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authorJoseph Myers <joseph@codesourcery.com>2016-10-11 00:50:43 +0000
committerJoseph Myers <joseph@codesourcery.com>2016-10-11 00:50:43 +0000
commit4d5940f0151241b73c6c0c1eb290462eb9c279b0 (patch)
treef0929fb2863a195e3052febb3d9504125cdb7391 /math/s_ccosh_template.c
parent352db0bd059df1ad2da5d22e6ea3fd3e4f2ce236 (diff)
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Avoid M_NAN + M_NAN in complex functions.
Some libm complex functions have code that computes M_NAN + M_NAN.
This is nonsensical; it's just equivalent to M_NAN, since it's a quiet
NaN (and the comments suggesting this raises an exception are
similarly wrong).  This patch changes the code just to use M_NAN (and
removes the bogus comments).  (Preferably, code should either
propagate an input NaN or do a computation that raises "invalid" and
generates a default NaN at the same time.  There are various cases,
however, that currently raise "invalid" even for NaN inputs; I think
those are cases where "invalid" is optional in ISO C so a change to
whether it's raised would be OK, but they would still need more
careful consideration than the cases where such issues do not arise.)

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	* math/s_ccosh_template.c (M_DECL_FUNC (__ccosh)): Use M_NAN
	instead of M_NAN + M_NAN.
	* math/s_csinh_template.c (M_DECL_FUNC (__csinh)): Likewise.
Diffstat (limited to 'math/s_ccosh_template.c')
-rw-r--r--math/s_ccosh_template.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/math/s_ccosh_template.c b/math/s_ccosh_template.c
index 68de41d2da..7fea5c9f57 100644
--- a/math/s_ccosh_template.c
+++ b/math/s_ccosh_template.c
@@ -88,7 +88,7 @@ M_DECL_FUNC (__ccosh) (CFLOAT x)
       else
 	{
 	  __imag__ retval = __real__ x == 0 ? 0 : M_NAN;
-	  __real__ retval = M_NAN + M_NAN;
+	  __real__ retval = M_NAN;
 
 	  if (icls == FP_INFINITE)
 	    feraiseexcept (FE_INVALID);
@@ -124,9 +124,8 @@ M_DECL_FUNC (__ccosh) (CFLOAT x)
 	}
       else
 	{
-	  /* The addition raises the invalid exception.  */
 	  __real__ retval = M_HUGE_VAL;
-	  __imag__ retval = M_NAN + M_NAN;
+	  __imag__ retval = M_NAN;
 
 	  if (icls == FP_INFINITE)
 	    feraiseexcept (FE_INVALID);