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Commit025c024

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Speed up CRC calculation using slicing-by-8 algorithm.
This speeds up WAL generation and replay. The new algorithm issignificantly faster with large inputs, like full-page images or wheninserting wide rows. It is slower with tiny inputs, i.e. less than 10 bytesor so, but the speedup with longer inputs more than make up for that. Evensmall WAL records at least have 24 byte header in the front.The output is identical to the current byte-at-a-time computation, so thisdoes not affect compatibility. The new algorithm is only used for theCRC-32C variant, not the legacy version used in tsquery or the"traditional" CRC-32 used in hstore and ltree. Those are not as performancecritical, and are usually only applied over small inputs, so it seemsbetter to not carry around the extra lookup tables to speed up those rarecases.Abhijit Menon-Sen
1 parentcc761b1 commit025c024

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7 files changed

+1246
-85
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7 files changed

+1246
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‎config/c-compiler.m4

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@@ -193,6 +193,23 @@ fi])# PGAC_C_TYPES_COMPATIBLE
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# PGAC_C_BUILTIN_BSWAP32
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# -------------------------
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# Check if the C compiler understands __builtin_bswap32(),
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# and define HAVE__BUILTIN_BSWAP32 if so.
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AC_DEFUN([PGAC_C_BUILTIN_BSWAP32],
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[AC_CACHE_CHECK(for__builtin_bswap32,pgac_cv__builtin_bswap32,
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[AC_TRY_COMPILE([static unsigned long int x = __builtin_bswap32(0xaabbccdd);],
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[],
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[pgac_cv__builtin_bswap32=yes],
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[pgac_cv__builtin_bswap32=no])])
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if test x"$pgac_cv__builtin_bswap32" = xyes ; then
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AC_DEFINE(HAVE__BUILTIN_BSWAP32,1,
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[Define to 1 if your compiler understands __builtin_bswap32.])
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fi])# PGAC_C_BUILTIN_BSWAP32
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# PGAC_C_BUILTIN_CONSTANT_P
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# -------------------------
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# Check if the C compiler understands __builtin_constant_p(),

‎configure

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Original file line numberDiff line numberDiff line change
@@ -10332,6 +10332,36 @@ if test x"$pgac_cv__types_compatible" = xyes ; then
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$as_echo"#define HAVE__BUILTIN_TYPES_COMPATIBLE_P 1">>confdefs.h
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fi
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{$as_echo"$as_me:${as_lineno-$LINENO}: checking for __builtin_bswap32">&5
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$as_echo_n"checking for __builtin_bswap32...">&6; }
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if${pgac_cv__builtin_bswap32+:}false;then:
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$as_echo_n"(cached)">&6
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else
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cat confdefs.h -<<_ACEOF >conftest.$ac_ext
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/* end confdefs.h. */
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static unsigned long int x = __builtin_bswap32(0xaabbccdd);
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int
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main ()
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{
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;
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return 0;
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}
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_ACEOF
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if ac_fn_c_try_compile"$LINENO";then:
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pgac_cv__builtin_bswap32=yes
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else
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pgac_cv__builtin_bswap32=no
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fi
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rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
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fi
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{$as_echo"$as_me:${as_lineno-$LINENO}: result:$pgac_cv__builtin_bswap32">&5
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$as_echo"$pgac_cv__builtin_bswap32">&6; }
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iftest x"$pgac_cv__builtin_bswap32" = xyes;then
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$as_echo"#define HAVE__BUILTIN_BSWAP32 1">>confdefs.h
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fi
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{$as_echo"$as_me:${as_lineno-$LINENO}: checking for __builtin_constant_p">&5
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$as_echo_n"checking for __builtin_constant_p...">&6; }

‎configure.in

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Original file line numberDiff line numberDiff line change
@@ -1185,6 +1185,7 @@ PGAC_C_SIGNED
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PGAC_C_FUNCNAME_SUPPORT
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PGAC_C_STATIC_ASSERT
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PGAC_C_TYPES_COMPATIBLE
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PGAC_C_BUILTIN_BSWAP32
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PGAC_C_BUILTIN_CONSTANT_P
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PGAC_C_BUILTIN_UNREACHABLE
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PGAC_C_VA_ARGS

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