@@ -1457,6 +1457,55 @@ gimple_fold_builtin_strncpy (gimple_stmt_iterator *gsi,
return true;
}
+/* Simplify strchr (str, 0) into str + strlen (str).
+ In general strlen is significantly faster than strchr
+ due to being a simpler operation. */
+static bool
+gimple_fold_builtin_strchr (gimple_stmt_iterator *gsi)
+{
+ gimple *stmt = gsi_stmt (*gsi);
+ tree str = gimple_call_arg (stmt, 0);
+ tree c = gimple_call_arg (stmt, 1);
+ location_t loc = gimple_location (stmt);
+
+ if (optimize_function_for_size_p (cfun))
+ return false;
+
+ if (!integer_zerop (c) || !gimple_call_lhs (stmt))
+ return false;
+
+ tree len;
+ tree strlen_fn = builtin_decl_implicit (BUILT_IN_STRLEN);
+
+ if (!strlen_fn)
+ return false;
+
+ /* Create newstr = strlen (str). */
+ gimple_seq stmts = NULL;
+ gimple *new_stmt = gimple_build_call (strlen_fn, 1, str);
+ gimple_set_location (new_stmt, loc);
+ if (gimple_in_ssa_p (cfun))
+ len = make_ssa_name (size_type_node);
+ else
+ len = create_tmp_reg (size_type_node);
+ gimple_call_set_lhs (new_stmt, len);
+ gimple_seq_add_stmt_without_update (&stmts, new_stmt);
+
+ /* Create (str p+ strlen (str)). */
+ new_stmt = gimple_build_assign (gimple_call_lhs (stmt),
+ POINTER_PLUS_EXPR, str, len);
+ gimple_seq_add_stmt_without_update (&stmts, new_stmt);
+ gsi_replace_with_seq_vops (gsi, stmts);
+ /* gsi now points at the assignment to the lhs, get a
+ stmt iterator to the strlen.
+ ??? We can't use gsi_for_stmt as that doesn't work when the
+ CFG isn't built yet. */
+ gimple_stmt_iterator gsi2 = *gsi;
+ gsi_prev (&gsi2);
+ fold_stmt (&gsi2);
+ return true;
+}
+
/* Simplify a call to the strcat builtin. DST and SRC are the arguments
to the call.
@@ -2898,6 +2947,8 @@ gimple_fold_builtin (gimple_stmt_iterator *gsi)
gimple_call_arg (stmt, 1));
case BUILT_IN_STRNCAT:
return gimple_fold_builtin_strncat (gsi);
+ case BUILT_IN_STRCHR:
+ return gimple_fold_builtin_strchr (gsi);
case BUILT_IN_FPUTS:
return gimple_fold_builtin_fputs (gsi, gimple_call_arg (stmt, 0),
gimple_call_arg (stmt, 1), false);
@@ -86,9 +86,9 @@ main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
@@ -57,9 +57,9 @@ main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 3 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
@@ -31,9 +31,9 @@ main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 3 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 4 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
@@ -5,9 +5,9 @@
#define USE_GNU
#include "strlenopt-22.c"
-/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 1 "strlen" } } */
@@ -21,4 +21,5 @@ main (void)
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
@@ -48,9 +48,9 @@ main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 2 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
@@ -40,11 +40,11 @@ main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "\\*r_\[0-9\]* = 0;" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "return 3;" 1 "optimized" } } */
@@ -98,10 +98,10 @@ main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "strlen \\(" 3 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strlen \\(" 5 "strlen" } } */
/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcpy \\(" 1 "strlen" } } */
/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
-/* { dg-final { scan-tree-dump-times "strchr \\(" 3 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
/* { dg-final { scan-tree-dump-times "return 4;" 1 "optimized" } } */