From: Kazu Hirata <kazu@cs.umass.edu>
Date: Wed, 2 Jun 2004 18:41:40 +0000 (+0000)
Subject: re PR tree-optimization/15738 ([tree-ssa] Convert strrchr(s, c) to strchr(s, c) if... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=91fa0e3de67af533eeeb8ef494a2bb66187570c1;p=gcc.git

re PR tree-optimization/15738 ([tree-ssa] Convert strrchr(s, c) to strchr(s, c) if c is known to be 0)

	PR tree-optimization/15738.
	* builtins.c (fold_builtin_strchr): Transform
	strrchr (s, '\0') to strchr (s, '\0').

From-SVN: r82572
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bb675bb3fea..8d22422d993 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2004-06-02  Kazu Hirata  <kazu@cs.umass.edu>
+
+	PR tree-optimization/15738.
+	* builtins.c (fold_builtin_strchr): Transform
+	strrchr (s, '\0') to strchr (s, '\0').
+
 2004-06-02  Steven Bosscher  <stevenb@suse.de>
 
 	* i386.c (ix86_adjust_cost): Don't increase the cost for
diff --git a/gcc/builtins.c b/gcc/builtins.c
index e44ad61b7b2..e2651866d63 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -7123,6 +7123,21 @@ fold_builtin_strchr (tree exp, bool actually_strrchr)
 						 ssize_int (r - p1))));
 	}
 
+      if (actually_strrchr)
+	{
+	  tree fn;
+
+	  if (!integer_zerop (s2))
+	    return 0;
+
+	  fn = implicit_built_in_decls[BUILT_IN_STRCHR];
+	  if (!fn)
+	    return 0;
+
+	  /* Transform strrchr(s1, '\0') to strchr(s1, '\0').  */
+	  return build_function_call_expr (fn, arglist);
+	}
+
       return 0;
     }
 }