Merge pull request #275 from grooverdan/10.2-MDEV-11075-crc32-runtime-detect-getauxval

MDEV-11075: Power - runtime detection of optimized instructions

storage/innobase/ut/ut0crc32.cc

@@ -83,6 +83,12 @@ mysys/my_perf.c, contributed by Facebook under the following license.
 #include "my_config.h"
 #include <string.h>
 
+#if defined(__linux__) && defined(HAVE_CRC32_VPMSUM)
+/* Used to detect at runtime if we have vpmsum instructions (PowerISA 2.07) */
+#include <sys/auxv.h>
+#include <bits/hwcap.h>
+#endif
+
 #include "univ.i"
 #include "ut0crc32.h"
 
@@ -740,8 +746,14 @@ ut_crc32_init()
 	}
 
 #elif defined(HAVE_CRC32_VPMSUM)
-	ut_crc32 = ut_crc32_power8;
-	ut_crc32_implementation = "Using POWER8 crc32 instructions";
+#if defined(__linux__)
+	if (getauxval(AT_HWCAP2) & PPC_FEATURE2_ARCH_2_07) {
+#endif
+		ut_crc32 = ut_crc32_power8;
+		ut_crc32_implementation = "Using POWER8 crc32 instructions";
+#if defined(__linux__)
+	}
+#endif
 #endif
 
 }

storage/xtradb/ut/ut0crc32.cc

@@ -336,7 +336,13 @@ ut_crc32_init()
 	}
 
 #elif defined(HAVE_CRC32_VPMSUM)
-	ut_crc32 = ut_crc32_power8;
-	ut_crc32_implementation = "Using POWER8 crc32 instructions";
+#if defined(__linux__)
+	if (getauxval(AT_HWCAP2) & PPC_FEATURE2_ARCH_2_07) {
+#endif
+		ut_crc32 = ut_crc32_power8;
+		ut_crc32_implementation = "Using POWER8 crc32 instructions";
+#if defined(__linux__)
+	}
+#endif
 #endif
 }