From fb4b7069842491eb66272587422a1f61d41eb869 Mon Sep 17 00:00:00 2001
From: Dmitry Stogov <dmitry@zend.com>
Date: Tue, 17 Mar 2015 13:51:02 +0300
Subject: [PATCH] Enable GCC global register variables if available

---
 Zend/Zend.m4        | 45 +++++++++++++++++++++++++++++++++++++++++++++
 Zend/zend_execute.c |  2 +-
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/Zend/Zend.m4 b/Zend/Zend.m4
index 16f2d5f923..e12b00d5ef 100644
--- a/Zend/Zend.m4
+++ b/Zend/Zend.m4
@@ -409,3 +409,48 @@ else
     AC_MSG_RESULT(no) 
   fi 
 fi 
+
+AC_ARG_ENABLE(gcc-global-regs,
+[  --disable-gcc-global-regs 
+                          whether to enable GCC global register variables],[
+  ZEND_GCC_GLOBAL_REGS=$enableval
+],[
+  ZEND_GCC_GLOBAL_REGS=yes
+])
+AC_MSG_CHECKING(for global register variables support)
+if test "$ZEND_GCC_GLOBAL_REGS" != "no"; then
+  AC_TRY_COMPILE([
+  ],[
+#if defined(__GNUC__) && defined(i386)
+# define ZEND_VM_FP_GLOBAL_REG "%esi"
+# define ZEND_VM_IP_GLOBAL_REG "%edi"
+#elif defined(__GNUC__) && defined(__x86_64__)
+# define ZEND_VM_FP_GLOBAL_REG "%r14"
+# define ZEND_VM_IP_GLOBAL_REG "%r15"
+#else
+# error "global register variables are not supported"
+#endif
+typedef int (*opcode_handler_t)(void);
+register void *FP  __asm__(ZEND_VM_FP_GLOBAL_REG);
+register const opcode_handler_t *IP __asm__(ZEND_VM_IP_GLOBAL_REG);
+int emu(const opcode_handler_t *ip, void *fp) {
+	const opcode_handler_t *orig_ip = IP;
+	void *orig_fp = FP;
+	IP = ip;
+	FP = fp;
+	while ((*ip)());
+	FP = orig_fp;
+	IP = orig_ip;
+}
+  ], [
+    ZEND_GCC_GLOBAL_REGS=yes
+  ], [
+    ZEND_GCC_GLOBAL_REGS=no
+  ])
+fi
+if test "$ZEND_GCC_GLOBAL_REGS" = "yes"; then
+  AC_DEFINE([HAVE_GCC_GLOBAL_REGS], 1, [Define if the target system has support for global register variables])
+else
+  HAVE_GCC_GLOBAL_REGS=no
+fi
+AC_MSG_RESULT(ZEND_GCC_GLOBAL_REGS)
diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index b24218a2b2..17e68dc55d 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -2049,7 +2049,7 @@ static zend_always_inline void zend_vm_stack_extend_call_frame(zend_execute_data
 }
 /* }}} */
 
-#if HAVE_GCC_GLOBAL_REGS
+#ifdef HAVE_GCC_GLOBAL_REGS
 # if defined(__GNUC__) && defined(i386)
 #  define ZEND_VM_FP_GLOBAL_REG "%esi"
 #  define ZEND_VM_IP_GLOBAL_REG "%edi"
-- 
2.40.0