From 9ef36faa614528b66e0a6ba58a4c40b246658b83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= <marko.makela@mariadb.com>
Date: Fri, 28 Aug 2020 14:44:36 +0300
Subject: [PATCH] MDEV-23618 InnoDB lacks IA-32 CRC-32C acceleration on GCC 4

When MDEV-22669 introduced CRC-32C acceleration to IA-32,
it worked around a compiler bug by disabling the acceleration
on GCC 4 for IA-32 altogether, even though the compiler bug
only affects -fPIC builds that are targeting IA-32.

Let us extend the solution fe5dbfe723427a3606c41409626dc853f997e679
and define HAVE_CPUID_INSTRUCTION that allows us to implement
a necessary and sufficient work-around of the compiler bug.
---
 config.h.cmake                  |  1 +
 mysys/CMakeLists.txt            |  5 ++++-
 storage/innobase/ut/ut0crc32.cc | 14 ++------------
 3 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/config.h.cmake b/config.h.cmake
index 0de5c2be3e0..3e41e0ac3af 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -103,6 +103,7 @@
 #cmakedefine HAVE_LIBWRAP 1
 #cmakedefine HAVE_SYSTEMD 1
 
+#cmakedefine HAVE_CPUID_INSTRUCTION 1
 #cmakedefine HAVE_CLMUL_INSTRUCTION 1
 #cmakedefine HAVE_CRC32_VPMSUM 1
 
diff --git a/mysys/CMakeLists.txt b/mysys/CMakeLists.txt
index f72608aa1a9..54f78922f2b 100644
--- a/mysys/CMakeLists.txt
+++ b/mysys/CMakeLists.txt
@@ -58,7 +58,9 @@ IF (WIN32)
     my_win_popen.cc)
 ENDIF()
 
-IF(NOT MSVC AND CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64|i[36]86")
+IF(MSVC)
+  SET(HAVE_CPUID_INSTRUCTION 1 CACHE BOOL "")
+ELSEIF(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64|i[36]86")
   #Check for CPUID and PCLMUL. GCC before version 5 would refuse to emit the
   #CPUID instruction for -m32 -fPIC because it would clobber the EBX register.
   CHECK_C_SOURCE_COMPILES("
@@ -70,6 +72,7 @@ IF(NOT MSVC AND CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|amd64|i[36]86")
   }" HAVE_CLMUL_INSTRUCTION)
 
   IF(HAVE_CLMUL_INSTRUCTION)
+    SET(HAVE_CPUID_INSTRUCTION 1 CACHE BOOL "")
     SET(MYSYS_SOURCES ${MYSYS_SOURCES} crc32/crc32_x86.c)
   ENDIF()
 ELSEIF(CMAKE_SYSTEM_PROCESSOR MATCHES "aarch64|AARCH64")
diff --git a/storage/innobase/ut/ut0crc32.cc b/storage/innobase/ut/ut0crc32.cc
index 1ddac168d95..80a0d165069 100644
--- a/storage/innobase/ut/ut0crc32.cc
+++ b/storage/innobase/ut/ut0crc32.cc
@@ -102,17 +102,7 @@ const char*	ut_crc32_implementation = "Using POWER8 crc32 instructions";
 extern "C" {
 uint32_t crc32c_aarch64(uint32_t crc, const unsigned char *buffer, uint64_t len);
 };
-# elif defined(_MSC_VER)
-#  define TRY_SSE4_2
-# elif defined (__GNUC__)
-#  ifdef __x86_64__
-#   define TRY_SSE4_2
-#  elif defined(__i386__) && (__GNUC__ > 4 || defined __clang__)
-#   define TRY_SSE4_2
-#  endif
-# endif
-
-# ifdef TRY_SSE4_2
+# elif defined HAVE_CPUID_INSTRUCTION
 /** return whether SSE4.2 instructions are available */
 static inline bool has_sse4_2()
 {
@@ -349,7 +339,7 @@ void ut_crc32_init()
     ut_crc32_implementation= crc32c_implementation;
     return;
   }
-# elif defined(TRY_SSE4_2)
+# elif defined HAVE_CPUID_INSTRUCTION
   if (has_sse4_2())
   {
     ut_crc32_low= ut_crc32_hw;