PR middle-end/20983

	* tree-ssa-ccp.c (optimize_stdarg_builtin): New function.
	(execute_fold_all_builtins): Call it for BUILT_IN_VA_START,
	BUILT_IN_VA_COPY and BUILT_IN_VA_END.

	* target.h (struct ggc_target): Add expand_builtin_va_start
	hook.
	* target-def.h (TARGET_EXPAND_BUILTIN_VA_START): Define.
	(TARGET_INITIALIZER): Add it.
	* builtins.c (expand_builtin_va_start): Use
	targetm.expand_builtin_va_start hook instead of
	EXPAND_BUILTIN_VA_START macro.
	* alpha/alpha.c (alpha_va_start): Made static.
	(override_options): Clear targetm.expand_builtin_va_start if
	TARGET_UNICOSMK.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* alpha/unicosmk.h (EXPAND_BUILTIN_VA_START): Remove.
	* alpha/alpha.h (EXPAND_BUILTIN_VA_START): Remove.
	* alpha/alpha-protos.h (alpha_va_start): Remove prototype.
	* xtensa/xtensa.h (EXPAND_BUILTIN_VA_START): Remove.
	* xtensa/xtensa.c (TARGET_EXPAND_BUILTIN_VA_START): Define.
	(xtensa_va_start): Made static.
	* xtensa/xtensa-protos.h (xtensa_va_start): Remove prototype.
	* pa/pa-protos.h (hppa_va_start): Remove prototype.
	* pa/pa.h (EXPAND_BUILTIN_VA_START): Remove.
	* pa/pa.c (hppa_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* frv/frv.c (frv_expand_builtin_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* frv/frv-protos.h (frv_expand_builtin_va_start): Remove prototype.
	* frv/frv.h (EXPAND_BUILTIN_VA_START): Remove.
	* i386/i386.c (override_options): Clear
	targetm.expand_builtin_va_start if -m32 or 64-bit MS ABI.
	(ix86_va_start): Made static.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* i386/i386.h (EXPAND_BUILTIN_VA_START): Remove.
	* i386/i386-protos.h (ix86_va_start, ix86_va_arg): Remove prototypes.
	* iq2000/iq2000-protos.h (iq2000_va_start): Remove prototype.
	* iq2000/iq2000.h (EXPAND_BUILTIN_VA_START): Remove.
	* iq2000/iq2000.c (iq2000_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* rs6000/rs6000-protos.h (rs6000_va_start): Remove prototype.
	* rs6000/rs6000.c (rs6000_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	(rs6000_override_options): Clear targetm.expand_builtin_va_start if
	DEFAULT_ABI != ABI_V4.
	* rs6000/rs6000.h (EXPAND_BUILTIN_VA_START): Remove.
	* spu/spu.c (spu_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* spu/spu.h (EXPAND_BUILTIN_VA_START): Remove.
	* spu/spu-protos.h spu_va_start): Remove prototype.
	* stormy16/stormy16.h (EXPAND_BUILTIN_VA_START): Remove.
	* stormy16/stormy16-protos.h (xstormy16_expand_builtin_va_start):
	Remove prototype.
	* stormy16/stormy16.c (xstormy16_expand_builtin_va_start): Made
	static.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* s390/s390-protos.h (s390_va_start): Remove prototype.
	* s390/s390.c (s390_va_start): Made static.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* s390/s390.h (EXPAND_BUILTIN_VA_START): Remove.
	* mn10300/mn10300.h (EXPAND_BUILTIN_VA_START): Remove.
	* mn10300/mn10300-protos.h (mn10300_va_start): Remove prototype.
	* mn10300/mn10300.c (mn10300_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* arc/arc.c (arc_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* arc/arc.h (EXPAND_BUILTIN_VA_START): Remove.
	* arc/arc-protos.h (arc_va_start): Remove prototype.
	* mt/mt-protos.h (mt_va_start): Remove prototype.
	* sparc/sparc.c (sparc_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* sparc/sparc-protos.h (sparc_va_start): Remove prototype.
	* sparc/sparc.h (EXPAND_BUILTIN_VA_START): Remove.
	* sh/sh.c (sh_va_start): Made static, add prototype.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.
	* sh/sh-protos.h (sh_va_start): Remove prototype.
	* sh/sh.h (EXPAND_BUILTIN_VA_START): Remove.
	* mips/mips-protos.h (mips_va_start): Remove prototype.
	* mips/mips.h (EXPAND_BUILTIN_VA_START): Remove.
	* mips/mips.c (mips_va_start): Made static.
	(TARGET_EXPAND_BUILTIN_VA_START): Define.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@130650 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 82 insertions, 0 deletions

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 19d82563a81..15f14c4c608 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -2708,6 +2708,78 @@ optimize_stack_restore (basic_block bb, tree call, block_stmt_iterator i)
   return integer_zero_node;
 }
 
+/* If va_list type is a simple pointer and nothing special is needed,
+   optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0),
+   __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple
+   pointer assignment.  */
+
+static tree
+optimize_stdarg_builtin (tree call)
+{
+  tree callee, lhs, rhs;
+  bool va_list_simple_ptr;
+
+  if (TREE_CODE (call) != CALL_EXPR)
+    return NULL_TREE;
+
+  va_list_simple_ptr = POINTER_TYPE_P (va_list_type_node)
+		       && (TREE_TYPE (va_list_type_node) == void_type_node
+			   || TREE_TYPE (va_list_type_node) == char_type_node);
+
+  callee = get_callee_fndecl (call);
+  switch (DECL_FUNCTION_CODE (callee))
+    {
+    case BUILT_IN_VA_START:
+      if (!va_list_simple_ptr
+	  || targetm.expand_builtin_va_start != NULL
+	  || built_in_decls[BUILT_IN_NEXT_ARG] == NULL)
+	return NULL_TREE;
+
+      if (call_expr_nargs (call) != 2)
+	return NULL_TREE;
+
+      lhs = CALL_EXPR_ARG (call, 0);
+      if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+	  || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
+	     != TYPE_MAIN_VARIANT (va_list_type_node))
+	return NULL_TREE;
+
+      lhs = build_fold_indirect_ref (lhs);
+      rhs = build_call_expr (built_in_decls[BUILT_IN_NEXT_ARG],
+			     1, integer_zero_node);
+      rhs = fold_convert (TREE_TYPE (lhs), rhs);
+      return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
+
+    case BUILT_IN_VA_COPY:
+      if (!va_list_simple_ptr)
+	return NULL_TREE;
+
+      if (call_expr_nargs (call) != 2)
+	return NULL_TREE;
+
+      lhs = CALL_EXPR_ARG (call, 0);
+      if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+	  || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs)))
+	     != TYPE_MAIN_VARIANT (va_list_type_node))
+	return NULL_TREE;
+
+      lhs = build_fold_indirect_ref (lhs);
+      rhs = CALL_EXPR_ARG (call, 1);
+      if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs))
+	  != TYPE_MAIN_VARIANT (va_list_type_node))
+	return NULL_TREE;
+
+      rhs = fold_convert (TREE_TYPE (lhs), rhs);
+      return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs);
+
+    case BUILT_IN_VA_END:
+      return integer_zero_node;
+
+    default:
+      gcc_unreachable ();
+    }
+}
+
 /* Convert EXPR into a GIMPLE value suitable for substitution on the
    RHS of an assignment.  Insert the necessary statements before
    iterator *SI_P. 
@@ -2796,6 +2868,16 @@ execute_fold_all_builtins (void)
 		result = optimize_stack_restore (bb, *stmtp, i);
 		if (result)
 		  break;
+		bsi_next (&i);
+		continue;
+
+	      case BUILT_IN_VA_START:
+	      case BUILT_IN_VA_END:
+	      case BUILT_IN_VA_COPY:
+		/* These shouldn't be folded before pass_stdarg.  */
+		result = optimize_stdarg_builtin (*stmtp);
+		if (result)
+		  break;
 		/* FALLTHRU */
 
 	      default: