Add cachegrind support for php-cgi warmups

Cachegrind supports cg_annotate --diff, which makes it much easier to compare
the performance of two patches.

Author: iluuu1994

configure.ac

@@ -751,6 +751,10 @@ AS_VAR_IF([PHP_VALGRIND], [no],,
       AC_DEFINE([HAVE_VALGRIND], [1],
         [Define to 1 if Valgrind is enabled and supported.])])])
 
+if test "$PHP_VALGRIND" = "yes"; then
+  AC_CHECK_HEADERS([valgrind/cachegrind.h])
+fi
+
 dnl General settings.
 dnl ----------------------------------------------------------------------------
 PHP_CONFIGURE_PART(General settings)

sapi/cgi/cgi_main.c

@@ -93,6 +93,9 @@ int __riscosify_control = __RISCOSIFY_STRICT_UNIX_SPECS;
 
 #ifdef HAVE_VALGRIND
 # include "valgrind/callgrind.h"
+# ifdef HAVE_VALGRIND_CACHEGRIND_H
+#  include "valgrind/cachegrind.h"
+# endif
 #endif
 
 #ifndef PHP_WIN32
@@ -2249,6 +2252,10 @@ consult the installation file that came with this distribution, or visit \n\
 								CALLGRIND_STOP_INSTRUMENTATION;
 								/* We're not interested in measuring startup */
 								CALLGRIND_ZERO_STATS;
+# ifdef HAVE_VALGRIND_CACHEGRIND_H
+								CACHEGRIND_STOP_INSTRUMENTATION;
+								/* Zeroing stats is not supported for cachegrind. */
+# endif
 							}
 #endif
 						} else {
@@ -2461,6 +2468,9 @@ consult the installation file that came with this distribution, or visit \n\
 #ifdef HAVE_VALGRIND
 			if (warmup_repeats == 0) {
 				CALLGRIND_START_INSTRUMENTATION;
+# ifdef HAVE_VALGRIND_CACHEGRIND_H
+				CACHEGRIND_START_INSTRUMENTATION;
+# endif
 			}
 #endif
 
@@ -2585,6 +2595,9 @@ consult the installation file that came with this distribution, or visit \n\
 #ifdef HAVE_VALGRIND
 			/* We're not interested in measuring shutdown */
 			CALLGRIND_STOP_INSTRUMENTATION;
+# ifdef HAVE_VALGRIND_CACHEGRIND_H
+			CACHEGRIND_STOP_INSTRUMENTATION;
+# endif
 #endif
 
 			if (!fastcgi) {