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-rw-r--r--src/liblzma/check/crc_common.h64
1 files changed, 0 insertions, 64 deletions
diff --git a/src/liblzma/check/crc_common.h b/src/liblzma/check/crc_common.h
index c949f793..552219fe 100644
--- a/src/liblzma/check/crc_common.h
+++ b/src/liblzma/check/crc_common.h
@@ -108,70 +108,6 @@
# define CRC_USE_GENERIC_FOR_SMALL_INPUTS 1
# endif
*/
-
-# if defined(_MSC_VER)
-# include <intrin.h>
-# elif defined(HAVE_CPUID_H)
-# include <cpuid.h>
-# endif
-
-// is_clmul_supported() must be inlined in this header file because the
-// ifunc resolver function may not support calling a function in another
-// translation unit. Depending on compiler-toolchain and flags, a call to
-// a function defined in another translation unit could result in a
-// reference to the PLT, which is unsafe to do in an ifunc resolver. The
-// ifunc resolver runs very early when loading a shared library, so the PLT
-// entries may not be setup at that time. Inlining this function duplicates
-// the function body in crc32_resolve() and crc64_resolve(), but this is
-// acceptable because the function results in very few instructions.
-static inline bool
-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.
-}
-
-#endif
-
-/// CRC32 implemented with the x86 CLMUL instruction.
-extern uint32_t lzma_crc32_clmul(const uint8_t *buf, size_t size,
- uint32_t crc);
-
-/// CRC64 implemented with the x86 CLMUL instruction.
-extern uint64_t lzma_crc64_clmul(const uint8_t *buf, size_t size,
- uint64_t crc);
-
#endif