Commit 4a96df73 authored by Matt Turner's avatar Matt Turner

mesa: Replace a priori knowledge of gcc builtins with configure tests.

Presumbly this will let clang and other compilers use the built-ins as
well.

Notice two changes specifically:
   - in _mesa_next_pow_two_64(), always use __builtin_clzll and add a
     static assertion that this is safe.
   - in macros.h, remove the clang-specific definition since it should
     be able to detect __builtin_unreachable in configure.

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com> [C bits]
Reviewed-by: 's avatarIan Romanick <ian.d.romanick@intel.com>
parent 3e008226
......@@ -130,6 +130,15 @@ fi
dnl Check for compiler builtins
AX_GCC_BUILTIN([__builtin_bswap32])
AX_GCC_BUILTIN([__builtin_bswap64])
AX_GCC_BUILTIN([__builtin_clz])
AX_GCC_BUILTIN([__builtin_clzll])
AX_GCC_BUILTIN([__builtin_ctz])
AX_GCC_BUILTIN([__builtin_expect])
AX_GCC_BUILTIN([__builtin_ffs])
AX_GCC_BUILTIN([__builtin_ffsll])
AX_GCC_BUILTIN([__builtin_popcount])
AX_GCC_BUILTIN([__builtin_popcountll])
AX_GCC_BUILTIN([__builtin_unreachable])
AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" = xyes)
......
......@@ -583,6 +583,24 @@ def generate(env):
env.Append(CCFLAGS = ['-fopenmp'])
env.Append(LIBS = ['gomp'])
if gcc_compat:
ccversion = env['CCVERSION']
cppdefines += [
'HAVE___BUILTIN_EXPECT',
'HAVE___BUILTIN_FFS',
'HAVE___BUILTIN_FFSLL',
]
if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('3.4'):
cppdefines += [
'HAVE___BUILTIN_CTZ',
'HAVE___BUILTIN_POPCOUNT',
'HAVE___BUILTIN_POPCOUNTLL',
'HAVE___BUILTIN_CLZ',
'HAVE___BUILTIN_CLZLL',
]
if distutils.version.LooseVersion(ccversion) >= distutils.version.LooseVersion('4.5'):
cppdefines += ['HAVE___BUILTIN_UNREACHABLE']
# Load tools
env.Tool('lex')
env.Tool('yacc')
......
......@@ -1343,7 +1343,7 @@ brw_blorp_blit_program::single_to_blend()
*/
inline int count_trailing_one_bits(unsigned value)
{
#if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) /* gcc 3.4 or later */
#ifdef HAVE___BUILTIN_CTZ
return __builtin_ctz(~value);
#else
return _mesa_bitcount(value & ~(value + 1));
......
......@@ -217,7 +217,7 @@ _mesa_align_realloc(void *oldBuffer, size_t oldSize, size_t newSize,
/*@{*/
#ifndef __GNUC__
#ifndef HAVE___BUILTIN_FFS
/**
* Find the first bit set in a word.
*/
......@@ -246,8 +246,9 @@ ffs(int i)
}
return bit;
}
#endif
#ifndef HAVE___BUILTIN_FFSLL
/**
* Find position of first bit set in given value.
* XXX Warning: this function can only be used on 64-bit systems!
......@@ -271,11 +272,10 @@ ffsll(long long int val)
return 0;
}
#endif /* __GNUC__ */
#endif
#if !defined(__GNUC__) ||\
((__GNUC__ * 100 + __GNUC_MINOR__) < 304) /* Not gcc 3.4 or later */
#ifndef HAVE___BUILTIN_POPCOUNT
/**
* Return number of bits set in given GLuint.
*/
......@@ -288,7 +288,9 @@ _mesa_bitcount(unsigned int n)
}
return bits;
}
#endif
#ifndef HAVE___BUILTIN_POPCOUNTLL
/**
* Return number of bits set in given 64-bit uint.
*/
......
......@@ -377,8 +377,7 @@ _mesa_is_pow_two(int x)
static inline int32_t
_mesa_next_pow_two_32(uint32_t x)
{
#if defined(__GNUC__) && \
((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) /* gcc 3.4 or later */
#ifdef HAVE___BUILTIN_CLZ
uint32_t y = (x != 1);
return (1 + y) << ((__builtin_clz(x - y) ^ 31) );
#else
......@@ -396,13 +395,10 @@ _mesa_next_pow_two_32(uint32_t x)
static inline int64_t
_mesa_next_pow_two_64(uint64_t x)
{
#if defined(__GNUC__) && \
((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) /* gcc 3.4 or later */
#ifdef HAVE___BUILTIN_CLZLL
uint64_t y = (x != 1);
if (sizeof(x) == sizeof(long))
return (1 + y) << ((__builtin_clzl(x - y) ^ 63));
else
return (1 + y) << ((__builtin_clzll(x - y) ^ 63));
STATIC_ASSERT(sizeof(x) == sizeof(long long));
return (1 + y) << ((__builtin_clzll(x - y) ^ 63));
#else
x--;
x |= x >> 1;
......@@ -423,8 +419,7 @@ _mesa_next_pow_two_64(uint64_t x)
static inline GLuint
_mesa_logbase2(GLuint n)
{
#if defined(__GNUC__) && \
((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) /* gcc 3.4 or later */
#ifdef HAVE___BUILTIN_CLZ
return (31 - __builtin_clz(n | 1));
#else
GLuint pos = 0;
......@@ -476,22 +471,30 @@ _mesa_exec_free( void *addr );
#ifndef FFS_DEFINED
#define FFS_DEFINED 1
#ifdef __GNUC__
#ifdef HAVE___BUILTIN_FFS
#define ffs __builtin_ffs
#define ffsll __builtin_ffsll
#else
extern int ffs(int i);
#endif
#ifdef HAVE___BUILTIN_FFSLL
#define ffsll __builtin_ffsll
#else
extern int ffsll(long long int i);
#endif /*__ GNUC__ */
#endif
#endif /* FFS_DEFINED */
#if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) /* gcc 3.4 or later */
#ifdef HAVE___BUILTIN_POPCOUNT
#define _mesa_bitcount(i) __builtin_popcount(i)
#define _mesa_bitcount_64(i) __builtin_popcountll(i)
#else
extern unsigned int
_mesa_bitcount(unsigned int n);
#endif
#ifdef HAVE___BUILTIN_POPCOUNTLL
#define _mesa_bitcount_64(i) __builtin_popcountll(i)
#else
extern unsigned int
_mesa_bitcount_64(uint64_t n);
#endif
......@@ -504,7 +507,7 @@ _mesa_bitcount_64(uint64_t n);
static inline unsigned int
_mesa_fls(unsigned int n)
{
#if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304)
#ifdef HAVE___BUILTIN_CLZ
return n == 0 ? 0 : 32 - __builtin_clz(n);
#else
unsigned int v = 1;
......
......@@ -33,12 +33,12 @@
/**
* __builtin_expect macros
*/
#if !defined(__GNUC__)
#if !defined(HAVE___BUILTIN_EXPECT)
# define __builtin_expect(x, y) (x)
#endif
#ifndef likely
# ifdef __GNUC__
# ifdef HAVE___BUILTIN_EXPECT
# define likely(x) __builtin_expect(!!(x), 1)
# define unlikely(x) __builtin_expect(!!(x), 0)
# else
......@@ -63,20 +63,12 @@
* Unreachable macro. Useful for suppressing "control reaches end of non-void
* function" warnings.
*/
#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 5
#ifdef HAVE___BUILTIN_UNREACHABLE
#define unreachable(str) \
do { \
assert(!str); \
__builtin_unreachable(); \
} while (0)
#elif (defined(__clang__) && defined(__has_builtin))
# if __has_builtin(__builtin_unreachable)
# define unreachable(str) \
do { \
assert(!str); \
__builtin_unreachable(); \
} while (0)
# endif
#endif
#ifndef unreachable
......
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