[Mesa-dev] [PATCH 1/8] configure.ac: Use AX_GCC_BUILTIN to check availability of __builtin_bswap32

Tom Stellard thomas.stellard at amd.com
Thu Feb 20 10:21:40 PST 2014


---
 configure.ac                        |   6 ++
 m4/ax_gcc_builtin.m4                | 168 ++++++++++++++++++++++++++++++++++++
 src/gallium/auxiliary/util/u_math.h |   3 +-
 3 files changed, 176 insertions(+), 1 deletion(-)
 create mode 100644 m4/ax_gcc_builtin.m4

diff --git a/configure.ac b/configure.ac
index 8390d27..75d345a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -119,6 +119,12 @@ if test "x$GCC" = xyes -a "x$acv_mesa_CLANG" = xno; then
         GEN_ASM_OFFSETS=yes
     fi
 fi
+
+dnl Check for compiler builtins
+AX_GCC_BUILTIN([__builtin_bswap32])
+
+AC_SUBST(HAVE___BUILTIN_BSWAP32)
+
 AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" = xyes)
 
 dnl Make sure the pkg-config macros are defined
diff --git a/m4/ax_gcc_builtin.m4 b/m4/ax_gcc_builtin.m4
new file mode 100644
index 0000000..b28a91b
--- /dev/null
+++ b/m4/ax_gcc_builtin.m4
@@ -0,0 +1,168 @@
+# ===========================================================================
+#      http://www.gnu.org/software/autoconf-archive/ax_gcc_builtin.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_GCC_BUILTIN(BUILTIN)
+#
+# DESCRIPTION
+#
+#   This macro checks if the compiler supports one of GCC's built-in
+#   functions; many other compilers also provide those same built-ins.
+#
+#   The BUILTIN parameter is the name of the built-in function.
+#
+#   If BUILTIN is supported define HAVE_<BUILTIN>. Keep in mind that since
+#   builtins usually start with two underscores they will be copied over
+#   into the HAVE_<BUILTIN> definition (e.g. HAVE___BUILTIN_EXPECT for
+#   __builtin_expect()).
+#
+#   The macro caches its result in the ax_cv_have_<BUILTIN> variable (e.g.
+#   ax_cv_have___builtin_expect).
+#
+#   The macro currently supports the following built-in functions:
+#
+#    __builtin_assume_aligned
+#    __builtin_bswap32
+#    __builtin_bswap64
+#    __builtin_choose_expr
+#    __builtin___clear_cache
+#    __builtin_clrsb
+#    __builtin_clrsbl
+#    __builtin_clrsbll
+#    __builtin_clz
+#    __builtin_clzl
+#    __builtin_clzll
+#    __builtin_complex
+#    __builtin_constant_p
+#    __builtin_ctz
+#    __builtin_ctzl
+#    __builtin_ctzll
+#    __builtin_expect
+#    __builtin_ffs
+#    __builtin_ffsl
+#    __builtin_ffsll
+#    __builtin_fpclassify
+#    __builtin_huge_val
+#    __builtin_huge_valf
+#    __builtin_huge_vall
+#    __builtin_inf
+#    __builtin_infd128
+#    __builtin_infd32
+#    __builtin_infd64
+#    __builtin_inff
+#    __builtin_infl
+#    __builtin_isinf_sign
+#    __builtin_nan
+#    __builtin_nand128
+#    __builtin_nand32
+#    __builtin_nand64
+#    __builtin_nanf
+#    __builtin_nanl
+#    __builtin_nans
+#    __builtin_nansf
+#    __builtin_nansl
+#    __builtin_object_size
+#    __builtin_parity
+#    __builtin_parityl
+#    __builtin_parityll
+#    __builtin_popcount
+#    __builtin_popcountl
+#    __builtin_popcountll
+#    __builtin_powi
+#    __builtin_powif
+#    __builtin_powil
+#    __builtin_prefetch
+#    __builtin_trap
+#    __builtin_types_compatible_p
+#    __builtin_unreachable
+#
+#   Unsuppored built-ins will be tested with an empty parameter set and the
+#   result of the check might be wrong or meaningless so use with care.
+#
+# LICENSE
+#
+#   Copyright (c) 2013 Gabriele Svelto <gabriele.svelto at gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 2
+
+AC_DEFUN([AX_GCC_BUILTIN], [
+    AS_VAR_PUSHDEF([ac_var], [ax_cv_have_$1])
+
+    AC_CACHE_CHECK([for $1], [ac_var], [
+        AC_LINK_IFELSE([AC_LANG_PROGRAM([], [
+            m4_case([$1],
+                [__builtin_assume_aligned], [$1("", 0)],
+                [__builtin_bswap32], [$1(0)],
+                [__builtin_bswap64], [$1(0)],
+                [__builtin_choose_expr], [$1(0, 0, 0)],
+                [__builtin___clear_cache], [$1("", "")],
+                [__builtin_clrsb], [$1(0)],
+                [__builtin_clrsbl], [$1(0)],
+                [__builtin_clrsbll], [$1(0)],
+                [__builtin_clz], [$1(0)],
+                [__builtin_clzl], [$1(0)],
+                [__builtin_clzll], [$1(0)],
+                [__builtin_complex], [$1(0.0, 0.0)],
+                [__builtin_constant_p], [$1(0)],
+                [__builtin_ctz], [$1(0)],
+                [__builtin_ctzl], [$1(0)],
+                [__builtin_ctzll], [$1(0)],
+                [__builtin_expect], [$1(0, 0)],
+                [__builtin_ffs], [$1(0)],
+                [__builtin_ffsl], [$1(0)],
+                [__builtin_ffsll], [$1(0)],
+                [__builtin_fpclassify], [$1(0, 1, 2, 3, 4, 0.0)],
+                [__builtin_huge_val], [$1()],
+                [__builtin_huge_valf], [$1()],
+                [__builtin_huge_vall], [$1()],
+                [__builtin_inf], [$1()],
+                [__builtin_infd128], [$1()],
+                [__builtin_infd32], [$1()],
+                [__builtin_infd64], [$1()],
+                [__builtin_inff], [$1()],
+                [__builtin_infl], [$1()],
+                [__builtin_isinf_sign], [$1(0.0)],
+                [__builtin_nan], [$1("")],
+                [__builtin_nand128], [$1("")],
+                [__builtin_nand32], [$1("")],
+                [__builtin_nand64], [$1("")],
+                [__builtin_nanf], [$1("")],
+                [__builtin_nanl], [$1("")],
+                [__builtin_nans], [$1("")],
+                [__builtin_nansf], [$1("")],
+                [__builtin_nansl], [$1("")],
+                [__builtin_object_size], [$1("", 0)],
+                [__builtin_parity], [$1(0)],
+                [__builtin_parityl], [$1(0)],
+                [__builtin_parityll], [$1(0)],
+                [__builtin_popcount], [$1(0)],
+                [__builtin_popcountl], [$1(0)],
+                [__builtin_popcountll], [$1(0)],
+                [__builtin_powi], [$1(0, 0)],
+                [__builtin_powif], [$1(0, 0)],
+                [__builtin_powil], [$1(0, 0)],
+                [__builtin_prefetch], [$1("")],
+                [__builtin_trap], [$1()],
+                [__builtin_types_compatible_p], [$1(int, int)],
+                [__builtin_unreachable], [$1()],
+                [m4_warn([syntax], [Unsupported built-in $1, the test may fail])
+                 $1()]
+            )
+            ])],
+            [AS_VAR_SET([ac_var], [yes])],
+            [AS_VAR_SET([ac_var], [no])])
+    ])
+
+    AS_IF([test yes = AS_VAR_GET([ac_var])],
+        [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$1), 1,
+            [Define to 1 if the system has the `$1' built-in function])], [])
+
+    AS_VAR_POPDEF([ac_var])
+])
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index b5e0663..b0f0e3d 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -731,7 +731,8 @@ util_bitcount(unsigned n)
 static INLINE uint32_t
 util_bswap32(uint32_t n)
 {
-#if defined(PIPE_CC_GCC) && (PIPE_CC_GCC_VERSION >= 403)
+/* We need the gcc version checks for non-autoconf build system */
+#if defined(HAVE___BUILTIN_BSWAP32) || (defined(PIPE_CC_GCC) && (PIPE_CC_GCC_VERSION >= 403))
    return __builtin_bswap32(n);
 #else
    return (n >> 24) |
-- 
1.8.1.4




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