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authorJoseph Myers <joseph@codesourcery.com>2015-09-18 20:00:48 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-09-18 20:00:48 +0000
commitc8235dda728c4452f57c4c0d1bccc4e9a67da80c (patch)
treeae521c94b4648e089ee442cf8991963e7ffd97fe /ChangeLog
parentfe8c2b33aed067282ecac0cc3fdff1feef88548b (diff)
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Avoid excess range overflowing results from cosh, sinh, lgamma (bug 18980).
Various i386 libm functions return values with excess range and
precision; Wilco Dijkstra's patches to make isfinite etc. expand
inline cause this pre-existing issue to result in test failures (when
e.g. a result that overflows float but not long double gets counted as
overflowing for some purposes but not others).

This patch addresses those cases arising from functions defined in C,
adding a math_narrow_eval macro that forces values to memory to
eliminate excess precision if FLT_EVAL_METHOD indicates this is
needed, and is a no-op otherwise.  I'll convert existing uses of
volatile and asm for this purpose to use the new macro later, once
i386 has clean test results again (which requires fixes for .S files
as well).

Tested for x86_64 and x86.  Committed.

	[BZ #18980]
	* sysdeps/generic/math_private.h: Include <float.h>.
	(math_narrow_eval): New macro.
	[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
	* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Use
	math_narrow_eval on overflowing return value.
	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r):
	Likewise.
	* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
	* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Likewise.
	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r):
	Likewise.
	* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
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+2015-09-18  Joseph Myers  <joseph@codesourcery.com>
+
+	[BZ #18980]
+	* sysdeps/generic/math_private.h: Include <float.h>.
+	(math_narrow_eval): New macro.
+	[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
+	* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Use
+	math_narrow_eval on overflowing return value.
+	* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r):
+	Likewise.
+	* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
+	* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Likewise.
+	* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r):
+	Likewise.
+	* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
+
 2015-09-18  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* include/math.h: Remove __isinf_ns, __isinf_nsf, __isinf_nsl.