* builtins.c (expand_builtin_strstr): New function.

	(expand_builtin): Handle BUILT_IN_STRSTR and BUILT_IN_STRCHR.

	* builtins.def (BUILT_IN_STRSTR, BUILT_IN_STRCHR): New entries.

	* c-common.c (c_common_nodes_and_builtins): Declare builtin strstr
	and builtin strchr.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@37181 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 68 insertions, 0 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 3304b68a46a..abb67476cd6 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -108,6 +108,8 @@ static rtx expand_builtin_memset	PARAMS ((tree));
 static rtx expand_builtin_bzero		PARAMS ((tree));
 static rtx expand_builtin_strlen	PARAMS ((tree, rtx,
 						 enum machine_mode));
+static rtx expand_builtin_strstr	PARAMS ((tree, rtx,
+						 enum machine_mode));
 static rtx expand_builtin_alloca	PARAMS ((tree, rtx));
 static rtx expand_builtin_ffs		PARAMS ((tree, rtx, rtx));
 static rtx expand_builtin_frame_address	PARAMS ((tree));
@@ -1431,6 +1433,64 @@ expand_builtin_strlen (exp, target, mode)
     }
 }
 
+/* Expand a call to the strstr builtin.  Return 0 if we failed the
+   caller should emit a normal call, otherwise try to get the result
+   in TARGET, if convenient (and in mode MODE if that's convenient).  */
+
+static rtx
+expand_builtin_strstr (arglist, target, mode)
+     tree arglist;
+     rtx target;
+     enum machine_mode mode;
+{
+  if (arglist == 0
+      || TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) != POINTER_TYPE
+      || TREE_CHAIN (arglist) == 0
+      || TREE_CODE (TREE_TYPE (TREE_VALUE (TREE_CHAIN (arglist)))) != POINTER_TYPE)
+    return 0;
+  else
+    {
+      tree s1 = TREE_VALUE (arglist), s2 = TREE_VALUE (TREE_CHAIN (arglist));
+      tree len = c_strlen (s2);
+
+      if (!len)
+	return 0;
+
+      switch (compare_tree_int (len, 1))
+        {
+	case -1: /* length is 0, return s1.  */
+	  return expand_expr (s1, target, mode, EXPAND_NORMAL);
+	case 0: /* length is 1, return strchr(s1, s2[0]).  */
+	  {
+	    tree call_expr, fn = built_in_decls[BUILT_IN_STRCHR];
+
+	    if (!fn)
+	      return 0;
+	    STRIP_NOPS (s2);
+	    if (s2 && TREE_CODE (s2) == ADDR_EXPR)
+	      s2 = TREE_OPERAND (s2, 0);
+
+	    /* New argument list transforming strstr(s1, s2) to
+	       strchr(s1, s2[0]).  */
+	    arglist =
+	      build_tree_list (NULL_TREE,
+			       build_int_2 (TREE_STRING_POINTER (s2)[0], 0));
+	    arglist = tree_cons (NULL_TREE, s1, arglist);
+	    call_expr = build1 (ADDR_EXPR,
+				build_pointer_type (TREE_TYPE (fn)), fn);
+	    call_expr = build (CALL_EXPR, TREE_TYPE (TREE_TYPE (fn)),
+			       call_expr, arglist, NULL_TREE);
+	    TREE_SIDE_EFFECTS (call_expr) = 1;
+	    return expand_expr (call_expr, target, mode, EXPAND_NORMAL);
+	  }
+	case 1: /* length is greater than 1, really call strstr.  */
+	  return 0;
+	default:
+	  abort();
+	}
+    }
+}
+
 /* Expand a call to the memcpy builtin, with arguments in ARGLIST.  */
 static rtx
 expand_builtin_memcpy (arglist)
@@ -2475,6 +2535,7 @@ expand_builtin (exp, target, subtarget, mode, ignore)
 	  || fcode == BUILT_IN_MEMCPY || fcode == BUILT_IN_MEMCMP
 	  || fcode == BUILT_IN_BCMP || fcode == BUILT_IN_BZERO
 	  || fcode == BUILT_IN_STRLEN || fcode == BUILT_IN_STRCPY
+	  || fcode == BUILT_IN_STRSTR
 	  || fcode == BUILT_IN_STRCMP || fcode == BUILT_IN_FFS
 	  || fcode == BUILT_IN_PUTCHAR || fcode == BUILT_IN_PUTS
 	  || fcode == BUILT_IN_PRINTF || fcode == BUILT_IN_FPUTC
@@ -2603,6 +2664,12 @@ expand_builtin (exp, target, subtarget, mode, ignore)
 	return target;
       break;
       
+    case BUILT_IN_STRSTR:
+      target = expand_builtin_strstr (arglist, target, mode);
+      if (target)
+	return target;
+      break;
+      
     case BUILT_IN_MEMCPY:
       target = expand_builtin_memcpy (arglist);
       if (target)
@@ -2696,6 +2763,7 @@ expand_builtin (exp, target, subtarget, mode, ignore)
     case BUILT_IN_PUTS:
     case BUILT_IN_FPUTC:
     case BUILT_IN_FWRITE:
+    case BUILT_IN_STRCHR:
       break;
       
     case BUILT_IN_FPUTS: