[PATCH] Optab: add isfinite_optab for __builtin_isfinite

[HAO CHEN GUI]

Hi,
  This patch adds an optab for __builtin_isfinite. The finite check can be
implemented on rs6000 by a single instruction. It needs an optab to be
expanded to the certain sequence of instructions.

  The subsequent patches will implement the expand on rs6000.

  Bootstrapped and tested on x86 and powerpc64-linux BE and LE with no
regressions. Is this OK for next stage-1?

Thanks
Gui Haochen

ChangeLog
optab: Add isfinite_optab for isfinite builtin

gcc/
        * builtins.cc (interclass_mathfn_icode): Set optab to isfinite_optab
        for isfinite builtin.
        * optabs.def (isfinite_optab): New.

patch.diff
diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index d2786f207b8..5262aa01660 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -2459,8 +2459,9 @@ interclass_mathfn_icode (tree arg, tree fndecl)
       errno_set = true; builtin_optab = ilogb_optab; break;
     CASE_FLT_FN (BUILT_IN_ISINF):
       builtin_optab = isinf_optab; break;
-    case BUILT_IN_ISNORMAL:
     case BUILT_IN_ISFINITE:
+      builtin_optab = isfinite_optab; break;
+    case BUILT_IN_ISNORMAL:
     CASE_FLT_FN (BUILT_IN_FINITE):
     case BUILT_IN_FINITED32:
     case BUILT_IN_FINITED64:
diff --git a/gcc/optabs.def b/gcc/optabs.def
index ad14f9328b9..dcd77315c2a 100644
--- a/gcc/optabs.def
+++ b/gcc/optabs.def
@@ -352,6 +352,7 @@ OPTAB_D (fmod_optab, "fmod$a3")
 OPTAB_D (hypot_optab, "hypot$a3")
 OPTAB_D (ilogb_optab, "ilogb$a2")
 OPTAB_D (isinf_optab, "isinf$a2")
+OPTAB_D (isfinite_optab, "isfinite$a2")
 OPTAB_D (issignaling_optab, "issignaling$a2")
 OPTAB_D (ldexp_optab, "ldexp$a3")
 OPTAB_D (log10_optab, "log10$a2")