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Diffstat (limited to 'src/liblzma/check/crc_clmul.c')
-rw-r--r--src/liblzma/check/crc_clmul.c45
1 files changed, 0 insertions, 45 deletions
diff --git a/src/liblzma/check/crc_clmul.c b/src/liblzma/check/crc_clmul.c
index 7110fd7e..640415e7 100644
--- a/src/liblzma/check/crc_clmul.c
+++ b/src/liblzma/check/crc_clmul.c
@@ -372,48 +372,3 @@ lzma_crc64_clmul(const uint8_t *buf, size_t size, uint64_t crc)
&& defined(_M_IX86)
# pragma optimize("", on)
#endif
-
-
-////////////////////////
-// Detect CPU support //
-////////////////////////
-
-extern bool
-lzma_is_clmul_supported(void)
-{
- int success = 1;
- uint32_t r[4]; // eax, ebx, ecx, edx
-
-#if defined(_MSC_VER)
- // This needs <intrin.h> with MSVC. ICC has it as a built-in
- // on all platforms.
- __cpuid(r, 1);
-#elif defined(HAVE_CPUID_H)
- // Compared to just using __asm__ to run CPUID, this also checks
- // that CPUID is supported and saves and restores ebx as that is
- // needed with GCC < 5 with position-independent code (PIC).
- success = __get_cpuid(1, &r[0], &r[1], &r[2], &r[3]);
-#else
- // Just a fallback that shouldn't be needed.
- __asm__("cpuid\n\t"
- : "=a"(r[0]), "=b"(r[1]), "=c"(r[2]), "=d"(r[3])
- : "a"(1), "c"(0));
-#endif
-
- // Returns true if these are supported:
- // CLMUL (bit 1 in ecx)
- // SSSE3 (bit 9 in ecx)
- // SSE4.1 (bit 19 in ecx)
- const uint32_t ecx_mask = (1 << 1) | (1 << 9) | (1 << 19);
- return success && (r[2] & ecx_mask) == ecx_mask;
-
- // Alternative methods that weren't used:
- // - ICC's _may_i_use_cpu_feature: the other methods should work too.
- // - GCC >= 6 / Clang / ICX __builtin_cpu_supports("pclmul")
- //
- // CPUID decding is needed with MSVC anyway and older GCC. This keeps
- // the feature checks in the build system simpler too. The nice thing
- // about __builtin_cpu_supports would be that it generates very short
- // code as is it only reads a variable set at startup but a few bytes
- // doesn't matter here.
-}