[PATCH]: PR middle-end/29335 Restrict MPFR opts to targets where float base is two

["Kaveh R. GHAZI" <ghazi at caip dot rutgers dot edu>]

Based on discussion here:
http://gcc.gnu.org/ml/gcc/2006-12/msg00072.html

I've created the patch below which restricts the use of MPFR to handle
transcendental optimizations to targets where float base equals two.

Tested on sparc-sun-solaris2.10, no regressions.

Okay for mainline?

		Thanks,
		--Kaveh


2006-12-10  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>

	PR middle-end/29335
	* builtins.c (do_mpfr_arg1, do_mpfr_arg2, do_mpfr_arg3,
	do_mpfr_sincos): Ensure target base equals two.

diff -rup orig/egcc-SVN20061209/gcc/builtins.c egcc-SVN20061209/gcc/builtins.c
--- orig/egcc-SVN20061209/gcc/builtins.c	2006-12-07 20:01:47.000000000 -0500
+++ egcc-SVN20061209/gcc/builtins.c	2006-12-10 20:39:50.693205583 -0500
@@ -11557,7 +11557,10 @@ do_mpfr_arg1 (tree arg, tree type, int (

   STRIP_NOPS (arg);

-  if (TREE_CODE (arg) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg))
+  /* To proceed, MPFR must exactly represent the target floating point
+     format, which only happens when the target base equals two.  */
+  if (REAL_MODE_FORMAT (TYPE_MODE (type))->b == 2
+      && TREE_CODE (arg) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg))
     {
       const REAL_VALUE_TYPE *const ra = &TREE_REAL_CST (arg);

@@ -11596,7 +11599,10 @@ do_mpfr_arg2 (tree arg1, tree arg2, tree
   STRIP_NOPS (arg1);
   STRIP_NOPS (arg2);

-  if (TREE_CODE (arg1) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg1)
+  /* To proceed, MPFR must exactly represent the target floating point
+     format, which only happens when the target base equals two.  */
+  if (REAL_MODE_FORMAT (TYPE_MODE (type))->b == 2
+      && TREE_CODE (arg1) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg1)
       && TREE_CODE (arg2) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg2))
     {
       const REAL_VALUE_TYPE *const ra1 = &TREE_REAL_CST (arg1);
@@ -11638,7 +11644,10 @@ do_mpfr_arg3 (tree arg1, tree arg2, tree
   STRIP_NOPS (arg2);
   STRIP_NOPS (arg3);

-  if (TREE_CODE (arg1) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg1)
+  /* To proceed, MPFR must exactly represent the target floating point
+     format, which only happens when the target base equals two.  */
+  if (REAL_MODE_FORMAT (TYPE_MODE (type))->b == 2
+      && TREE_CODE (arg1) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg1)
       && TREE_CODE (arg2) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg2)
       && TREE_CODE (arg3) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg3))
     {
@@ -11676,17 +11685,20 @@ do_mpfr_arg3 (tree arg1, tree arg2, tree
 static tree
 do_mpfr_sincos (tree arg, tree arg_sinp, tree arg_cosp)
 {
+  tree const type = TREE_TYPE (arg);
   tree result = NULL_TREE;

   STRIP_NOPS (arg);

-  if (TREE_CODE (arg) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg))
+  /* To proceed, MPFR must exactly represent the target floating point
+     format, which only happens when the target base equals two.  */
+  if (REAL_MODE_FORMAT (TYPE_MODE (type))->b == 2
+      && TREE_CODE (arg) == REAL_CST && ! TREE_CONSTANT_OVERFLOW (arg))
     {
       const REAL_VALUE_TYPE *const ra = &TREE_REAL_CST (arg);

       if (!real_isnan (ra) && !real_isinf (ra))
         {
-	  tree const type = TREE_TYPE (arg);
 	  const int prec = REAL_MODE_FORMAT (TYPE_MODE (type))->p;
 	  tree result_s, result_c;
 	  int inexact;