Refactor code forcing underflow exceptions.

Various floating-point functions have code to force underflow
exceptions if a tiny result was computed in a way that might not have
resulted in such exceptions even though the result is inexact.  This
typically uses math_force_eval to ensure that the underflowing
expression is evaluated, but sometimes uses volatile.

This patch refactors such code to use three new macros
math_check_force_underflow, math_check_force_underflow_nonneg and
math_check_force_underflow_complex (which in turn use
math_force_eval).  In the limited number of cases not suited to a
simple conversion to these macros, existing uses of volatile are
changed to use math_force_eval instead.  The converted code does not
always execute exactly the same sequence of operations as the original
code, but the overall effects should be the same.

Tested for x86_64, x86, mips64 and powerpc.

	* sysdeps/generic/math_private.h (fabs_tg): New macro.
	(min_of_type): Likewise.
	(math_check_force_underflow): Likewise.
	(math_check_force_underflow_nonneg): Likewise.
	(math_check_force_underflow_complex): Likewise.
	* math/e_exp2l.c (__ieee754_exp2l): Use
	math_check_force_underflow_nonneg.
	* math/k_casinh.c (__kernel_casinh): Likewise.
	* math/k_casinhf.c (__kernel_casinhf): Likewise.
	* math/k_casinhl.c (__kernel_casinhl): Likewise.
	* math/s_catan.c (__catan): Use
	math_check_force_underflow_complex.
	* math/s_catanf.c (__catanf): Likewise.
	* math/s_catanh.c (__catanh): Likewise.
	* math/s_catanhf.c (__catanhf): Likewise.
	* math/s_catanhl.c (__catanhl): Likewise.
	* math/s_catanl.c (__catanl): Likewise.
	* math/s_ccosh.c (__ccosh): Likewise.
	* math/s_ccoshf.c (__ccoshf): Likewise.
	* math/s_ccoshl.c (__ccoshl): Likewise.
	* math/s_cexp.c (__cexp): Likewise.
	* math/s_cexpf.c (__cexpf): Likewise.
	* math/s_cexpl.c (__cexpl): Likewise.
	* math/s_clog.c (__clog): Use math_check_force_underflow_nonneg.
	* math/s_clog10.c (__clog10): Likewise.
	* math/s_clog10f.c (__clog10f): Likewise.
	* math/s_clog10l.c (__clog10l): Likewise.
	* math/s_clogf.c (__clogf): Likewise.
	* math/s_clogl.c (__clogl): Likewise.
	* math/s_csin.c (__csin): Use math_check_force_underflow_complex.
	* 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/s_csqrt.c (__csqrt): Use math_check_force_underflow.
	* math/s_csqrtf.c (__csqrtf): Likewise.
	* math/s_csqrtl.c (__csqrtl): Likewise.
	* math/s_ctan.c (__ctan): Use math_check_force_underflow_complex.
	* math/s_ctanf.c (__ctanf): Likewise.
	* math/s_ctanh.c (__ctanh): Likewise.
	* math/s_ctanhf.c (__ctanhf): Likewise.
	* math/s_ctanhl.c (__ctanhl): Likewise.
	* math/s_ctanl.c (__ctanl): Likewise.
	* stdlib/strtod_l.c (round_and_return): Use math_force_eval
	instead of volatile.
	* sysdeps/ieee754/dbl-64/e_asin.c (__ieee754_asin): Use
	math_check_force_underflow.
	* sysdeps/ieee754/dbl-64/e_atanh.c (__ieee754_atanh): Likewise.
	* sysdeps/ieee754/dbl-64/e_exp.c (__ieee754_exp): Do not use
	volatile when forcing underflow.
	* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/dbl-64/e_gamma_r.c (__ieee754_gamma_r):
	Likewise.
	* sysdeps/ieee754/dbl-64/e_j1.c (__ieee754_j1): Use
	math_check_force_underflow.
	* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Likewise.
	* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
	* sysdeps/ieee754/dbl-64/s_asinh.c (__asinh): Likewise.
	* sysdeps/ieee754/dbl-64/s_atan.c (atan): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/dbl-64/s_erf.c (__erf): Use
	math_check_force_underflow.
	* sysdeps/ieee754/dbl-64/s_expm1.c (__expm1): Likewise.
	* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Use math_force_eval
	instead of volatile.
	* sysdeps/ieee754/dbl-64/s_log1p.c (__log1p): Use
	math_check_force_underflow.
	* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Likewise.
	* sysdeps/ieee754/dbl-64/s_tan.c (tan): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/dbl-64/s_tanh.c (__tanh): Use
	math_check_force_underflow.
	* sysdeps/ieee754/flt-32/e_asinf.c (__ieee754_asinf): Likewise.
	* sysdeps/ieee754/flt-32/e_atanhf.c (__ieee754_atanhf): Likewise.
	* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c (__ieee754_gammaf_r):
	Likewise.
	* sysdeps/ieee754/flt-32/e_j1f.c (__ieee754_j1f): Use
	math_check_force_underflow.
	* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
	* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
	* sysdeps/ieee754/flt-32/k_sinf.c (__kernel_sinf): Likewise.
	* sysdeps/ieee754/flt-32/k_tanf.c (__kernel_tanf): Likewise.
	* sysdeps/ieee754/flt-32/s_asinhf.c (__asinhf): Likewise.
	* sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Likewise.
	* sysdeps/ieee754/flt-32/s_erff.c (__erff): Likewise.
	* sysdeps/ieee754/flt-32/s_expm1f.c (__expm1f): Likewise.
	* sysdeps/ieee754/flt-32/s_log1pf.c (__log1pf): Likewise.
	* sysdeps/ieee754/flt-32/s_tanhf.c (__tanhf): Likewise.
	* sysdeps/ieee754/ldbl-128/e_asinl.c (__ieee754_asinl): Likewise.
	* sysdeps/ieee754/ldbl-128/e_atanhl.c (__ieee754_atanhl):
	Likewise.
	* sysdeps/ieee754/ldbl-128/e_expl.c (__ieee754_expl): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/ldbl-128/e_gammal_r.c (__ieee754_gammal_r):
	Likewise.
	* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): Use
	math_check_force_underflow.
	* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
	* sysdeps/ieee754/ldbl-128/e_sinhl.c (__ieee754_sinhl): Likewise.
	* sysdeps/ieee754/ldbl-128/k_sincosl.c (__kernel_sincosl):
	Likewise.
	* sysdeps/ieee754/ldbl-128/k_sinl.c (__kernel_sinl): Likewise.
	* sysdeps/ieee754/ldbl-128/k_tanl.c (__kernel_tanl): Likewise.
	* sysdeps/ieee754/ldbl-128/s_asinhl.c (__asinhl): Likewise.
	* sysdeps/ieee754/ldbl-128/s_atanl.c (__atanl): Likewise.
	* sysdeps/ieee754/ldbl-128/s_erfl.c (__erfl): Likewise.
	* sysdeps/ieee754/ldbl-128/s_expm1l.c (__expm1l): Likewise.
	* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Use math_force_eval
	instead of volatile.
	* sysdeps/ieee754/ldbl-128/s_log1pl.c (__log1pl): Use
	math_check_force_underflow.
	* sysdeps/ieee754/ldbl-128/s_tanhl.c (__tanhl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_asinl.c (__ieee754_asinl): Use
	math_check_force_underflow.
	* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c (__ieee754_atanhl):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
	Use math_check_force_underflow_nonneg.
	* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Use
	math_check_force_underflow.
	* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c (__ieee754_sinhl):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c (__kernel_sincosl):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/k_sinl.c (__kernel_sinl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/k_tanl.c (__kernel_tanl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_atanl.c (__atanl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_erfl.c (__erfl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Likewise.
	* sysdeps/ieee754/ldbl-96/e_asinl.c (__ieee754_asinl): Likewise.
	* sysdeps/ieee754/ldbl-96/e_atanhl.c (__ieee754_atanhl): Likewise.
	* sysdeps/ieee754/ldbl-96/e_gammal_r.c (__ieee754_gammal_r): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/ldbl-96/e_j1l.c (__ieee754_j1l): Use
	math_check_force_underflow.
	* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
	* sysdeps/ieee754/ldbl-96/e_sinhl.c (__ieee754_sinhl): Likewise.
	* sysdeps/ieee754/ldbl-96/k_sinl.c (__kernel_sinl): Likewise.
	* sysdeps/ieee754/ldbl-96/k_tanl.c (__kernel_tanl): Use
	math_check_force_underflow_nonneg.
	* sysdeps/ieee754/ldbl-96/s_asinhl.c (__asinhl): Use
	math_check_force_underflow.
	* sysdeps/ieee754/ldbl-96/s_erfl.c (__erfl): Likewise.
	* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Use math_force_eval
	instead of volatile.
	* sysdeps/ieee754/ldbl-96/s_tanhl.c (__tanhl): Use
	math_check_force_underflow.

73 files changed, 81 insertions, 353 deletions

diff --git a/sysdeps/ieee754/dbl-64/e_asin.c b/sysdeps/ieee754/dbl-64/e_asin.c
index a7684d1078..214a61211a 100644
--- a/sysdeps/ieee754/dbl-64/e_asin.c
+++ b/sysdeps/ieee754/dbl-64/e_asin.c
@@ -71,11 +71,7 @@ __ieee754_asin(double x){
 
   if (k < 0x3e500000)
     {
-      if (fabs (x) < DBL_MIN)
-	{
-	  double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       return x;  /* for x->0 => sin(x)=x */
     }
   /*----------------------2^-26 <= |x| < 2^ -3    -----------------*/
diff --git a/sysdeps/ieee754/dbl-64/e_atanh.c b/sysdeps/ieee754/dbl-64/e_atanh.c
index 6b00b800f2..f011e4c4eb 100644
--- a/sysdeps/ieee754/dbl-64/e_atanh.c
+++ b/sysdeps/ieee754/dbl-64/e_atanh.c
@@ -52,11 +52,7 @@ __ieee754_atanh (double x)
       if (__glibc_unlikely (xa < 0x1.0p-28))
 	{
 	  math_force_eval (huge + x);
-	  if (fabs (x) < DBL_MIN)
-	    {
-	      double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  return x;
 	}
 
diff --git a/sysdeps/ieee754/dbl-64/e_exp.c b/sysdeps/ieee754/dbl-64/e_exp.c
index bb76907f74..db7626844a 100644
--- a/sysdeps/ieee754/dbl-64/e_exp.c
+++ b/sysdeps/ieee754/dbl-64/e_exp.c
@@ -200,10 +200,7 @@ __ieee754_exp (double x)
       check_uflow_ret:
 	if (retval < DBL_MIN)
 	  {
-#if FLT_EVAL_METHOD != 0
-	    volatile
-#endif
-	      double force_underflow = tiny * tiny;
+	    double force_underflow = tiny * tiny;
 	    math_force_eval (force_underflow);
 	  }
 	if (retval == 0)
diff --git a/sysdeps/ieee754/dbl-64/e_exp2.c b/sysdeps/ieee754/dbl-64/e_exp2.c
index 01df62150d..48a7254086 100644
--- a/sysdeps/ieee754/dbl-64/e_exp2.c
+++ b/sysdeps/ieee754/dbl-64/e_exp2.c
@@ -122,11 +122,7 @@ __ieee754_exp2 (double x)
       else
 	{
 	  result *= scale_u.d;
-	  if (result < DBL_MIN)
-	    {
-	      double force_underflow = result * result;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow_nonneg (result);
 	  return result;
 	}
     }
diff --git a/sysdeps/ieee754/dbl-64/e_gamma_r.c b/sysdeps/ieee754/dbl-64/e_gamma_r.c
index d3fb8af97e..a09a3fc1f2 100644
--- a/sysdeps/ieee754/dbl-64/e_gamma_r.c
+++ b/sysdeps/ieee754/dbl-64/e_gamma_r.c
@@ -187,11 +187,7 @@ __ieee754_gamma_r (double x, int *signgamp)
 	      double tret = M_PI / (-x * sinpix
 				    * gamma_positive (-x, &exp2_adj));
 	      ret = __scalbn (tret, -exp2_adj);
-	      if (ret < DBL_MIN)
-		{
-		  double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (ret);
 	    }
 	}
       ret = math_narrow_eval (ret);
diff --git a/sysdeps/ieee754/dbl-64/e_j1.c b/sysdeps/ieee754/dbl-64/e_j1.c
index 26ffdfe282..7f80b3ced0 100644
--- a/sysdeps/ieee754/dbl-64/e_j1.c
+++ b/sysdeps/ieee754/dbl-64/e_j1.c
@@ -128,11 +128,7 @@ __ieee754_j1 (double x)
       if (huge + x > one)                 /* inexact if x!=0 necessary */
 	{
 	  double ret = 0.5 * x;
-	  if (fabs (ret) < DBL_MIN)
-	    {
-	      double force_underflow = ret * ret;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (ret);
 	  return ret;
 	}
     }
diff --git a/sysdeps/ieee754/dbl-64/e_jn.c b/sysdeps/ieee754/dbl-64/e_jn.c
index ccef2dcd80..d6ab0bced5 100644
--- a/sysdeps/ieee754/dbl-64/e_jn.c
+++ b/sysdeps/ieee754/dbl-64/e_jn.c
@@ -246,11 +246,8 @@ __ieee754_jn (int n, double x)
   }
   if (ret == 0)
     ret = __copysign (DBL_MIN, ret) * DBL_MIN;
-  else if (fabs (ret) < DBL_MIN)
-    {
-      double force_underflow = ret * ret;
-      math_force_eval (force_underflow);
-    }
+  else
+    math_check_force_underflow (ret);
   return ret;
 }
 strong_alias (__ieee754_jn, __jn_finite)
diff --git a/sysdeps/ieee754/dbl-64/e_sinh.c b/sysdeps/ieee754/dbl-64/e_sinh.c
index 291bfad0b3..8479bdd9b8 100644
--- a/sysdeps/ieee754/dbl-64/e_sinh.c
+++ b/sysdeps/ieee754/dbl-64/e_sinh.c
@@ -60,11 +60,7 @@ __ieee754_sinh (double x)
   if (ix < 0x40360000)                  /* |x|<22 */
     {
       if (__glibc_unlikely (ix < 0x3e300000)) {            /* |x|<2**-28 */
-	if (fabs (x) < DBL_MIN)
-	  {
-	    double force_underflow = x * x;
-	    math_force_eval (force_underflow);
-	  }
+	math_check_force_underflow (x);
 	if (shuge + x > one)
 	  return x;
 	/* sinh(tiny) = tiny with inexact */
diff --git a/sysdeps/ieee754/dbl-64/s_asinh.c b/sysdeps/ieee754/dbl-64/s_asinh.c
index ebe471015b..9193301b5e 100644
--- a/sysdeps/ieee754/dbl-64/s_asinh.c
+++ b/sysdeps/ieee754/dbl-64/s_asinh.c
@@ -39,11 +39,7 @@ __asinh (double x)
   ix = hx & 0x7fffffff;
   if (__glibc_unlikely (ix < 0x3e300000))                  /* |x|<2**-28 */
     {
-      if (fabs (x) < DBL_MIN)
-	{
-	  double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       if (huge + x > one)
 	return x;                       /* return x inexact except 0 */
     }
diff --git a/sysdeps/ieee754/dbl-64/s_atan.c b/sysdeps/ieee754/dbl-64/s_atan.c
index 5035ae87bc..5160cd1b66 100644
--- a/sysdeps/ieee754/dbl-64/s_atan.c
+++ b/sysdeps/ieee754/dbl-64/s_atan.c
@@ -90,11 +90,7 @@ atan (double x)
 	{
 	  if (u < A)
 	    {
-	      if (u < DBL_MIN)
-		{
-		  double force_underflow = x * x;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (u);
 	      return x;
 	    }
 	  else
diff --git a/sysdeps/ieee754/dbl-64/s_erf.c b/sysdeps/ieee754/dbl-64/s_erf.c
index 77cd50d935..e59f5f33ce 100644
--- a/sysdeps/ieee754/dbl-64/s_erf.c
+++ b/sysdeps/ieee754/dbl-64/s_erf.c
@@ -213,11 +213,7 @@ __erf (double x)
 	    {
 	      /* Avoid spurious underflow.  */
 	      double ret = 0.0625 * (16.0 * x + (16.0 * efx) * x);
-	      if (fabs (ret) < DBL_MIN)
-		{
-		  double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (ret);
 	      return ret;
 	    }
 	  return x + efx * x;
diff --git a/sysdeps/ieee754/dbl-64/s_expm1.c b/sysdeps/ieee754/dbl-64/s_expm1.c
index 41ef63a786..54d771007a 100644
--- a/sysdeps/ieee754/dbl-64/s_expm1.c
+++ b/sysdeps/ieee754/dbl-64/s_expm1.c
@@ -195,11 +195,7 @@ __expm1 (double x)
     }
   else if (hx < 0x3c900000)             /* when |x|<2**-54, return x */
     {
-      if (fabs (x) < DBL_MIN)
-	{
-	  double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       t = huge + x;     /* return x with inexact flags when x!=0 */
       return x - (t - (huge + x));
     }
diff --git a/sysdeps/ieee754/dbl-64/s_fma.c b/sysdeps/ieee754/dbl-64/s_fma.c
index 278b690f9b..8b4e1331f6 100644
--- a/sysdeps/ieee754/dbl-64/s_fma.c
+++ b/sysdeps/ieee754/dbl-64/s_fma.c
@@ -90,8 +90,8 @@ __fma (double x, double y, double z)
 		     && w.ieee.mantissa1 == 0
 		     && w.ieee.mantissa0 == 0)))
 	    {
-	      volatile double force_underflow = x * y;
-	      (void) force_underflow;
+	      double force_underflow = x * y;
+	      math_force_eval (force_underflow);
 	    }
 	  return v.d * 0x1p-54;
 	}
diff --git a/sysdeps/ieee754/dbl-64/s_log1p.c b/sysdeps/ieee754/dbl-64/s_log1p.c
index cff555b0aa..340f6377f7 100644
--- a/sysdeps/ieee754/dbl-64/s_log1p.c
+++ b/sysdeps/ieee754/dbl-64/s_log1p.c
@@ -120,11 +120,7 @@ __log1p (double x)
 	  math_force_eval (two54 + x);          /* raise inexact */
 	  if (ax < 0x3c900000)                  /* |x| < 2**-54 */
 	    {
-	      if (fabs (x) < DBL_MIN)
-		{
-		  double force_underflow = x * x;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (x);
 	      return x;
 	    }
 	  else
diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c
index eff120e88d..48c924c6b6 100644
--- a/sysdeps/ieee754/dbl-64/s_sin.c
+++ b/sysdeps/ieee754/dbl-64/s_sin.c
@@ -297,11 +297,7 @@ __sin (double x)
   k = 0x7fffffff & m;		/* no sign           */
   if (k < 0x3e500000)		/* if x->0 =>sin(x)=x */
     {
-      if (fabs (x) < DBL_MIN)
-	{
-	  double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       retval = x;
     }
  /*---------------------------- 2^-26 < |x|< 0.25 ----------------------*/
diff --git a/sysdeps/ieee754/dbl-64/s_tan.c b/sysdeps/ieee754/dbl-64/s_tan.c
index b4e3bd2a31..65d056adec 100644
--- a/sysdeps/ieee754/dbl-64/s_tan.c
+++ b/sysdeps/ieee754/dbl-64/s_tan.c
@@ -92,11 +92,7 @@ tan (double x)
   /* (I) The case abs(x) <= 1.259e-8 */
   if (w <= g1.d)
     {
-      if (w < DBL_MIN)
-	{
-	  double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow_nonneg (w);
       retval = x;
       goto ret;
     }
diff --git a/sysdeps/ieee754/dbl-64/s_tanh.c b/sysdeps/ieee754/dbl-64/s_tanh.c
index 4f9fcfd2bd..344a2f0330 100644
--- a/sysdeps/ieee754/dbl-64/s_tanh.c
+++ b/sysdeps/ieee754/dbl-64/s_tanh.c
@@ -70,11 +70,7 @@ __tanh (double x)
 	return x;                       /* x == +-0 */
       if (ix < 0x3c800000)              /* |x|<2**-55 */
 	{
-	  if (fabs (x) < DBL_MIN)
-	    {
-	      double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  return x * (one + x);           /* tanh(small) = small */
 	}
       if (ix >= 0x3ff00000)             /* |x|>=1  */
diff --git a/sysdeps/ieee754/flt-32/e_asinf.c b/sysdeps/ieee754/flt-32/e_asinf.c
index 00bad4239b..2ca2dbcb28 100644
--- a/sysdeps/ieee754/flt-32/e_asinf.c
+++ b/sysdeps/ieee754/flt-32/e_asinf.c
@@ -73,11 +73,7 @@ float __ieee754_asinf(float x)
 	    return (x-x)/(x-x);		/* asin(|x|>1) is NaN */
 	} else if (ix<0x3f000000) {	/* |x|<0.5 */
 	    if(ix<0x32000000) {		/* if |x| < 2**-27 */
-		if (fabsf (x) < FLT_MIN)
-		  {
-		    float force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		if(huge+x>one) return x;/* return x with inexact if x!=0*/
 	    } else {
 		t = x*x;
diff --git a/sysdeps/ieee754/flt-32/e_atanhf.c b/sysdeps/ieee754/flt-32/e_atanhf.c
index bc74960e16..77e4b03c75 100644
--- a/sysdeps/ieee754/flt-32/e_atanhf.c
+++ b/sysdeps/ieee754/flt-32/e_atanhf.c
@@ -52,11 +52,7 @@ __ieee754_atanhf (float x)
       if (__glibc_unlikely (xa < 0x1.0p-28f))
 	{
 	  math_force_eval (huge + x);
-	  if (fabsf (x) < FLT_MIN)
-	    {
-	      float force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  return x;
 	}
 
diff --git a/sysdeps/ieee754/flt-32/e_exp2f.c b/sysdeps/ieee754/flt-32/e_exp2f.c
index 170c565895..d8e7a9c8bc 100644
--- a/sysdeps/ieee754/flt-32/e_exp2f.c
+++ b/sysdeps/ieee754/flt-32/e_exp2f.c
@@ -111,11 +111,7 @@ __ieee754_exp2f (float x)
       else
 	{
 	  result *= scale_u.f;
-	  if (result < FLT_MIN)
-	    {
-	      float force_underflow = result * result;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow_nonneg (result);
 	  return result;
 	}
     }
diff --git a/sysdeps/ieee754/flt-32/e_gammaf_r.c b/sysdeps/ieee754/flt-32/e_gammaf_r.c
index 183db1e033..f97ca34705 100644
--- a/sysdeps/ieee754/flt-32/e_gammaf_r.c
+++ b/sysdeps/ieee754/flt-32/e_gammaf_r.c
@@ -179,11 +179,7 @@ __ieee754_gammaf_r (float x, int *signgamp)
 	      float tret = (float) M_PI / (-x * sinpix
 					   * gammaf_positive (-x, &exp2_adj));
 	      ret = __scalbnf (tret, -exp2_adj);
-	      if (ret < FLT_MIN)
-		{
-		  float force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (ret);
 	    }
 	}
       ret = math_narrow_eval (ret);
diff --git a/sysdeps/ieee754/flt-32/e_j1f.c b/sysdeps/ieee754/flt-32/e_j1f.c
index 63de21f609..e24024f22e 100644
--- a/sysdeps/ieee754/flt-32/e_j1f.c
+++ b/sysdeps/ieee754/flt-32/e_j1f.c
@@ -72,10 +72,7 @@ __ieee754_j1f(float x)
 	if(__builtin_expect(ix<0x32000000, 0)) {	/* |x|<2**-27 */
 	    if(huge+x>one) {		/* inexact if x!=0 necessary */
 		float ret = (float) 0.5 * x;
-		if (fabsf (ret) < FLT_MIN) {
-		    float force_underflow = ret * ret;
-		    math_force_eval (force_underflow);
-		}
+		math_check_force_underflow (ret);
 		return ret;
 	    }
 	}
diff --git a/sysdeps/ieee754/flt-32/e_jnf.c b/sysdeps/ieee754/flt-32/e_jnf.c
index 44a3761adb..d18922aa05 100644
--- a/sysdeps/ieee754/flt-32/e_jnf.c
+++ b/sysdeps/ieee754/flt-32/e_jnf.c
@@ -170,10 +170,8 @@ __ieee754_jnf(int n, float x)
     }
     if (ret == 0)
 	ret = __copysignf (FLT_MIN, ret) * FLT_MIN;
-    else if (fabsf (ret) < FLT_MIN) {
-	float force_underflow = ret * ret;
-	math_force_eval (force_underflow);
-    }
+    else
+	math_check_force_underflow (ret);
     return ret;
 }
 strong_alias (__ieee754_jnf, __jnf_finite)
diff --git a/sysdeps/ieee754/flt-32/e_sinhf.c b/sysdeps/ieee754/flt-32/e_sinhf.c
index a24fa0c4bc..6100d95c55 100644
--- a/sysdeps/ieee754/flt-32/e_sinhf.c
+++ b/sysdeps/ieee754/flt-32/e_sinhf.c
@@ -36,11 +36,7 @@ __ieee754_sinhf(float x)
     /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */
 	if (ix < 0x41b00000) {		/* |x|<22 */
 	    if (__builtin_expect(ix<0x31800000, 0)) {	/* |x|<2**-28 */
-		if (fabsf (x) < FLT_MIN)
-		  {
-		    float force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
 	    }
 	    t = __expm1f(fabsf(x));
diff --git a/sysdeps/ieee754/flt-32/k_sinf.c b/sysdeps/ieee754/flt-32/k_sinf.c
index 0c98a2ae91..a195d59466 100644
--- a/sysdeps/ieee754/flt-32/k_sinf.c
+++ b/sysdeps/ieee754/flt-32/k_sinf.c
@@ -38,11 +38,7 @@ float __kernel_sinf(float x, float y, int iy)
 	ix &= 0x7fffffff;			/* high word of x */
 	if(ix<0x32000000)			/* |x| < 2**-27 */
 	  {
-	    if (fabsf (x) < FLT_MIN)
-	      {
-		float force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    if ((int) x == 0)
 	      return x;		/* generate inexact */
 	  }
diff --git a/sysdeps/ieee754/flt-32/k_tanf.c b/sysdeps/ieee754/flt-32/k_tanf.c
index 2f2076d6fe..9f0e55860f 100644
--- a/sysdeps/ieee754/flt-32/k_tanf.c
+++ b/sysdeps/ieee754/flt-32/k_tanf.c
@@ -51,11 +51,7 @@ float __kernel_tanf(float x, float y, int iy)
 		if((ix|(iy+1))==0) return one/fabsf(x);
 		else if (iy == 1)
 		  {
-		    if (fabsf (x) < FLT_MIN)
-		      {
-			float force_underflow = x * x;
-			math_force_eval (force_underflow);
-		      }
+		    math_check_force_underflow (x);
 		    return x;
 		  }
 		else
diff --git a/sysdeps/ieee754/flt-32/s_asinhf.c b/sysdeps/ieee754/flt-32/s_asinhf.c
index 697faa843c..da9cafb600 100644
--- a/sysdeps/ieee754/flt-32/s_asinhf.c
+++ b/sysdeps/ieee754/flt-32/s_asinhf.c
@@ -30,11 +30,7 @@ __asinhf(float x)
 	GET_FLOAT_WORD(hx,x);
 	ix = hx&0x7fffffff;
 	if(__builtin_expect(ix< 0x38000000, 0)) {	/* |x|<2**-14 */
-	    if (fabsf (x) < FLT_MIN)
-	      {
-		float force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    if(huge+x>one) return x;	/* return x inexact except 0 */
 	}
 	if(__builtin_expect(ix>0x47000000, 0)) {	/* |x| > 2**14 */
diff --git a/sysdeps/ieee754/flt-32/s_atanf.c b/sysdeps/ieee754/flt-32/s_atanf.c
index be2addbdff..e322a1d41f 100644
--- a/sysdeps/ieee754/flt-32/s_atanf.c
+++ b/sysdeps/ieee754/flt-32/s_atanf.c
@@ -67,11 +67,7 @@ float __atanf(float x)
 	    else     return -atanhi[3]-atanlo[3];
 	} if (ix < 0x3ee00000) {	/* |x| < 0.4375 */
 	    if (ix < 0x31000000) {	/* |x| < 2^-29 */
-		if (fabsf (x) < FLT_MIN)
-		  {
-		    float force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		if(huge+x>one) return x;	/* raise inexact */
 	    }
 	    id = -1;
diff --git a/sysdeps/ieee754/flt-32/s_erff.c b/sysdeps/ieee754/flt-32/s_erff.c
index 1aabce5cb8..3162d81d08 100644
--- a/sysdeps/ieee754/flt-32/s_erff.c
+++ b/sysdeps/ieee754/flt-32/s_erff.c
@@ -113,11 +113,7 @@ float __erff(float x)
 		  {
 		    /* Avoid spurious underflow.  */
 		    float ret = 0.0625f * (16.0f * x + (16.0f * efx) * x);
-		    if (fabsf (ret) < FLT_MIN)
-		      {
-			float force_underflow = ret * ret;
-			math_force_eval (force_underflow);
-		      }
+		    math_check_force_underflow (ret);
 		    return ret;
 		  }
 		return x + efx*x;
diff --git a/sysdeps/ieee754/flt-32/s_expm1f.c b/sysdeps/ieee754/flt-32/s_expm1f.c
index c81b057f24..c515d25e28 100644
--- a/sysdeps/ieee754/flt-32/s_expm1f.c
+++ b/sysdeps/ieee754/flt-32/s_expm1f.c
@@ -81,11 +81,7 @@ __expm1f(float x)
 	    c  = (hi-x)-lo;
 	}
 	else if(hx < 0x33000000) {	/* when |x|<2**-25, return x */
-	    if (fabsf (x) < FLT_MIN)
-	      {
-		float force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    t = huge+x;	/* return x with inexact flags when x!=0 */
 	    return x - (t-(huge+x));
 	}
diff --git a/sysdeps/ieee754/flt-32/s_log1pf.c b/sysdeps/ieee754/flt-32/s_log1pf.c
index 83a09f1414..ade60a2e27 100644
--- a/sysdeps/ieee754/flt-32/s_log1pf.c
+++ b/sysdeps/ieee754/flt-32/s_log1pf.c
@@ -50,11 +50,7 @@ __log1pf(float x)
 		math_force_eval(two25+x);	/* raise inexact */
 		if (ax<0x24800000)		/* |x| < 2**-54 */
 		  {
-		    if (fabsf (x) < FLT_MIN)
-		      {
-			float force_underflow = x * x;
-			math_force_eval (force_underflow);
-		      }
+		    math_check_force_underflow (x);
 		    return x;
 		  }
 		else
diff --git a/sysdeps/ieee754/flt-32/s_tanhf.c b/sysdeps/ieee754/flt-32/s_tanhf.c
index 5b48fb2e00..f70702b29c 100644
--- a/sysdeps/ieee754/flt-32/s_tanhf.c
+++ b/sysdeps/ieee754/flt-32/s_tanhf.c
@@ -43,11 +43,7 @@ float __tanhf(float x)
 		return x;		/* x == +-0 */
 	    if (ix<0x24000000) 		/* |x|<2**-55 */
 	      {
-		if (fabsf (x) < FLT_MIN)
-		  {
-		    float force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		return x*(one+x);    	/* tanh(small) = small */
 	      }
 	    if (ix>=0x3f800000) {	/* |x|>=1  */
diff --git a/sysdeps/ieee754/ldbl-128/e_asinl.c b/sysdeps/ieee754/ldbl-128/e_asinl.c
index 691ac267fb..5a0e473ef0 100644
--- a/sysdeps/ieee754/ldbl-128/e_asinl.c
+++ b/sysdeps/ieee754/ldbl-128/e_asinl.c
@@ -153,11 +153,7 @@ __ieee754_asinl (long double x)
     {
       if (ix < 0x3fc60000) /* |x| < 2**-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  long double force_inexact = huge + x;
 	  math_force_eval (force_inexact);
 	  return x;		/* return x with inexact if x!=0 */
diff --git a/sysdeps/ieee754/ldbl-128/e_atanhl.c b/sysdeps/ieee754/ldbl-128/e_atanhl.c
index a5a7ee0712..7fa53ef436 100644
--- a/sysdeps/ieee754/ldbl-128/e_atanhl.c
+++ b/sysdeps/ieee754/ldbl-128/e_atanhl.c
@@ -60,11 +60,7 @@ __ieee754_atanhl(long double x)
 	  }
 	if(ix<0x3fc60000 && (huge+x)>zero)	/* x < 2^-57 */
 	  {
-	    if (fabsl (x) < LDBL_MIN)
-	      {
-		long double force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    return x;
 	  }
 
diff --git a/sysdeps/ieee754/ldbl-128/e_expl.c b/sysdeps/ieee754/ldbl-128/e_expl.c
index 1cd095cb77..30ec34136f 100644
--- a/sysdeps/ieee754/ldbl-128/e_expl.c
+++ b/sysdeps/ieee754/ldbl-128/e_expl.c
@@ -232,11 +232,7 @@ __ieee754_expl (long double x)
       else
 	{
 	  result *= scale_u.d;
-	  if (result < LDBL_MIN)
-	    {
-	      long double force_underflow = result * result;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow_nonneg (result);
 	  return result;
 	}
     }
diff --git a/sysdeps/ieee754/ldbl-128/e_gammal_r.c b/sysdeps/ieee754/ldbl-128/e_gammal_r.c
index c44f031745..7c11ae40cd 100644
--- a/sysdeps/ieee754/ldbl-128/e_gammal_r.c
+++ b/sysdeps/ieee754/ldbl-128/e_gammal_r.c
@@ -194,11 +194,7 @@ __ieee754_gammal_r (long double x, int *signgamp)
 	      ret = M_PIl / (-x * sinpix
 			     * gammal_positive (-x, &exp2_adj));
 	      ret = __scalbnl (ret, -exp2_adj);
-	      if (ret < LDBL_MIN)
-		{
-		  long double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (ret);
 	    }
 	}
     }
diff --git a/sysdeps/ieee754/ldbl-128/e_j1l.c b/sysdeps/ieee754/ldbl-128/e_j1l.c
index 591c38efd0..70ecf5eae3 100644
--- a/sysdeps/ieee754/ldbl-128/e_j1l.c
+++ b/sysdeps/ieee754/ldbl-128/e_j1l.c
@@ -700,11 +700,7 @@ __ieee754_j1l (long double x)
   if (xx <= 0x1p-58L)
     {
       long double ret = x * 0.5L;
-      if (fabsl (ret) < LDBL_MIN)
-	{
-	  long double force_underflow = ret * ret;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (ret);
       return ret;
     }
   if (xx <= 2.0L)
diff --git a/sysdeps/ieee754/ldbl-128/e_jnl.c b/sysdeps/ieee754/ldbl-128/e_jnl.c
index a419994a86..ee5a16b62e 100644
--- a/sysdeps/ieee754/ldbl-128/e_jnl.c
+++ b/sysdeps/ieee754/ldbl-128/e_jnl.c
@@ -297,11 +297,8 @@ __ieee754_jnl (int n, long double x)
   }
   if (ret == 0)
     ret = __copysignl (LDBL_MIN, ret) * LDBL_MIN;
-  else if (fabsl (ret) < LDBL_MIN)
-    {
-      long double force_underflow = ret * ret;
-      math_force_eval (force_underflow);
-    }
+  else
+    math_check_force_underflow (ret);
   return ret;
 }
 strong_alias (__ieee754_jnl, __jnl_finite)
diff --git a/sysdeps/ieee754/ldbl-128/e_sinhl.c b/sysdeps/ieee754/ldbl-128/e_sinhl.c
index b0244a828d..11974a39af 100644
--- a/sysdeps/ieee754/ldbl-128/e_sinhl.c
+++ b/sysdeps/ieee754/ldbl-128/e_sinhl.c
@@ -88,11 +88,7 @@ __ieee754_sinhl (long double x)
     {
       if (ix < 0x3fc60000) /* |x| < 2^-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (shuge + x > one)
 	    return x;		/* sinh(tiny) = tiny with inexact */
 	}
diff --git a/sysdeps/ieee754/ldbl-128/k_sincosl.c b/sysdeps/ieee754/ldbl-128/k_sincosl.c
index 7b5c4b0e81..4f0de3d873 100644
--- a/sysdeps/ieee754/ldbl-128/k_sincosl.c
+++ b/sysdeps/ieee754/ldbl-128/k_sincosl.c
@@ -111,11 +111,7 @@ __kernel_sincosl(long double x, long double y, long double *sinx, long double *c
 	 polynomial of degree 16(17).  */
       if (tix < 0x3fc60000)		/* |x| < 2^-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (!((int)x))			/* generate inexact */
 	    {
 	      *sinx = x;
diff --git a/sysdeps/ieee754/ldbl-128/k_sinl.c b/sysdeps/ieee754/ldbl-128/k_sinl.c
index 04d539ff1a..d9ef62c653 100644
--- a/sysdeps/ieee754/ldbl-128/k_sinl.c
+++ b/sysdeps/ieee754/ldbl-128/k_sinl.c
@@ -92,11 +92,7 @@ __kernel_sinl(long double x, long double y, int iy)
 	 polynomial of degree 17.  */
       if (tix < 0x3fc60000)		/* |x| < 2^-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (!((int)x)) return x;	/* generate inexact */
 	}
       z = x * x;
diff --git a/sysdeps/ieee754/ldbl-128/k_tanl.c b/sysdeps/ieee754/ldbl-128/k_tanl.c
index 6a6fa9f0a6..8ff9192947 100644
--- a/sysdeps/ieee754/ldbl-128/k_tanl.c
+++ b/sysdeps/ieee754/ldbl-128/k_tanl.c
@@ -101,11 +101,7 @@ __kernel_tanl (long double x, long double y, int iy)
 	    return one / fabs (x);
 	  else if (iy == 1)
 	    {
-	      if (fabsl (x) < LDBL_MIN)
-		{
-		  long double force_underflow = x * x;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (x);
 	      return x;
 	    }
 	  else
diff --git a/sysdeps/ieee754/ldbl-128/s_asinhl.c b/sysdeps/ieee754/ldbl-128/s_asinhl.c
index 8d5721a73c..5f3b9f2c76 100644
--- a/sysdeps/ieee754/ldbl-128/s_asinhl.c
+++ b/sysdeps/ieee754/ldbl-128/s_asinhl.c
@@ -52,11 +52,7 @@ __asinhl (long double x)
     return x + x;		/* x is inf or NaN */
   if (ix < 0x3fc70000)
     {				/* |x| < 2^ -56 */
-      if (fabsl (x) < LDBL_MIN)
-	{
-	  long double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       if (huge + x > one)
 	return x;		/* return x inexact except 0 */
     }
diff --git a/sysdeps/ieee754/ldbl-128/s_atanl.c b/sysdeps/ieee754/ldbl-128/s_atanl.c
index 1367b6b15d..aaae701551 100644
--- a/sysdeps/ieee754/ldbl-128/s_atanl.c
+++ b/sysdeps/ieee754/ldbl-128/s_atanl.c
@@ -202,11 +202,7 @@ __atanl (long double x)
 
   if (k <= 0x3fc50000) /* |x| < 2**-58 */
     {
-      if (fabsl (x) < LDBL_MIN)
-	{
-	  long double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       /* Raise inexact. */
       if (huge + x > 0.0)
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128/s_erfl.c b/sysdeps/ieee754/ldbl-128/s_erfl.c
index 08c80a33ea..dd275a7dd9 100644
--- a/sysdeps/ieee754/ldbl-128/s_erfl.c
+++ b/sysdeps/ieee754/ldbl-128/s_erfl.c
@@ -785,11 +785,7 @@ __erfl (long double x)
 	    {
 	      /* Avoid spurious underflow.  */
 	      long double ret =  0.0625 * (16.0 * x + (16.0 * efx) * x);
-	      if (fabsl (ret) < LDBL_MIN)
-		{
-		  long double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (ret);
 	      return ret;
 	    }
 	  return x + efx * x;
diff --git a/sysdeps/ieee754/ldbl-128/s_expm1l.c b/sysdeps/ieee754/ldbl-128/s_expm1l.c
index f1a68c878b..b1100a9d0e 100644
--- a/sysdeps/ieee754/ldbl-128/s_expm1l.c
+++ b/sysdeps/ieee754/ldbl-128/s_expm1l.c
@@ -128,11 +128,7 @@ __expm1l (long double x)
      when the result does underflow.  */
   if (fabsl (x) < 0x1p-113L)
     {
-      if (fabsl (x) < LDBL_MIN)
-	{
-	  long double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       return x;
     }
 
diff --git a/sysdeps/ieee754/ldbl-128/s_fmal.c b/sysdeps/ieee754/ldbl-128/s_fmal.c
index 5abc9105e5..e231ce6344 100644
--- a/sysdeps/ieee754/ldbl-128/s_fmal.c
+++ b/sysdeps/ieee754/ldbl-128/s_fmal.c
@@ -94,8 +94,8 @@ __fmal (long double x, long double y, long double z)
 		     && w.ieee.mantissa1 == 0
 		     && w.ieee.mantissa0 == 0)))
 	    {
-	      volatile long double force_underflow = x * y;
-	      (void) force_underflow;
+	      long double force_underflow = x * y;
+	      math_force_eval (force_underflow);
 	    }
 	  return v.d * 0x1p-114L;
 	}
diff --git a/sysdeps/ieee754/ldbl-128/s_log1pl.c b/sysdeps/ieee754/ldbl-128/s_log1pl.c
index 960955077b..9806ab6d63 100644
--- a/sysdeps/ieee754/ldbl-128/s_log1pl.c
+++ b/sysdeps/ieee754/ldbl-128/s_log1pl.c
@@ -140,11 +140,7 @@ __log1pl (long double xm1)
 
   if ((hx & 0x7fffffff) < 0x3f8e0000)
     {
-      if (fabsl (xm1) < LDBL_MIN)
-	{
-	  long double force_underflow = xm1 * xm1;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (xm1);
       if ((int) xm1 == 0)
 	return xm1;
     }
diff --git a/sysdeps/ieee754/ldbl-128/s_tanhl.c b/sysdeps/ieee754/ldbl-128/s_tanhl.c
index 8b1706fcdc..f7a1d20f79 100644
--- a/sysdeps/ieee754/ldbl-128/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-128/s_tanhl.c
@@ -75,11 +75,7 @@ __tanhl (long double x)
 	return x;		/* x == +- 0 */
       if (ix < 0x3fc60000)	/* |x| < 2^-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  return x * (one + tiny); /* tanh(small) = small */
 	}
       u.parts32.w0 = ix;	/* Absolute value of x.  */
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_asinl.c b/sysdeps/ieee754/ldbl-128ibm/e_asinl.c
index 57c3ac09c8..6ed5e8d68d 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_asinl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_asinl.c
@@ -147,11 +147,7 @@ __ieee754_asinl (long double x)
     {
       if (a < 6.938893903907228e-18L) /* |x| < 2**-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  long double force_inexact =  huge + x;
 	  math_force_eval (force_inexact);
 	  return x;		/* return x with inexact if x!=0 */
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c b/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c
index bcd1fce4ed..b576f42030 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c
@@ -57,11 +57,7 @@ __ieee754_atanhl(long double x)
 	}
 	if(ix<0x3c70000000000000LL&&(huge+x)>zero)	/* x<2**-56 */
 	  {
-	    if (fabsl (x) < LDBL_MIN)
-	      {
-		long double force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    return x;
 	  }
 	x = fabsl (x);
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c b/sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c
index 420842e2d6..e8e443ff31 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c
@@ -194,11 +194,7 @@ __ieee754_gammal_r (long double x, int *signgamp)
 	      ret = M_PIl / (-x * sinpix
 			     * gammal_positive (-x, &exp2_adj));
 	      ret = __scalbnl (ret, -exp2_adj);
-	      if (ret < LDBL_MIN)
-		{
-		  long double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (ret);
 	    }
 	}
     }
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
index 7594196a1f..c33bc19d09 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
@@ -297,11 +297,8 @@ __ieee754_jnl (int n, long double x)
   }
   if (ret == 0)
     ret = __copysignl (LDBL_MIN, ret) * LDBL_MIN;
-  else if (fabsl (ret) < LDBL_MIN)
-    {
-      long double force_underflow = ret * ret;
-      math_force_eval (force_underflow);
-    }
+  else
+    math_check_force_underflow (ret);
   return ret;
 }
 strong_alias (__ieee754_jnl, __jnl_finite)
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c b/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c
index 00115df944..29700ad4ab 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_sinhl.c
@@ -54,11 +54,7 @@ __ieee754_sinhl(long double x)
     /* |x| in [0,40], return sign(x)*0.5*(E+E/(E+1))) */
 	if (ix < 0x4044000000000000LL) {	/* |x|<40 */
 	    if (ix<0x3c90000000000000LL) {	/* |x|<2**-54 */
-		if (fabsl (x) < LDBL_MIN)
-		  {
-		    long double force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		if(shuge+x>one) return x;/* sinhl(tiny) = tiny with inexact */
 	    }
 	    t = __expm1l(fabsl(x));
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
index 0a76e1c7e7..b361043dd2 100644
--- a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
@@ -114,11 +114,7 @@ __kernel_sincosl(long double x, long double y, long double *sinx, long double *c
 	 polynomial of degree 16(17).  */
       if (tix < 0x3c600000)		/* |x| < 2^-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (!((int)x))			/* generate inexact */
 	    {
 	      *sinx = x;
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
index 2050cd2b49..800bd547fd 100644
--- a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
@@ -95,11 +95,7 @@ __kernel_sinl(long double x, long double y, int iy)
 	 polynomial of degree 17.  */
       if (tix < 0x3c600000)		/* |x| < 2^-57 */
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (!((int)x)) return x;	/* generate inexact */
 	}
       z = x * x;
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_tanl.c b/sysdeps/ieee754/ldbl-128ibm/k_tanl.c
index e50cc88da4..22e53fcc69 100644
--- a/sysdeps/ieee754/ldbl-128ibm/k_tanl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_tanl.c
@@ -101,11 +101,7 @@ __kernel_tanl (long double x, long double y, int iy)
 	    return one / fabs (x);
 	  else if (iy == 1)
 	    {
-	      if (fabsl (x) < LDBL_MIN)
-		{
-		  long double force_underflow = x * x;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (x);
 	      return x;
 	    }
 	  else
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c b/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c
index dda7f780fc..aa9a9ba213 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_asinhl.c
@@ -46,11 +46,7 @@ long double __asinhl(long double x)
 	ix = hx&0x7fffffffffffffffLL;
 	if(ix>=0x7ff0000000000000LL) return x+x;	/* x is inf or NaN */
 	if(ix< 0x3c70000000000000LL) {	/* |x|<2**-56 */
-	    if (fabsl (x) < LDBL_MIN)
-	      {
-		long double force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    if(huge+x>one) return x;	/* return x inexact except 0 */
 	}
 	if(ix>0x4370000000000000LL) {	/* |x| > 2**56 */
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_atanl.c b/sysdeps/ieee754/ldbl-128ibm/s_atanl.c
index 6ddf4b1c5e..0560d820ae 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_atanl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_atanl.c
@@ -199,11 +199,7 @@ __atanl (long double x)
 
   if (k <= 0x3c800000) /* |x| <= 2**-55.  */
     {
-      if (fabsl (x) < LDBL_MIN)
-	{
-	  long double force_underflow = x * x;
-	  math_force_eval (force_underflow);
-	}
+      math_check_force_underflow (x);
       /* Raise inexact.  */
       if (1e300L + x > 0.0)
 	return x;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_erfl.c b/sysdeps/ieee754/ldbl-128ibm/s_erfl.c
index f6fcf48cfa..455c645561 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_erfl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_erfl.c
@@ -805,11 +805,7 @@ __erfl (long double x)
 	      if (x == 0)
 		return x;
 	      long double ret = 0.0625 * (16.0 * x + (16.0 * efx) * x);
-	      if (fabsl (ret) < LDBL_MIN)
-		{
-		  long double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (ret);
 	      return ret;
 	    }
 	  return x + efx * x;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c b/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c
index 5342a8b19a..292020cabf 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_tanhl.c
@@ -68,11 +68,7 @@ long double __tanhl(long double x)
 		return x;		/* x == +-0 */
 	    if (ix<0x3c60000000000000LL) 	/* |x|<2**-57 */
 	      {
-		if (fabsl (x) < LDBL_MIN)
-		  {
-		    long double force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		return x*(one+x);    	/* tanh(small) = small */
 	      }
 	    if (ix>=0x3ff0000000000000LL) {	/* |x|>=1  */
diff --git a/sysdeps/ieee754/ldbl-96/e_asinl.c b/sysdeps/ieee754/ldbl-96/e_asinl.c
index 2973bf071b..f52b931459 100644
--- a/sysdeps/ieee754/ldbl-96/e_asinl.c
+++ b/sysdeps/ieee754/ldbl-96/e_asinl.c
@@ -112,11 +112,7 @@ __ieee754_asinl (long double x)
     {				/* |x|<0.5 */
       if (ix < 0x3fde8000)
 	{			/* if |x| < 2**-33 */
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (huge + x > one)
 	    return x;		/* return x with inexact if x!=0 */
 	}
diff --git a/sysdeps/ieee754/ldbl-96/e_atanhl.c b/sysdeps/ieee754/ldbl-96/e_atanhl.c
index 9a957c9065..b99a83c6ee 100644
--- a/sysdeps/ieee754/ldbl-96/e_atanhl.c
+++ b/sysdeps/ieee754/ldbl-96/e_atanhl.c
@@ -55,11 +55,7 @@ __ieee754_atanhl(long double x)
 	    return x/zero;
 	if(ix<0x3fdf) {
 	    math_force_eval(huge+x);
-	    if (fabsl (x) < LDBL_MIN)
-	      {
-		long double force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    return x;	/* x<2**-32 */
 	}
 	SET_LDOUBLE_EXP(x,ix);
diff --git a/sysdeps/ieee754/ldbl-96/e_gammal_r.c b/sysdeps/ieee754/ldbl-96/e_gammal_r.c
index a5767e7795..78495d1908 100644
--- a/sysdeps/ieee754/ldbl-96/e_gammal_r.c
+++ b/sysdeps/ieee754/ldbl-96/e_gammal_r.c
@@ -186,11 +186,7 @@ __ieee754_gammal_r (long double x, int *signgamp)
 	      ret = M_PIl / (-x * sinpix
 			     * gammal_positive (-x, &exp2_adj));
 	      ret = __scalbnl (ret, -exp2_adj);
-	      if (ret < LDBL_MIN)
-		{
-		  long double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (ret);
 	    }
 	}
     }
diff --git a/sysdeps/ieee754/ldbl-96/e_j1l.c b/sysdeps/ieee754/ldbl-96/e_j1l.c
index 46e28dfe11..1bca949e5a 100644
--- a/sysdeps/ieee754/ldbl-96/e_j1l.c
+++ b/sysdeps/ieee754/ldbl-96/e_j1l.c
@@ -154,11 +154,7 @@ __ieee754_j1l (long double x)
       if (huge + x > one)		/* inexact if x!=0 necessary */
 	{
 	  long double ret = 0.5 * x;
-	  if (fabsl (ret) < LDBL_MIN)
-	    {
-	      long double force_underflow = ret * ret;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (ret);
 	  return ret;
 	}
     }
diff --git a/sysdeps/ieee754/ldbl-96/e_jnl.c b/sysdeps/ieee754/ldbl-96/e_jnl.c
index 2f3a452f55..ed2068b5e2 100644
--- a/sysdeps/ieee754/ldbl-96/e_jnl.c
+++ b/sysdeps/ieee754/ldbl-96/e_jnl.c
@@ -290,11 +290,8 @@ __ieee754_jnl (int n, long double x)
   }
   if (ret == 0)
     ret = __copysignl (LDBL_MIN, ret) * LDBL_MIN;
-  else if (fabsl (ret) < LDBL_MIN)
-    {
-      long double force_underflow = ret * ret;
-      math_force_eval (force_underflow);
-    }
+  else
+    math_check_force_underflow (ret);
   return ret;
 }
 strong_alias (__ieee754_jnl, __jnl_finite)
diff --git a/sysdeps/ieee754/ldbl-96/e_sinhl.c b/sysdeps/ieee754/ldbl-96/e_sinhl.c
index de6dff6843..095b142621 100644
--- a/sysdeps/ieee754/ldbl-96/e_sinhl.c
+++ b/sysdeps/ieee754/ldbl-96/e_sinhl.c
@@ -60,11 +60,7 @@ __ieee754_sinhl(long double x)
     /* |x| in [0,25], return sign(x)*0.5*(E+E/(E+1))) */
 	if (ix < 0x4003 || (ix == 0x4003 && i0 <= 0xc8000000)) { /* |x|<25 */
 	    if (ix<0x3fdf) {		/* |x|<2**-32 */
-		if (fabsl (x) < LDBL_MIN)
-		  {
-		    long double force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
 	    }
 	    t = __expm1l(fabsl(x));
diff --git a/sysdeps/ieee754/ldbl-96/k_sinl.c b/sysdeps/ieee754/ldbl-96/k_sinl.c
index b7b5ae359d..b709740847 100644
--- a/sysdeps/ieee754/ldbl-96/k_sinl.c
+++ b/sysdeps/ieee754/ldbl-96/k_sinl.c
@@ -96,11 +96,7 @@ __kernel_sinl(long double x, long double y, int iy)
 	 polynomial of degree 17.  */
       if (absx < 0x1p-33L)
 	{
-	  if (fabsl (x) < LDBL_MIN)
-	    {
-	      long double force_underflow = x * x;
-	      math_force_eval (force_underflow);
-	    }
+	  math_check_force_underflow (x);
 	  if (!((int)x)) return x;	/* generate inexact */
 	}
       z = x * x;
diff --git a/sysdeps/ieee754/ldbl-96/k_tanl.c b/sysdeps/ieee754/ldbl-96/k_tanl.c
index 6276c06e71..6bee53e04a 100644
--- a/sysdeps/ieee754/ldbl-96/k_tanl.c
+++ b/sysdeps/ieee754/ldbl-96/k_tanl.c
@@ -98,11 +98,7 @@ __kernel_tanl (long double x, long double y, int iy)
 	    return one / fabsl (x);
 	  else if (iy == 1)
 	    {
-	      if (absx < LDBL_MIN)
-		{
-		  long double force_underflow = x * x;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow_nonneg (absx);
 	      return x;
 	    }
 	  else
diff --git a/sysdeps/ieee754/ldbl-96/s_asinhl.c b/sysdeps/ieee754/ldbl-96/s_asinhl.c
index 75e47c71ea..da49ea5988 100644
--- a/sysdeps/ieee754/ldbl-96/s_asinhl.c
+++ b/sysdeps/ieee754/ldbl-96/s_asinhl.c
@@ -45,11 +45,7 @@ long double __asinhl(long double x)
 	GET_LDOUBLE_EXP(hx,x);
 	ix = hx&0x7fff;
 	if(__builtin_expect(ix< 0x3fde, 0)) {	/* |x|<2**-34 */
-	    if (fabsl (x) < LDBL_MIN)
-	      {
-		long double force_underflow = x * x;
-		math_force_eval (force_underflow);
-	      }
+	    math_check_force_underflow (x);
 	    if(huge+x>one) return x;	/* return x inexact except 0 */
 	}
 	if(__builtin_expect(ix>0x4020,0)) {		/* |x| > 2**34 */
diff --git a/sysdeps/ieee754/ldbl-96/s_erfl.c b/sysdeps/ieee754/ldbl-96/s_erfl.c
index c27de812ca..d00adb1000 100644
--- a/sysdeps/ieee754/ldbl-96/s_erfl.c
+++ b/sysdeps/ieee754/ldbl-96/s_erfl.c
@@ -274,11 +274,7 @@ __erfl (long double x)
 	    {
 	      /* Avoid spurious underflow.  */
 	      long double ret = 0.0625 * (16.0 * x + (16.0 * efx) * x);
-	      if (fabsl (ret) < LDBL_MIN)
-		{
-		  long double force_underflow = ret * ret;
-		  math_force_eval (force_underflow);
-		}
+	      math_check_force_underflow (ret);
 	      return ret;
 	    }
 	  return x + efx * x;
diff --git a/sysdeps/ieee754/ldbl-96/s_fmal.c b/sysdeps/ieee754/ldbl-96/s_fmal.c
index 1232c9ebad..d11885e881 100644
--- a/sysdeps/ieee754/ldbl-96/s_fmal.c
+++ b/sysdeps/ieee754/ldbl-96/s_fmal.c
@@ -92,8 +92,8 @@ __fmal (long double x, long double y, long double z)
 		     && w.ieee.mantissa1 == 0
 		     && w.ieee.mantissa0 == 0x80000000)))
 	    {
-	      volatile long double force_underflow = x * y;
-	      (void) force_underflow;
+	      long double force_underflow = x * y;
+	      math_force_eval (force_underflow);
 	    }
 	  return v.d * 0x1p-65L;
 	}
diff --git a/sysdeps/ieee754/ldbl-96/s_tanhl.c b/sysdeps/ieee754/ldbl-96/s_tanhl.c
index 035037c8c7..38edf9f75e 100644
--- a/sysdeps/ieee754/ldbl-96/s_tanhl.c
+++ b/sysdeps/ieee754/ldbl-96/s_tanhl.c
@@ -71,11 +71,7 @@ long double __tanhl(long double x)
 		return x;		/* x == +- 0 */
 	    if (ix<0x3fc8)		/* |x|<2**-55 */
 	      {
-		if (fabsl (x) < LDBL_MIN)
-		  {
-		    long double force_underflow = x * x;
-		    math_force_eval (force_underflow);
-		  }
+		math_check_force_underflow (x);
 		return x*(one+tiny);	/* tanh(small) = small */
 	      }
 	    if (ix>=0x3fff) {	/* |x|>=1  */