Perf test case: skip-prologue

This patch add a perf test case on skip-prologue by inserting
breakpoints on two functions many times, in order to exercise
skip-prologue.

gdb/testsuite:

2013-12-15  Yao Qi  <yao@codesourcery.com>

	* gdb.perf/skip-prologue.c: New.
	* gdb.perf/skip-prologue.exp: New.
	* gdb.perf/skip-prologue.py: New.

gdb/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2013-12-15  Yao Qi  <yao@codesourcery.com>
+
+	* gdb.perf/skip-prologue.c: New.
+	* gdb.perf/skip-prologue.exp: New.
+	* gdb.perf/skip-prologue.py: New.
+
 2013-12-13  Joel Brobecker  <brobecker@adacore.com>
 
 	* gdb.ada/arraydim: New testcase.

gdb/testsuite/gdb.perf/skip-prologue.c

@@ -0,0 +1,48 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* GDB will analyze the prologue of functions f1 and f2.  */
+
+struct foo
+{
+  int a[32];
+};
+
+static int
+f1 (void)
+{
+  return 0;
+}
+
+static double
+f2 (int a, long long b, double c, struct foo f)
+{
+  f.a[0] = a + (int) b + c;
+
+  return c + 0.2;
+}
+
+int
+main (void)
+{
+  struct foo f;
+
+  f1 ();
+  f2 (0, 0, 0.1, f);
+
+  return 0;
+}

gdb/testsuite/gdb.perf/skip-prologue.exp

@@ -0,0 +1,69 @@
+# Copyright (C) 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This test case is to test the performance of GDB when it analyzes the
+# function prologue.
+# There is one parameter in this test:
+# - SKIP_PROLOGUE_COUNT is the number that GDB inserts breakpoints on
+#   function f1 and f2 and removes them.
+
+load_lib perftest.exp
+
+if [skip_perf_tests] {
+    return 0
+}
+
+standard_testfile .c
+set executable $testfile
+set expfile $testfile.exp
+
+# make check-perf RUNTESTFLAGS='skip-prologue.exp SKIP_PROLOGUE_COUNT=500'
+if ![info exists SKIP_PROLOGUE_COUNT] {
+    set SKIP_PROLOGUE_COUNT 500
+}
+
+PerfTest::assemble {
+    global srcdir subdir srcfile binfile
+
+    if { [gdb_compile "$srcdir/$subdir/$srcfile" ${binfile} executable {debug}] != "" } {
+	return -1
+    }
+
+    return 0
+} {
+    global binfile
+    global gdb_prompt
+
+    clean_restart $binfile
+
+    if ![runto_main] {
+	fail "Can't run to main"
+	return -1
+    }
+} {
+    global SKIP_PROLOGUE_COUNT
+
+    set test "run"
+    gdb_test_multiple "python SkipPrologue\($SKIP_PROLOGUE_COUNT\).run()" $test {
+	-re "Breakpoint $decimal at \[^\n\]*\n" {
+	    # GDB prints some messages on breakpoint creation.
+	    # Consume the output to avoid internal buffer full.
+	    exp_continue
+	}
+	-re ".*$gdb_prompt $" {
+	    pass $test
+	}
+    }
+}

gdb/testsuite/gdb.perf/skip-prologue.py

@@ -0,0 +1,42 @@
+# Copyright (C) 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This test case is to test the speed of GDB when it is analyzing the
+# function prologue.
+
+from perftest import perftest
+
+class SkipPrologue(perftest.TestCaseWithBasicMeasurements):
+    def __init__(self, count):
+        super(SkipPrologue, self).__init__("skip-prologue")
+        self.count = count
+
+    def _test(self):
+        for _ in range(1, self.count):
+            # Insert breakpoints on function f1 and f2.
+            bp1 = gdb.Breakpoint("f1")
+            bp2 = gdb.Breakpoint("f2")
+            # Remove them.
+            bp1.delete()
+            bp2.delete()
+
+    def warm_up(self):
+        self._test()
+
+    def execute_test(self):
+        for i in range(1, 4):
+            gdb.execute("set code-cache off")
+            gdb.execute("set code-cache on")
+            self.measure.measure(self._test, i)