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Fix csin, csinh, ccos, ccosh missing underflows (bug 15405)


Bug 15405 is missing underflow exceptions from csin, csinh, ccos and
ccosh when one or both parts of the result underflow but this does not
raise the underflow flag because the calculation that produced the
tiny result was an exact multiplication (although the exact
mathematical result is not exactly representable).  This patch fixes
the missing exceptions in the same way they were fixed for cexp (bug
14478).  (ccos is implemented in terms of ccosh so doesn't need a
separate fix.)

Tested x86_64 and x86 (no ulps changes needed).

2013-04-26  Joseph Myers  <joseph@codesourcery.com>

	[BZ #15405]
	* math/s_ccosh.c (__ccosh): Ensure underflow exception occurs for
	underflowed result.
	* math/s_ccoshf.c (__ccoshf): Likewise.
	* math/s_ccoshl.c (__ccoshl): Likewise.
	* math/s_csin.c (__csin): Likewise.
	* math/s_csinf.c (__csinf): Likewise.
	* math/s_csinh.c (__csinh): Likewise.
	* math/s_csinhf.c (__csinhf): Likewise.
	* math/s_csinhl.c (__csinhl): Likewise.
	* math/s_csinl.c (__csinl): Likewise.
	* math/libm-test.inc (ccos_test): Add more tests.
	(ccosh_test): Likewise.
	(csin_test): Likewise.
	(csinh_test): Likewise.

diff --git a/math/libm-test.inc b/math/libm-test.inc
index eb9fa71..a3d7731 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -4570,6 +4570,9 @@ ccos_test (void)
   TEST_c_c (ccos, 0x1p-16434L, 22730, plus_infty, -1.217853148905605987081057582351152052687e4924L, OVERFLOW_EXCEPTION);
 #endif
 
+  TEST_c_c (ccos, min_subnorm_value * 0x1p120, 0x1p-120, 1.0, -min_subnorm_value, UNDERFLOW_EXCEPTION);
+  TEST_c_c (ccos, 0x1p-120, min_subnorm_value * 0x1p120, 1.0, -min_subnorm_value, UNDERFLOW_EXCEPTION);
+
   END (ccos, complex);
 }
 
@@ -4670,6 +4673,9 @@ ccosh_test (void)
   TEST_c_c (ccosh, 22730, 0x1p-16434L, plus_infty, 1.217853148905605987081057582351152052687e4924L, OVERFLOW_EXCEPTION);
 #endif
 
+  TEST_c_c (ccosh, min_subnorm_value * 0x1p120, 0x1p-120, 1.0, min_subnorm_value, UNDERFLOW_EXCEPTION);
+  TEST_c_c (ccosh, 0x1p-120, min_subnorm_value * 0x1p120, 1.0, min_subnorm_value, UNDERFLOW_EXCEPTION);
+
   END (ccosh, complex);
 }
 
@@ -5898,6 +5904,9 @@ csin_test (void)
   TEST_c_c (csin, 0x1p-16434L, 22730, 1.217853148905605987081057582351152052687e4924L, plus_infty, OVERFLOW_EXCEPTION);
 #endif
 
+  TEST_c_c (csin, min_subnorm_value, min_value, min_subnorm_value, min_value, UNDERFLOW_EXCEPTION);
+  TEST_c_c (csin, min_value, min_subnorm_value, min_value, min_subnorm_value, UNDERFLOW_EXCEPTION);
+
   END (csin, complex);
 }
 
@@ -5997,6 +6006,9 @@ csinh_test (void)
   TEST_c_c (csinh, 22730, 0x1p-16434L, plus_infty, 1.217853148905605987081057582351152052687e4924L, OVERFLOW_EXCEPTION);
 #endif
 
+  TEST_c_c (csinh, min_subnorm_value, min_value, min_subnorm_value, min_value, UNDERFLOW_EXCEPTION);
+  TEST_c_c (csinh, min_value, min_subnorm_value, min_value, min_subnorm_value, UNDERFLOW_EXCEPTION);
+
   END (csinh, complex);
 }
 
diff --git a/math/s_ccosh.c b/math/s_ccosh.c
index 2c05b63..05b146e 100644
--- a/math/s_ccosh.c
+++ b/math/s_ccosh.c
@@ -82,6 +82,19 @@ __ccosh (__complex__ double x)
 	      __real__ retval = __ieee754_cosh (__real__ x) * cosix;
 	      __imag__ retval = __ieee754_sinh (__real__ x) * sinix;
 	    }
+
+	  if (fabs (__real__ retval) < DBL_MIN)
+	    {
+	      volatile double force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabs (__imag__ retval) < DBL_MIN)
+	    {
+	      volatile double force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_ccoshf.c b/math/s_ccoshf.c
index de7e7d3..62bf83c 100644
--- a/math/s_ccoshf.c
+++ b/math/s_ccoshf.c
@@ -82,6 +82,19 @@ __ccoshf (__complex__ float x)
 	      __real__ retval = __ieee754_coshf (__real__ x) * cosix;
 	      __imag__ retval = __ieee754_sinhf (__real__ x) * sinix;
 	    }
+
+	  if (fabsf (__real__ retval) < FLT_MIN)
+	    {
+	      volatile float force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabsf (__imag__ retval) < FLT_MIN)
+	    {
+	      volatile float force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_ccoshl.c b/math/s_ccoshl.c
index 4bbd311..18d3df0 100644
--- a/math/s_ccoshl.c
+++ b/math/s_ccoshl.c
@@ -82,6 +82,19 @@ __ccoshl (__complex__ long double x)
 	      __real__ retval = __ieee754_coshl (__real__ x) * cosix;
 	      __imag__ retval = __ieee754_sinhl (__real__ x) * sinix;
 	    }
+
+	  if (fabsl (__real__ retval) < LDBL_MIN)
+	    {
+	      volatile long double force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabsl (__imag__ retval) < LDBL_MIN)
+	    {
+	      volatile long double force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_csin.c b/math/s_csin.c
index cc1c9cd..6d28e4c 100644
--- a/math/s_csin.c
+++ b/math/s_csin.c
@@ -88,6 +88,19 @@ __csin (__complex__ double x)
 
 	  if (negate)
 	    __real__ retval = -__real__ retval;
+
+	  if (fabs (__real__ retval) < DBL_MIN)
+	    {
+	      volatile double force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabs (__imag__ retval) < DBL_MIN)
+	    {
+	      volatile double force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_csinf.c b/math/s_csinf.c
index 92b858a..a3dcf9d 100644
--- a/math/s_csinf.c
+++ b/math/s_csinf.c
@@ -88,6 +88,19 @@ __csinf (__complex__ float x)
 
 	  if (negate)
 	    __real__ retval = -__real__ retval;
+
+	  if (fabsf (__real__ retval) < FLT_MIN)
+	    {
+	      volatile float force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabsf (__imag__ retval) < FLT_MIN)
+	    {
+	      volatile float force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_csinh.c b/math/s_csinh.c
index be3c6bb..5a98f67 100644
--- a/math/s_csinh.c
+++ b/math/s_csinh.c
@@ -88,6 +88,19 @@ __csinh (__complex__ double x)
 
 	  if (negate)
 	    __real__ retval = -__real__ retval;
+
+	  if (fabs (__real__ retval) < DBL_MIN)
+	    {
+	      volatile double force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabs (__imag__ retval) < DBL_MIN)
+	    {
+	      volatile double force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_csinhf.c b/math/s_csinhf.c
index 6c58c1d..3658805 100644
--- a/math/s_csinhf.c
+++ b/math/s_csinhf.c
@@ -88,6 +88,19 @@ __csinhf (__complex__ float x)
 
 	  if (negate)
 	    __real__ retval = -__real__ retval;
+
+	  if (fabsf (__real__ retval) < FLT_MIN)
+	    {
+	      volatile float force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabsf (__imag__ retval) < FLT_MIN)
+	    {
+	      volatile float force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_csinhl.c b/math/s_csinhl.c
index 8acf6de..54a13fd 100644
--- a/math/s_csinhl.c
+++ b/math/s_csinhl.c
@@ -88,6 +88,19 @@ __csinhl (__complex__ long double x)
 
 	  if (negate)
 	    __real__ retval = -__real__ retval;
+
+	  if (fabsl (__real__ retval) < LDBL_MIN)
+	    {
+	      volatile long double force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabsl (__imag__ retval) < LDBL_MIN)
+	    {
+	      volatile long double force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{
diff --git a/math/s_csinl.c b/math/s_csinl.c
index 6b3c1ea..4d6ce3d 100644
--- a/math/s_csinl.c
+++ b/math/s_csinl.c
@@ -88,6 +88,19 @@ __csinl (__complex__ long double x)
 
 	  if (negate)
 	    __real__ retval = -__real__ retval;
+
+	  if (fabsl (__real__ retval) < LDBL_MIN)
+	    {
+	      volatile long double force_underflow
+		= __real__ retval * __real__ retval;
+	      (void) force_underflow;
+	    }
+	  if (fabsl (__imag__ retval) < LDBL_MIN)
+	    {
+	      volatile long double force_underflow
+		= __imag__ retval * __imag__ retval;
+	      (void) force_underflow;
+	    }
 	}
       else
 	{

-- 
Joseph S. Myers
joseph@codesourcery.com


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