Author: Armin Rigo <[email protected]>
Branch:
Changeset: r49031:df7f0844e6b4
Date: 2011-11-09 18:13 +0100
http://bitbucket.org/pypy/pypy/changeset/df7f0844e6b4/
Log: Tweak for the common case: use isfinite() more often, and only fall
back to checking isnan() and isinf() if it returns False.
diff --git a/pypy/rpython/lltypesystem/module/ll_math.py
b/pypy/rpython/lltypesystem/module/ll_math.py
--- a/pypy/rpython/lltypesystem/module/ll_math.py
+++ b/pypy/rpython/lltypesystem/module/ll_math.py
@@ -136,10 +136,12 @@
Windows, FreeBSD and alpha Tru64 are amongst platforms that don't
always follow C99.
"""
- if isnan(x) or isnan(y):
+ if isnan(x):
return NAN
- if isinf(y):
+ if not isfinite(y):
+ if isnan(y):
+ return NAN
if isinf(x):
if math_copysign(1.0, x) == 1.0:
# atan2(+-inf, +inf) == +-pi/4
@@ -168,7 +170,7 @@
def ll_math_frexp(x):
# deal with special cases directly, to sidestep platform differences
- if isnan(x) or isinf(x) or not x:
+ if not isfinite(x) or not x:
mantissa = x
exponent = 0
else:
@@ -185,7 +187,7 @@
INT_MIN = int(-2**31)
def ll_math_ldexp(x, exp):
- if x == 0.0 or isinf(x) or isnan(x):
+ if x == 0.0 or not isfinite(x):
return x # NaNs, zeros and infinities are returned unchanged
if exp > INT_MAX:
# overflow (64-bit platforms only)
@@ -209,10 +211,11 @@
def ll_math_modf(x):
# some platforms don't do the right thing for NaNs and
# infinities, so we take care of special cases directly.
- if isinf(x):
- return (math_copysign(0.0, x), x)
- elif isnan(x):
- return (x, x)
+ if not isfinite(x):
+ if isnan(x):
+ return (x, x)
+ else: # isinf(x)
+ return (math_copysign(0.0, x), x)
intpart_p = lltype.malloc(rffi.DOUBLEP.TO, 1, flavor='raw')
try:
fracpart = math_modf(x, intpart_p)
@@ -250,16 +253,17 @@
_error_reset()
r = math_hypot(x, y)
errno = rposix.get_errno()
- if isnan(r):
- if isnan(x) or isnan(y):
- errno = 0
- else:
- errno = EDOM
- elif isinf(r):
- if isinf(x) or isnan(x) or isinf(y) or isnan(y):
- errno = 0
- else:
- errno = ERANGE
+ if not isfinite(r):
+ if isnan(r):
+ if isnan(x) or isnan(y):
+ errno = 0
+ else:
+ errno = EDOM
+ else: # isinf(r)
+ if isfinite(x) and isfinite(y):
+ errno = ERANGE
+ else:
+ errno = 0
if errno:
_likely_raise(errno, r)
return r
@@ -269,30 +273,30 @@
# deal directly with IEEE specials, to cope with problems on various
# platforms whose semantics don't exactly match C99
- if isnan(x):
- if y == 0.0:
- return 1.0 # NaN**0 = 1
- return x
-
- elif isnan(y):
+ if isnan(y):
if x == 1.0:
return 1.0 # 1**Nan = 1
return y
- elif isinf(x):
- odd_y = not isinf(y) and math_fmod(math_fabs(y), 2.0) == 1.0
- if y > 0.0:
- if odd_y:
- return x
- return math_fabs(x)
- elif y == 0.0:
- return 1.0
- else: # y < 0.0
- if odd_y:
- return math_copysign(0.0, x)
- return 0.0
+ if not isfinite(x):
+ if isnan(x):
+ if y == 0.0:
+ return 1.0 # NaN**0 = 1
+ return x
+ else: # isinf(x)
+ odd_y = not isinf(y) and math_fmod(math_fabs(y), 2.0) == 1.0
+ if y > 0.0:
+ if odd_y:
+ return x
+ return math_fabs(x)
+ elif y == 0.0:
+ return 1.0
+ else: # y < 0.0
+ if odd_y:
+ return math_copysign(0.0, x)
+ return 0.0
- elif isinf(y):
+ if isinf(y):
if math_fabs(x) == 1.0:
return 1.0
elif y > 0.0 and math_fabs(x) > 1.0:
@@ -307,17 +311,18 @@
_error_reset()
r = math_pow(x, y)
errno = rposix.get_errno()
- if isnan(r):
- # a NaN result should arise only from (-ve)**(finite non-integer)
- errno = EDOM
- elif isinf(r):
- # an infinite result here arises either from:
- # (A) (+/-0.)**negative (-> divide-by-zero)
- # (B) overflow of x**y with x and y finite
- if x == 0.0:
+ if not isfinite(r):
+ if isnan(r):
+ # a NaN result should arise only from (-ve)**(finite non-integer)
errno = EDOM
- else:
- errno = ERANGE
+ else: # isinf(r)
+ # an infinite result here arises either from:
+ # (A) (+/-0.)**negative (-> divide-by-zero)
+ # (B) overflow of x**y with x and y finite
+ if x == 0.0:
+ errno = EDOM
+ else:
+ errno = ERANGE
if errno:
_likely_raise(errno, r)
return r
@@ -366,18 +371,19 @@
r = c_func(x)
# Error checking fun. Copied from CPython 2.6
errno = rposix.get_errno()
- if isnan(r):
- if isnan(x):
- errno = 0
- else:
- errno = EDOM
- elif isinf(r):
- if isinf(x) or isnan(x):
- errno = 0
- elif can_overflow:
- errno = ERANGE
- else:
- errno = EDOM
+ if not isfinite(r):
+ if isnan(r):
+ if isnan(x):
+ errno = 0
+ else:
+ errno = EDOM
+ else: # isinf(r)
+ if not isfinite(x):
+ errno = 0
+ elif can_overflow:
+ errno = ERANGE
+ else:
+ errno = EDOM
if errno:
_likely_raise(errno, r)
return r
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