Wuille <pieter.wuille@gmail.com> | 2017-07-13 16:43:05 -0700 |
commit | a9e82f6512662054f64ed2bde590b2bb0831fc9d (patch) | |
tree | 06f3ff5605cfab45dbc736b917397deef91004e9 /src | |
parent | 7666250ffb4e8fc5c98556e2c8e121c72d6fe54c (diff) | |
download | bitcoin-a9e82f6512662054f64ed2bde590b2bb0831fc9d.tar.xz |
Use cpuid intrinsics instead of asm code
Diffstat (limited to 'src')
-rw-r--r-- | src/random.cpp | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/src/random.cpp b/src/random.cpp index 67efc7d945..bb463aae82 100644 --- a/src/random.cpp +++ b/src/random.cpp @@ -36,6 +36,10 @@ #include <mutex> +#if defined(__x86_64__) || defined(__amd64__) || defined(__i386__) +#include <cpuid.h> +#endif + #include <openssl/err.h> #include <openssl/rand.h> @@ -72,17 +76,8 @@ static bool rdrand_supported = false; static constexpr uint32_t CPUID_F1_ECX_RDRAND = 0x40000000; static void RDRandInit() { - uint32_t eax, ecx, edx; -#if defined(__i386__) && ( defined(__PIC__) || defined(__PIE__)) - // Avoid clobbering ebx, as that is used for PIC on x86. - uint32_t tmp; - __asm__ ("mov %%ebx, %1; cpuid; mov %1, %%ebx": "=a"(eax), "=g"(tmp), "=c"(ecx), "=d"(edx) : "a"(1)); -#else - uint32_t ebx; - __asm__ ("cpuid": "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(1)); -#endif - //! When calling cpuid function #1, ecx register will have this set if RDRAND is available. - if (ecx & CPUID_F1_ECX_RDRAND) { + uint32_t eax, ebx, ecx, edx; + if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) && (ecx & CPUID_F1_ECX_RDRAND)) { LogPrintf("Using RdRand as entropy source\n"); rdrand_supported = true; } |