Create and use SET_RESTORE_ROUND{,_NOEX,_53BIT}{,F,L}.

1 files changed, 44 insertions, 45 deletions

diff --git a/sysdeps/ieee754/flt-32/e_exp2f.c b/sysdeps/ieee754/flt-32/e_exp2f.c
index e728e6ec74..267d81b23f 100644
--- a/sysdeps/ieee754/flt-32/e_exp2f.c
+++ b/sysdeps/ieee754/flt-32/e_exp2f.c
@@ -54,53 +54,52 @@ __ieee754_exp2f (float x)
       int tval, unsafe;
       float rx, x22, result;
       union ieee754_float ex2_u, scale_u;
-      fenv_t oldenv;
-
-      libc_feholdexcept_setroundf (&oldenv, FE_TONEAREST);
-
-      /* 1. Argument reduction.
-	 Choose integers ex, -128 <= t < 128, and some real
-	 -1/512 <= x1 <= 1/512 so that
-	 x = ex + t/512 + x1.
-
-	 First, calculate rx = ex + t/256.  */
-      rx = x + THREEp14;
-      rx -= THREEp14;
-      x -= rx;  /* Compute x=x1. */
-      /* Compute tval = (ex*256 + t)+128.
-	 Now, t = (tval mod 256)-128 and ex=tval/256  [that's mod, NOT %; and
-	 /-round-to-nearest not the usual c integer /].  */
-      tval = (int) (rx * 256.0f + 128.0f);
-
-      /* 2. Adjust for accurate table entry.
-	 Find e so that
-	 x = ex + t/256 + e + x2
-	 where -7e-4 < e < 7e-4, and
-	 (float)(2^(t/256+e))
-	 is accurate to one part in 2^-64.  */
-
-      /* 'tval & 255' is the same as 'tval%256' except that it's always
-	 positive.
-	 Compute x = x2.  */
-      x -= __exp2f_deltatable[tval & 255];
-
-      /* 3. Compute ex2 = 2^(t/255+e+ex).  */
-      ex2_u.f = __exp2f_atable[tval & 255];
-      tval >>= 8;
-      unsafe = abs(tval) >= -FLT_MIN_EXP - 1;
-      ex2_u.ieee.exponent += tval >> unsafe;
-      scale_u.f = 1.0;
-      scale_u.ieee.exponent += tval - (tval >> unsafe);
-
-      /* 4. Approximate 2^x2 - 1, using a second-degree polynomial,
-	 with maximum error in [-2^-9 - 2^-14, 2^-9 + 2^-14]
-	 less than 1.3e-10.  */
-
-      x22 = (.24022656679f * x + .69314736128f) * ex2_u.f;
 
-      /* 5. Return (2^x2-1) * 2^(t/512+e+ex) + 2^(t/512+e+ex).  */
-      libc_fesetenv (&oldenv);
+      {
+	SET_RESTORE_ROUND_NOEXF (FE_TONEAREST);
+
+	/* 1. Argument reduction.
+	   Choose integers ex, -128 <= t < 128, and some real
+	   -1/512 <= x1 <= 1/512 so that
+	   x = ex + t/512 + x1.
+
+	   First, calculate rx = ex + t/256.  */
+	rx = x + THREEp14;
+	rx -= THREEp14;
+	x -= rx;  /* Compute x=x1. */
+	/* Compute tval = (ex*256 + t)+128.
+	   Now, t = (tval mod 256)-128 and ex=tval/256  [that's mod, NOT %;
+	   and /-round-to-nearest not the usual c integer /].  */
+	tval = (int) (rx * 256.0f + 128.0f);
+
+	/* 2. Adjust for accurate table entry.
+	   Find e so that
+	   x = ex + t/256 + e + x2
+	   where -7e-4 < e < 7e-4, and
+	   (float)(2^(t/256+e))
+	   is accurate to one part in 2^-64.  */
+
+	/* 'tval & 255' is the same as 'tval%256' except that it's always
+	   positive.
+	   Compute x = x2.  */
+	x -= __exp2f_deltatable[tval & 255];
+
+	/* 3. Compute ex2 = 2^(t/255+e+ex).  */
+	ex2_u.f = __exp2f_atable[tval & 255];
+	tval >>= 8;
+	unsafe = abs(tval) >= -FLT_MIN_EXP - 1;
+	ex2_u.ieee.exponent += tval >> unsafe;
+	scale_u.f = 1.0;
+	scale_u.ieee.exponent += tval - (tval >> unsafe);
+
+	/* 4. Approximate 2^x2 - 1, using a second-degree polynomial,
+	   with maximum error in [-2^-9 - 2^-14, 2^-9 + 2^-14]
+	   less than 1.3e-10.  */
+
+	x22 = (.24022656679f * x + .69314736128f) * ex2_u.f;
+      }
 
+      /* 5. Return (2^x2-1) * 2^(t/512+e+ex) + 2^(t/512+e+ex).  */
       result = x22 * x + ex2_u.f;
 
       if (!unsafe)