Fix estimate_num_insns

[Jan Hubicka <hubicka at ucw dot cz>]

Hi,
gcc.dg/lto/20081201-2 now fails because whopr is now smart enough to figure out that
main() should be optimized for size rather then speed and stupid enoug thinking that
it does not make sense to inline function that just calls builtin_return_address.
This is another incarnation of optimize_size issue that was mostly fixed by Martin,
but it was missed since whopr was broken at that time.

This time I am fixing it by updating estimate_num_insns to special case this builtin
and other similar to be cheap.  Hopefully this will improve inlining decisions in some
practical cases too.

Bootstrapping/regtesting x86_64-linux, will commit as obvious if it passes.
Honza

	* tree-inline.c (eni_inlining_weights): Kill.
	(estimate_num_insns): Special case more builtins.
Index: tree-inline.c
===================================================================
--- tree-inline.c	(revision 158732)
+++ tree-inline.c	(working copy)
@@ -101,10 +101,6 @@ along with GCC; see the file COPYING3.  
      calls?  */
 
 
-/* Weights that estimate_num_insns uses for heuristics in inlining.  */
-
-eni_weights eni_inlining_weights;
-
 /* Weights that estimate_num_insns uses to estimate the size of the
    produced code.  */
 
@@ -3268,22 +3264,93 @@ estimate_num_insns (gimple stmt, eni_wei
 	if (decl && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
 	  switch (DECL_FUNCTION_CODE (decl))
 	    {
+	    /* Builtins that expand to constants.  */
 	    case BUILT_IN_CONSTANT_P:
-	      return 0;
 	    case BUILT_IN_EXPECT:
-	      return 0;
-
-	    /* Prefetch instruction is not expensive.  */
-	    case BUILT_IN_PREFETCH:
-	      cost = weights->target_builtin_call_cost;
-	      break;
-
+	    case BUILT_IN_OBJECT_SIZE:
+	    case BUILT_IN_UNREACHABLE:
+	    /* Simple register moves or loads from stack.  */
+	    case BUILT_IN_RETURN_ADDRESS:
+	    case BUILT_IN_EXTRACT_RETURN_ADDR:
+	    case BUILT_IN_FROB_RETURN_ADDR:
+	    case BUILT_IN_RETURN:
+	    case BUILT_IN_AGGREGATE_INCOMING_ADDRESS:
+	    case BUILT_IN_FRAME_ADDRESS:
+	    case BUILT_IN_VA_END:
+	    case BUILT_IN_STACK_SAVE:
+	    case BUILT_IN_STACK_RESTORE:
 	    /* Exception state returns or moves registers around.  */
 	    case BUILT_IN_EH_FILTER:
 	    case BUILT_IN_EH_POINTER:
 	    case BUILT_IN_EH_COPY_VALUES:
 	      return 0;
 
+	    /* builtins that are not expensive (that is they are most probably
+	       expanded inline into resonably simple code).  */
+	    case BUILT_IN_ABS:
+	    case BUILT_IN_ALLOCA:
+	    case BUILT_IN_BSWAP32:
+	    case BUILT_IN_BSWAP64:
+	    case BUILT_IN_CLZ:
+	    case BUILT_IN_CLZIMAX:
+	    case BUILT_IN_CLZL:
+	    case BUILT_IN_CLZLL:
+	    case BUILT_IN_CTZ:
+	    case BUILT_IN_CTZIMAX:
+	    case BUILT_IN_CTZL:
+	    case BUILT_IN_CTZLL:
+	    case BUILT_IN_FFS:
+	    case BUILT_IN_FFSIMAX:
+	    case BUILT_IN_FFSL:
+	    case BUILT_IN_FFSLL:
+	    case BUILT_IN_IMAXABS:
+	    case BUILT_IN_FINITE:
+	    case BUILT_IN_FINITEF:
+	    case BUILT_IN_FINITEL:
+	    case BUILT_IN_FINITED32:
+	    case BUILT_IN_FINITED64:
+	    case BUILT_IN_FINITED128:
+	    case BUILT_IN_FPCLASSIFY:
+	    case BUILT_IN_ISFINITE:
+	    case BUILT_IN_ISINF_SIGN:
+	    case BUILT_IN_ISINF:
+	    case BUILT_IN_ISINFF:
+	    case BUILT_IN_ISINFL:
+	    case BUILT_IN_ISINFD32:
+	    case BUILT_IN_ISINFD64:
+	    case BUILT_IN_ISINFD128:
+	    case BUILT_IN_ISNAN:
+	    case BUILT_IN_ISNANF:
+	    case BUILT_IN_ISNANL:
+	    case BUILT_IN_ISNAND32:
+	    case BUILT_IN_ISNAND64:
+	    case BUILT_IN_ISNAND128:
+	    case BUILT_IN_ISNORMAL:
+	    case BUILT_IN_ISGREATER:
+	    case BUILT_IN_ISGREATEREQUAL:
+	    case BUILT_IN_ISLESS:
+	    case BUILT_IN_ISLESSEQUAL:
+	    case BUILT_IN_ISLESSGREATER:
+	    case BUILT_IN_ISUNORDERED:
+	    case BUILT_IN_VA_ARG_PACK:
+	    case BUILT_IN_VA_ARG_PACK_LEN:
+	    case BUILT_IN_VA_COPY:
+	    case BUILT_IN_TRAP:
+	    case BUILT_IN_SAVEREGS:
+	    case BUILT_IN_POPCOUNTL:
+	    case BUILT_IN_POPCOUNTLL:
+	    case BUILT_IN_POPCOUNTIMAX:
+	    case BUILT_IN_POPCOUNT:
+	    case BUILT_IN_PARITYL:
+	    case BUILT_IN_PARITYLL:
+	    case BUILT_IN_PARITYIMAX:
+	    case BUILT_IN_PARITY:
+	    case BUILT_IN_LABS:
+	    case BUILT_IN_LLABS:
+	    case BUILT_IN_PREFETCH:
+	      cost = weights->target_builtin_call_cost;
+	      break;
+
 	    default:
 	      break;
 	    }