* builtins.c (expand_builtin_pow, fold_builtin_cabs,

	fold_builtin_sqrt, fold_builtin_cbrt, fold_builtin_logarithm,
	fold_builtin_hypot, fold_builtin_pow): Remove uses of dconst3,
	dconstsqrt2, dconstthird, dconste and/or dconst10.
	* config/i386/i386.c (ix86_emit_swsqrtsf): Likewise.
	* emit-rtl.c (dconst3, dconst10, dconstm2, dconstthird,
	dconstsqrt2, dconste): Delete.
	(init_emit_once): Likewise.  Simplify initializing dconstm1.
	Constify variable.
	* real.c (get_real_const): New.
	* real.h (dconst3, dconst10, dconstm2, dconstthird,
	dconstsqrt2, dconste): Delete.
	(real_value_const, get_real_const): New.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@133607 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 43 insertions, 0 deletions

diff --git a/gcc/real.c b/gcc/real.c
index 38f18a8462a..ac3b7dc02ec 100644
--- a/gcc/real.c
+++ b/gcc/real.c
@@ -2163,6 +2163,49 @@ times_pten (REAL_VALUE_TYPE *r, int exp)
     do_divide (r, r, &pten);
 }
 
+/* Returns the special REAL_VALUE_TYPE enumerated by E.  */
+
+const REAL_VALUE_TYPE *
+get_real_const (enum real_value_const e)
+{
+  static REAL_VALUE_TYPE value[rv_max];
+
+  gcc_assert (e < rv_max);
+
+  /* Initialize mathematical constants for constant folding builtins.
+     These constants need to be given to at least 160 bits precision.  */
+  if (value[e].cl == rvc_zero)
+    switch (e)
+    {
+    case rv_e:
+      {
+	mpfr_t m;
+	mpfr_init2 (m, SIGNIFICAND_BITS);
+	mpfr_set_ui (m, 1, GMP_RNDN);
+	mpfr_exp (m, m, GMP_RNDN);
+	real_from_mpfr (&value[e], m, NULL_TREE, GMP_RNDN);
+	mpfr_clear (m);
+      }
+      break;
+    case rv_third:
+      real_arithmetic (&value[e], RDIV_EXPR, &dconst1, real_digit (3));
+      break;
+    case rv_sqrt2:
+      {
+	mpfr_t m;
+	mpfr_init2 (m, SIGNIFICAND_BITS);
+	mpfr_sqrt_ui (m, 2, GMP_RNDN);
+	real_from_mpfr (&value[e], m, NULL_TREE, GMP_RNDN);
+	mpfr_clear (m);
+      }
+      break;
+    default:
+      gcc_unreachable();
+    }
+
+  return &value[e];
+}
+
 /* Fills R with +Inf.  */
 
 void