the FPU is using 53-bit precision. Here are macros that force this. See
Python/pystrtod.c for an example of their use. */
-#ifdef USING_X87_FPU
+#ifdef HAVE_GCC_ASM_FOR_X87
#define _Py_SET_53BIT_PRECISION_HEADER \
unsigned short old_387controlword, new_387controlword
#define _Py_SET_53BIT_PRECISION_START \
value: str(1e11 + 0.5). (This minor issue has existed in 2.x for a
long time.)
-- On x86, SSE2 instructions for floating-point are automatically
- detected and, where possible, enabled on platforms using the gcc
- compiler. As a consequence, some arithmetic operations may have
- different (more accurate!) results on some platforms, and
- cross-platform consistency of Python arithmetic should be improved.
- This applies particularly to Linux/x86.
-
- Issue #1580: On most platforms, use a 'short' float repr: for a
finite float x, repr(x) now outputs a string based on the shortest
sequence of decimal digits that rounds to x. Previous behaviour was
#define MAX(x, y) ((x) < (y) ? (y) : (x))
#define MIN(x, y) ((x) < (y) ? (x) : (y))
+/* ascii character tests (as opposed to locale tests) */
+#define ISSPACE(c) ((c) == ' ' || (c) == '\f' || (c) == '\n' || \
+ (c) == '\r' || (c) == '\t' || (c) == '\v')
+#define ISDIGIT(c) ((c) >= '0' && (c) <= '9')
+
#ifdef HAVE_IEEEFP_H
#include <ieeefp.h>
#endif
}
last = s + len;
- while (*s && isspace(Py_CHARMASK(*s)))
+ while (*s && ISSPACE(Py_CHARMASK(*s)))
s++;
if (*s == '\0') {
PyErr_SetString(PyExc_ValueError, "empty string for float()");
}
/* Since end != s, the platform made *some* kind of sense out
of the input. Trust it. */
- while (*end && isspace(Py_CHARMASK(*end)))
+ while (*end && ISSPACE(Py_CHARMASK(*end)))
end++;
if (*end != '\0') {
PyOS_snprintf(buffer, sizeof(buffer),
********************/
/* leading whitespace and optional sign */
- while (isspace(Py_CHARMASK(*s)))
+ while (ISSPACE(Py_CHARMASK(*s)))
s++;
if (*s == '-') {
s++;
s_store = s;
if (*s == '0') {
s++;
+ if (*s == 'x' || *s == 'X')
if (tolower(*s) == (int)'x')
s++;
else
exp = 0;
/* optional trailing whitespace leading to the end of the string */
- while (isspace(Py_CHARMASK(*s)))
+ while (ISSPACE(Py_CHARMASK(*s)))
s++;
if (s != s_end)
goto parse_error;
}
#endif
-#ifdef USING_X87_FPU
-# ifdef HAVE_GCC_ASM_FOR_X87
+#ifdef HAVE_GCC_ASM_FOR_X87
/* inline assembly for getting and setting the 387 FPU control word on
gcc/x86 */
__asm__ __volatile__ ("fldcw %0" : : "m" (cw));
}
-# else
-# error "Unable to get and set x87 control word"
-# endif
#endif
#! /bin/sh
-# From configure.in Revision: 71663 .
+# From configure.in Revision: 71704 .
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.61 for python 3.1.
#
fi
-# David Gay's code in Python/dtoa.c requires that the FPU uses 53-bit
+# The short float repr introduced in Python 3.1 requires the
+# correctly-rounded string <-> double conversion functions in
+# Python/dtoa.c, which in turn require that the FPU uses 53-bit
# rounding; this is a particular problem on x86, where the x87 FPU has
# a default rounding precision of 64 bits. For gcc/x86, we try to fix
-# this by:
-#
-# (1) using the SSE2 instruction set when available (it usually is
-# on modern machines)
-# (2) using inline assembler to get and set the x87 FPU control word
-# otherwise.
-#
-# On AMD64 (aka x86-64), gcc automatically enables use of SSE2
-# instructions, so we don't bother trying to detect.
+# this by using inline assembler to get and set the x87 FPU control
+# word.
if test "$GCC" = yes && test -n "`$CC -dM -E - </dev/null | grep i386`"
then
- # determine whether we're already using the SSE2 instruction set for math
- # (e.g., this is true by default on OS X/x86)
- { echo "$as_me:$LINENO: checking whether SSE2 instructions are already enabled for math" >&5
-echo $ECHO_N "checking whether SSE2 instructions are already enabled for math... $ECHO_C" >&6; }
- if test -n "`$CC -dM -E - </dev/null | grep __SSE2_MATH__`"
- then
- ac_sse2_enabled=yes
- else
- ac_sse2_enabled=no
- fi
- { echo "$as_me:$LINENO: result: $ac_sse2_enabled" >&5
-echo "${ECHO_T}$ac_sse2_enabled" >&6; }
-
- # if we're not using SSE2 already, we need to either enable it
- # (when available), or use inline assembler to get and set the
- # 387 control word.
- if test $ac_sse2_enabled = no
- then
- # Check cpuid for SSE2 availability. Bits 25 and 26 of edx tell
- # us about SSE and SSE2 respectively.
- { echo "$as_me:$LINENO: checking whether SSE2 instructions are available on this CPU" >&5
-echo $ECHO_N "checking whether SSE2 instructions are available on this CPU... $ECHO_C" >&6; }
- if test "$cross_compiling" = yes; then
- ac_cv_cpu_has_sse2=no
-else
- cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h. */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h. */
-
- int main() {
- unsigned int ax, bx, cx, dx, func;
- func = 1U;
- __asm__ __volatile__ (
- "pushl %%ebx\n\t" /* don't clobber ebx */
- "cpuid\n\t"
- "movl %%ebx, %1\n\t"
- "popl %%ebx"
- : "=a" (ax), "=r" (bx), "=c" (cx), "=d" (dx)
- : "a" (func)
- : "cc" );
- if ((dx & (1U << 25)) && (dx & (1U << 26)))
- return 0;
- else
- return 1;
- }
-
-_ACEOF
-rm -f conftest$ac_exeext
-if { (ac_try="$ac_link"
-case "(($ac_try" in
- *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
- *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
- (eval "$ac_link") 2>&5
- ac_status=$?
- echo "$as_me:$LINENO: \$? = $ac_status" >&5
- (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
- { (case "(($ac_try" in
- *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
- *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
- (eval "$ac_try") 2>&5
- ac_status=$?
- echo "$as_me:$LINENO: \$? = $ac_status" >&5
- (exit $ac_status); }; }; then
- ac_cv_cpu_has_sse2=yes
-else
- echo "$as_me: program exited with status $ac_status" >&5
-echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-( exit $ac_status )
-ac_cv_cpu_has_sse2=no
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
-fi
-
-
- { echo "$as_me:$LINENO: result: $ac_cv_cpu_has_sse2" >&5
-echo "${ECHO_T}$ac_cv_cpu_has_sse2" >&6; }
-
- # determine whether gcc accepts options to turn on SSE2
- { echo "$as_me:$LINENO: checking whether $CC accepts -msse2 -mfpmath=sse" >&5
-echo $ECHO_N "checking whether $CC accepts -msse2 -mfpmath=sse... $ECHO_C" >&6; }
- ac_save_cc="$CC"
- CC="$CC -msse2 -mfpmath=sse"
- if test "$cross_compiling" = yes; then
- ac_cv_msse2_ok=no
-else
- cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h. */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h. */
-int main() { return 0; }
-_ACEOF
-rm -f conftest$ac_exeext
-if { (ac_try="$ac_link"
-case "(($ac_try" in
- *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
- *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
- (eval "$ac_link") 2>&5
- ac_status=$?
- echo "$as_me:$LINENO: \$? = $ac_status" >&5
- (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
- { (case "(($ac_try" in
- *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
- *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
- (eval "$ac_try") 2>&5
- ac_status=$?
- echo "$as_me:$LINENO: \$? = $ac_status" >&5
- (exit $ac_status); }; }; then
- ac_cv_msse2_ok=yes
-else
- echo "$as_me: program exited with status $ac_status" >&5
-echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-( exit $ac_status )
-ac_cv_msse2_ok=no
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
-fi
-
-
- CC="$ac_save_cc"
- { echo "$as_me:$LINENO: result: $ac_cv_msse2_ok" >&5
-echo "${ECHO_T}$ac_cv_msse2_ok" >&6; }
-
- if test $ac_cv_cpu_has_sse2 = yes && test $ac_cv_msse2_ok = yes
- then
- BASECFLAGS="$BASECFLAGS -msse2 -mfpmath=sse"
- else
- # SSE2 doesn't appear to be available. Check that it's okay
- # to use gcc inline assembler to get and set x87 control word
-
-cat >>confdefs.h <<\_ACEOF
-#define USING_X87_FPU 1
-_ACEOF
-
- { echo "$as_me:$LINENO: checking whether we can use gcc inline assembler to get and set x87 control word" >&5
+ # Check that it's okay to use gcc inline assembler to get and set
+ # x87 control word
+ { echo "$as_me:$LINENO: checking whether we can use gcc inline assembler to get and set x87 control word" >&5
echo $ECHO_N "checking whether we can use gcc inline assembler to get and set x87 control word... $ECHO_C" >&6; }
- cat >conftest.$ac_ext <<_ACEOF
+ cat >conftest.$ac_ext <<_ACEOF
/* confdefs.h. */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
main ()
{
- unsigned short cw;
- __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
- __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
+ unsigned short cw;
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
+ __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
;
return 0;
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
- { echo "$as_me:$LINENO: result: $have_gcc_asm_for_x87" >&5
+ { echo "$as_me:$LINENO: result: $have_gcc_asm_for_x87" >&5
echo "${ECHO_T}$have_gcc_asm_for_x87" >&6; }
- if test "$have_gcc_asm_for_x87" = yes
- then
+ if test "$have_gcc_asm_for_x87" = yes
+ then
cat >>confdefs.h <<\_ACEOF
#define HAVE_GCC_ASM_FOR_X87 1
_ACEOF
- fi
- fi
fi
fi
in ARM mixed-endian order (byte order 45670123)])
fi
-# David Gay's code in Python/dtoa.c requires that the FPU uses 53-bit
-# rounding; this is a particular problem on x86, where the x87 FPU has
-# a default rounding precision of 64 bits. For gcc/x86, we try to fix
-# this by:
-#
-# (1) using the SSE2 instruction set when available (it usually is
-# on modern machines)
-# (2) using inline assembler to get and set the x87 FPU control word
-# otherwise.
-#
-# On AMD64 (aka x86-64), gcc automatically enables use of SSE2
-# instructions, so we don't bother trying to detect.
-
+# The short float repr introduced in Python 3.1 requires the
+# correctly-rounded string <-> double conversion functions from
+# Python/dtoa.c, which in turn require that the FPU uses 53-bit
+# rounding; this is a problem on x86, where the x87 FPU has a default
+# rounding precision of 64 bits. For gcc/x86, we try to fix this by
+# using inline assembler to get and set the x87 FPU control word.
if test "$GCC" = yes && test -n "`$CC -dM -E - </dev/null | grep i386`"
then
- # determine whether we're already using the SSE2 instruction set for math
- # (e.g., this is true by default on OS X/x86)
- AC_MSG_CHECKING(whether SSE2 instructions are already enabled for math)
- if test -n "`$CC -dM -E - </dev/null | grep __SSE2_MATH__`"
- then
- ac_sse2_enabled=yes
- else
- ac_sse2_enabled=no
- fi
- AC_MSG_RESULT($ac_sse2_enabled)
-
- # if we're not using SSE2 already, we need to either enable it
- # (when available), or use inline assembler to get and set the
- # 387 control word.
- if test $ac_sse2_enabled = no
+ # Check that it's okay to use gcc inline assembler to get and set
+ # x87 control word. It should be, but you never know...
+ AC_MSG_CHECKING(whether we can use gcc inline assembler to get and set x87 control word)
+ AC_TRY_COMPILE([], [
+ unsigned short cw;
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
+ __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
+ ],
+ [have_gcc_asm_for_x87=yes], [have_gcc_asm_for_x87=no])
+ AC_MSG_RESULT($have_gcc_asm_for_x87)
+ if test "$have_gcc_asm_for_x87" = yes
then
- # Check cpuid for SSE2 availability. Bits 25 and 26 of edx tell
- # us about SSE and SSE2 respectively.
- AC_MSG_CHECKING(whether SSE2 instructions are available on this CPU)
- AC_TRY_RUN([
- int main() {
- unsigned int ax, bx, cx, dx, func;
- func = 1U;
- __asm__ __volatile__ (
- "pushl %%ebx\n\t" /* don't clobber ebx */
- "cpuid\n\t"
- "movl %%ebx, %1\n\t"
- "popl %%ebx"
- : "=a" (ax), "=r" (bx), "=c" (cx), "=d" (dx)
- : "a" (func)
- : "cc" );
- if ((dx & (1U << 25)) && (dx & (1U << 26)))
- return 0;
- else
- return 1;
- }
- ],
- ac_cv_cpu_has_sse2=yes,
- ac_cv_cpu_has_sse2=no,
- ac_cv_cpu_has_sse2=no)
- AC_MSG_RESULT($ac_cv_cpu_has_sse2)
-
- # determine whether gcc accepts options to turn on SSE2
- AC_MSG_CHECKING(whether $CC accepts -msse2 -mfpmath=sse)
- ac_save_cc="$CC"
- CC="$CC -msse2 -mfpmath=sse"
- AC_TRY_RUN([int main() { return 0; }],
- ac_cv_msse2_ok=yes,
- ac_cv_msse2_ok=no,
- ac_cv_msse2_ok=no)
- CC="$ac_save_cc"
- AC_MSG_RESULT($ac_cv_msse2_ok)
-
- if test $ac_cv_cpu_has_sse2 = yes && test $ac_cv_msse2_ok = yes
- then
- BASECFLAGS="$BASECFLAGS -msse2 -mfpmath=sse"
- else
- # SSE2 doesn't appear to be available. Check that it's okay
- # to use gcc inline assembler to get and set x87 control word
- AC_DEFINE(USING_X87_FPU, 1,
- [Define on x86 hardware if the x87 FPU is being used
- for floating-point arithmetic])
- AC_MSG_CHECKING(whether we can use gcc inline assembler to get and set x87 control word)
- AC_TRY_COMPILE([], [
- unsigned short cw;
- __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
- __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
- ],
- [have_gcc_asm_for_x87=yes], [have_gcc_asm_for_x87=no])
- AC_MSG_RESULT($have_gcc_asm_for_x87)
- if test "$have_gcc_asm_for_x87" = yes
- then
- AC_DEFINE(HAVE_GCC_ASM_FOR_X87, 1,
- [Define if we can use gcc inline assembler to get and set x87 control word])
- fi
- fi
+ AC_DEFINE(HAVE_GCC_ASM_FOR_X87, 1,
+ [Define if we can use gcc inline assembler to get and set x87 control word])
fi
fi
/* Define if you want to use computed gotos in ceval.c. */
#undef USE_COMPUTED_GOTOS
-/* Define on x86 hardware if the x87 FPU is being used for floating-point
- arithmetic */
-#undef USING_X87_FPU
-
/* Define if a va_list is an array of some kind */
#undef VA_LIST_IS_ARRAY
projects / python / commitdiff