From 640df69aa124668ee879c1c93bbb4b3234ae13b2 Mon Sep 17 00:00:00 2001
From: Dennis Luxen <info@project-osrm.org>
Date: Fri, 24 May 2024 22:43:03 +0200
Subject: [PATCH] Remove dead CRC32 processor code (#6900)

---
 include/contractor/crc32_processor.hpp | 128 -------------------------
 src/contractor/contractor.cpp          |   1 -
 2 files changed, 129 deletions(-)
 delete mode 100644 include/contractor/crc32_processor.hpp

diff --git a/include/contractor/crc32_processor.hpp b/include/contractor/crc32_processor.hpp
deleted file mode 100644
index 81b0baa08..000000000
--- a/include/contractor/crc32_processor.hpp
+++ /dev/null
@@ -1,128 +0,0 @@
-#ifndef ITERATOR_BASED_CRC32_H
-#define ITERATOR_BASED_CRC32_H
-
-#if defined(__x86_64__) && !defined(__MINGW64__)
-#include <cpuid.h>
-#endif
-
-#include <boost/crc.hpp> // for boost::crc_32_type
-
-#include <iterator>
-
-namespace osrm::contractor
-{
-
-class IteratorbasedCRC32
-{
-  public:
-    bool UsingHardware() const { return use_hardware_implementation; }
-
-    IteratorbasedCRC32() : crc(0) { use_hardware_implementation = DetectHardwareSupport(); }
-
-    template <class Iterator> unsigned operator()(Iterator iter, const Iterator end)
-    {
-        unsigned crc = 0;
-        while (iter != end)
-        {
-            using value_type = typename std::iterator_traits<Iterator>::value_type;
-            const char *data = reinterpret_cast<const char *>(&(*iter));
-
-            if (use_hardware_implementation)
-            {
-                crc = ComputeInHardware(data, sizeof(value_type));
-            }
-            else
-            {
-                crc = ComputeInSoftware(data, sizeof(value_type));
-            }
-            ++iter;
-        }
-        return crc;
-    }
-
-  private:
-    bool DetectHardwareSupport() const
-    {
-        static const int sse42_bit = 0x00100000;
-        const unsigned ecx = cpuid();
-        const bool sse42_found = (ecx & sse42_bit) != 0;
-        return sse42_found;
-    }
-
-    unsigned ComputeInSoftware(const char *str, unsigned len)
-    {
-        crc_processor.process_bytes(str, len);
-        return crc_processor.checksum();
-    }
-
-    // adapted from http://byteworm.com/2010/10/13/crc32/
-    unsigned ComputeInHardware(const char *str, unsigned len)
-    {
-#if defined(__x86_64__)
-        unsigned q = len / sizeof(unsigned);
-        unsigned r = len % sizeof(unsigned);
-        unsigned *p = (unsigned *)str;
-
-        // crc=0;
-        while (q--)
-        {
-            __asm__ __volatile__(".byte 0xf2, 0xf, 0x38, 0xf1, 0xf1;"
-                                 : "=S"(crc)
-                                 : "0"(crc), "c"(*p));
-            ++p;
-        }
-
-        str = reinterpret_cast<char *>(p);
-        while (r--)
-        {
-            __asm__ __volatile__(".byte 0xf2, 0xf, 0x38, 0xf1, 0xf1;"
-                                 : "=S"(crc)
-                                 : "0"(crc), "c"(*str));
-            ++str;
-        }
-#else
-        (void)str;
-        (void)len;
-#endif
-        return crc;
-    }
-
-    inline unsigned cpuid() const
-    {
-        unsigned eax = 0, ebx = 0, ecx = 0, edx = 0;
-        // on X64 this calls hardware cpuid(.) instr. otherwise a dummy impl.
-        __get_cpuid(1, &eax, &ebx, &ecx, &edx);
-        return ecx;
-    }
-
-#if defined(__MINGW64__) || defined(_MSC_VER) || !defined(__x86_64__)
-    inline void __get_cpuid(int /*param*/,
-                            unsigned * /*eax*/,
-                            unsigned * /*ebx*/,
-                            unsigned *ecx,
-                            unsigned * /*edx*/) const
-    {
-        *ecx = 0;
-    }
-#endif
-
-    boost::crc_optimal<32, 0x1EDC6F41, 0x0, 0x0, true, true> crc_processor;
-    unsigned crc;
-    bool use_hardware_implementation;
-};
-
-struct RangebasedCRC32
-{
-    template <typename Iteratable> unsigned operator()(const Iteratable &iterable)
-    {
-        return crc32(std::begin(iterable), std::end(iterable));
-    }
-
-    bool UsingHardware() const { return crc32.UsingHardware(); }
-
-  private:
-    IteratorbasedCRC32 crc32;
-};
-} // namespace osrm::contractor
-
-#endif /* ITERATOR_BASED_CRC32_H */
diff --git a/src/contractor/contractor.cpp b/src/contractor/contractor.cpp
index 87ab042cb..a0b430aa8 100644
--- a/src/contractor/contractor.cpp
+++ b/src/contractor/contractor.cpp
@@ -1,7 +1,6 @@
 #include "contractor/contractor.hpp"
 #include "contractor/contract_excludable_graph.hpp"
 #include "contractor/contracted_edge_container.hpp"
-#include "contractor/crc32_processor.hpp"
 #include "contractor/files.hpp"
 #include "contractor/graph_contractor.hpp"
 #include "contractor/graph_contractor_adaptors.hpp"