Use math_narrow_eval more consistently.

Where glibc code needs to avoid excess range and precision in
floating-point arithmetic, code variously uses either asms or volatile
to force the results of that arithmetic to memory; mostly this is
conditional on FLT_EVAL_METHOD, but in the case of lrint / llrint
functions some use of volatile is unconditional (and is present
unnecessarily in versions for long double).  This patch make such code
use the recently-added math_narrow_eval macro consistently, removing
the unnecessary uses of volatile in long double lrint / llrint
implementations completely.

Tested for x86_64, x86, mips64 and powerpc.

	* math/s_nexttowardf.c (__nexttowardf): Use math_narrow_eval.
	* stdlib/strtod_l.c: Include <math_private.h>.
	(overflow_value): Use math_narrow_eval.
	(underflow_value): Likewise.
	* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
	* sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise.
	* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Likewise.
	(__ieee754_gamma_r): Likewise.
	* sysdeps/ieee754/dbl-64/gamma_productf.c (__gamma_productf):
	Likewise.
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
	Likewise.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c (__lgamma_neg): Likewise.
	* sysdeps/ieee754/dbl-64/s_erf.c (__erfc): Likewise.
	* sysdeps/ieee754/dbl-64/s_llrint.c (__llrint): Likewise.
	* sysdeps/ieee754/dbl-64/s_lrint.c (__lrint): Likewise.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Likewise.
	(__ieee754_gammaf_r): Likewise.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
	Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c (__lgamma_negf): Likewise.
	* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Likewise.
	* sysdeps/ieee754/flt-32/s_llrintf.c (__llrintf): Likewise.
	* sysdeps/ieee754/flt-32/s_lrintf.c (__lrintf): Likewise.
	* sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl): Do not use
	volatile.
	* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl): Likewise.
	* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Use
	math_narrow_eval.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
	Likewise.
	* sysdeps/ieee754/ldbl-96/gamma_product.c (__gamma_product):
	Likewise.
	* sysdeps/ieee754/ldbl-96/s_llrintl.c (__llrintl): Do not use
	volatile.
	* sysdeps/ieee754/ldbl-96/s_lrintl.c (__lrintl): Likewise.
	* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Use
	math_narrow_eval.
	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
	Likewise.
	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
	Likewise.

7 files changed, 24 insertions, 61 deletions

diff --git a/sysdeps/ieee754/dbl-64/e_gamma_r.c b/sysdeps/ieee754/dbl-64/e_gamma_r.c
index d1acaa6a12..d3fb8af97e 100644
--- a/sysdeps/ieee754/dbl-64/e_gamma_r.c
+++ b/sysdeps/ieee754/dbl-64/e_gamma_r.c
@@ -76,11 +76,7 @@ gamma_positive (double x, int *exp2_adj)
 	  /* Adjust into the range for applying Stirling's
 	     approximation.  */
 	  double n = __ceil (12.0 - x);
-#if FLT_EVAL_METHOD != 0
-	  volatile
-#endif
-	  double x_tmp = x + n;
-	  x_adj = x_tmp;
+	  x_adj = math_narrow_eval (x + n);
 	  x_eps = (x - (x_adj - n));
 	  prod = __gamma_product (x_adj - n, x_eps, n, &eps);
 	}
@@ -119,9 +115,6 @@ __ieee754_gamma_r (double x, int *signgamp)
 {
   int32_t hx;
   u_int32_t lx;
-#if FLT_EVAL_METHOD != 0
-  volatile
-#endif
   double ret;
 
   EXTRACT_WORDS (hx, lx, x);
@@ -157,7 +150,7 @@ __ieee754_gamma_r (double x, int *signgamp)
     {
       /* Overflow.  */
       *signgamp = 0;
-      ret = DBL_MAX * DBL_MAX;
+      ret = math_narrow_eval (DBL_MAX * DBL_MAX);
       return ret;
     }
   else
@@ -201,27 +194,28 @@ __ieee754_gamma_r (double x, int *signgamp)
 		}
 	    }
 	}
+      ret = math_narrow_eval (ret);
     }
   if (isinf (ret) && x != 0)
     {
       if (*signgamp < 0)
 	{
-	  ret = -__copysign (DBL_MAX, ret) * DBL_MAX;
+	  ret = math_narrow_eval (-__copysign (DBL_MAX, ret) * DBL_MAX);
 	  ret = -ret;
 	}
       else
-	ret = __copysign (DBL_MAX, ret) * DBL_MAX;
+	ret = math_narrow_eval (__copysign (DBL_MAX, ret) * DBL_MAX);
       return ret;
     }
   else if (ret == 0)
     {
       if (*signgamp < 0)
 	{
-	  ret = -__copysign (DBL_MIN, ret) * DBL_MIN;
+	  ret = math_narrow_eval (-__copysign (DBL_MIN, ret) * DBL_MIN);
 	  ret = -ret;
 	}
       else
-	ret = __copysign (DBL_MIN, ret) * DBL_MIN;
+	ret = math_narrow_eval (__copysign (DBL_MIN, ret) * DBL_MIN);
       return ret;
     }
   else
diff --git a/sysdeps/ieee754/dbl-64/gamma_productf.c b/sysdeps/ieee754/dbl-64/gamma_productf.c
index df59e1beec..2d3c73442b 100644
--- a/sysdeps/ieee754/dbl-64/gamma_productf.c
+++ b/sysdeps/ieee754/dbl-64/gamma_productf.c
@@ -36,10 +36,7 @@ __gamma_productf (float x, float x_eps, int n, float *eps)
   for (int i = 1; i < n; i++)
     ret *= x_full + i;
 
-#if FLT_EVAL_METHOD != 0
-  volatile
-#endif
-  float fret = ret;
+  float fret = math_narrow_eval ((float) ret);
   *eps = (ret - fret) / fret;
 
   return fret;
diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
index 047c6c2886..e58c9e854c 100644
--- a/sysdeps/ieee754/dbl-64/k_rem_pio2.c
+++ b/sysdeps/ieee754/dbl-64/k_rem_pio2.c
@@ -315,34 +315,25 @@ recompute:
       break;
     case 1:
     case 2:;
-#if __FLT_EVAL_METHOD__ != 0
-      volatile
-#endif
       double fv = 0.0;
       for (i = jz; i >= 0; i--)
-	fv += fq[i];
+	fv = math_narrow_eval (fv + fq[i]);
       y[0] = (ih == 0) ? fv : -fv;
-      fv = fq[0] - fv;
+      fv = math_narrow_eval (fq[0] - fv);
       for (i = 1; i <= jz; i++)
-	fv += fq[i];
+	fv = math_narrow_eval (fv + fq[i]);
       y[1] = (ih == 0) ? fv : -fv;
       break;
     case 3:             /* painful */
       for (i = jz; i > 0; i--)
 	{
-#if __FLT_EVAL_METHOD__ != 0
-	  volatile
-#endif
-	  double fv = (double) (fq[i - 1] + fq[i]);
+	  double fv = math_narrow_eval (fq[i - 1] + fq[i]);
 	  fq[i] += fq[i - 1] - fv;
 	  fq[i - 1] = fv;
 	}
       for (i = jz; i > 1; i--)
 	{
-#if __FLT_EVAL_METHOD__ != 0
-	  volatile
-#endif
-	  double fv = (double) (fq[i - 1] + fq[i]);
+	  double fv = math_narrow_eval (fq[i - 1] + fq[i]);
 	  fq[i] += fq[i - 1] - fv;
 	  fq[i - 1] = fv;
 	}
diff --git a/sysdeps/ieee754/dbl-64/lgamma_neg.c b/sysdeps/ieee754/dbl-64/lgamma_neg.c
index 8f54a0f98e..9544600015 100644
--- a/sysdeps/ieee754/dbl-64/lgamma_neg.c
+++ b/sysdeps/ieee754/dbl-64/lgamma_neg.c
@@ -330,17 +330,9 @@ __lgamma_neg (double x, int *signgamp)
     }
 
   double log_gamma_ratio;
-#if FLT_EVAL_METHOD != 0
-  volatile
-#endif
-  double y0_tmp = 1 - x0_hi;
-  double y0 = y0_tmp;
+  double y0 = math_narrow_eval (1 - x0_hi);
   double y0_eps = -x0_hi + (1 - y0) - x0_lo;
-#if FLT_EVAL_METHOD != 0
-  volatile
-#endif
-  double y_tmp = 1 - x;
-  double y = y_tmp;
+  double y = math_narrow_eval (1 - x);
   double y_eps = -x + (1 - y);
   /* We now wish to compute LOG_GAMMA_RATIO
      = log (gamma (Y0 + Y0_EPS) / gamma (Y + Y_EPS)).  XDIFF
@@ -353,19 +345,11 @@ __lgamma_neg (double x, int *signgamp)
     {
       int n_up = (7 - i) / 2;
       double ny0, ny0_eps, ny, ny_eps;
-#if FLT_EVAL_METHOD != 0
-      volatile
-#endif
-      double y0_tmp = y0 + n_up;
-      ny0 = y0_tmp;
+      ny0 = math_narrow_eval (y0 + n_up);
       ny0_eps = y0 - (ny0 - n_up) + y0_eps;
       y0 = ny0;
       y0_eps = ny0_eps;
-#if FLT_EVAL_METHOD != 0
-      volatile
-#endif
-      double y_tmp = y + n_up;
-      ny = y_tmp;
+      ny = math_narrow_eval (y + n_up);
       ny_eps = y - (ny - n_up) + y_eps;
       y = ny;
       y_eps = ny_eps;
diff --git a/sysdeps/ieee754/dbl-64/s_erf.c b/sysdeps/ieee754/dbl-64/s_erf.c
index ea0a73424e..77cd50d935 100644
--- a/sysdeps/ieee754/dbl-64/s_erf.c
+++ b/sysdeps/ieee754/dbl-64/s_erf.c
@@ -402,10 +402,7 @@ __erfc (double x)
 	  __ieee754_exp ((z - x) * (z + x) + R / S);
       if (hx > 0)
 	{
-#if FLT_EVAL_METHOD != 0
-	  volatile
-#endif
-	  double ret = r / x;
+	  double ret = math_narrow_eval (r / x);
 	  if (ret == 0)
 	    __set_errno (ERANGE);
 	  return ret;
diff --git a/sysdeps/ieee754/dbl-64/s_llrint.c b/sysdeps/ieee754/dbl-64/s_llrint.c
index 62acb67c38..048331e9a7 100644
--- a/sysdeps/ieee754/dbl-64/s_llrint.c
+++ b/sysdeps/ieee754/dbl-64/s_llrint.c
@@ -35,7 +35,7 @@ __llrint (double x)
   int32_t j0;
   u_int32_t i1, i0;
   long long int result;
-  volatile double w;
+  double w;
   double t;
   int sx;
 
@@ -47,7 +47,7 @@ __llrint (double x)
 
   if (j0 < 20)
     {
-      w = two52[sx] + x;
+      w = math_narrow_eval (two52[sx] + x);
       t = w - two52[sx];
       EXTRACT_WORDS (i0, i1, t);
       j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
@@ -62,7 +62,7 @@ __llrint (double x)
 	result = (((long long int) i0 << 32) | i1) << (j0 - 52);
       else
 	{
-	  w = two52[sx] + x;
+	  w = math_narrow_eval (two52[sx] + x);
 	  t = w - two52[sx];
 	  EXTRACT_WORDS (i0, i1, t);
 	  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
diff --git a/sysdeps/ieee754/dbl-64/s_lrint.c b/sysdeps/ieee754/dbl-64/s_lrint.c
index 9cce37f3cf..353d5f503b 100644
--- a/sysdeps/ieee754/dbl-64/s_lrint.c
+++ b/sysdeps/ieee754/dbl-64/s_lrint.c
@@ -34,7 +34,7 @@ __lrint (double x)
 {
   int32_t j0;
   u_int32_t i0, i1;
-  volatile double w;
+  double w;
   double t;
   long int result;
   int sx;
@@ -47,7 +47,7 @@ __lrint (double x)
 
   if (j0 < 20)
     {
-      w = two52[sx] + x;
+      w = math_narrow_eval (two52[sx] + x);
       t = w - two52[sx];
       EXTRACT_WORDS (i0, i1, t);
       j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
@@ -62,7 +62,7 @@ __lrint (double x)
 	result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52));
       else
 	{
-	  w = two52[sx] + x;
+	  w = math_narrow_eval (two52[sx] + x);
 	  t = w - two52[sx];
 	  EXTRACT_WORDS (i0, i1, t);
 	  j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;