Do not start over jit generation if can safely grow buffer size.

* include/lightning/jit_private.h, lib/jit_arm.c, lib/jit_memory.c,
	lib/jit_mips.c, lib/jit_ppc.c, lib/jit_sparc.c, lib/jit_x86.c,
	lib/lightning.c: Do not start over jit generation if can grow
	the code buffer with mremap without moving the base pointer.

ChangeLog

@@ -1,3 +1,10 @@
+2013-03-29 Paulo Andrade <pcpa@gnu.org>
+
+	* include/lightning/jit_private.h, lib/jit_arm.c, lib/jit_memory.c,
+	lib/jit_mips.c, lib/jit_ppc.c, lib/jit_sparc.c, lib/jit_x86.c,
+	lib/lightning.c: Do not start over jit generation if can grow
+	the code buffer with mremap without moving the base pointer.
+
 2013-03-29 Paulo Andrade <pcpa@gnu.org>
 
 	* lib/jit_memory.c: Implement a simple memory allocation wrapper

include/lightning/jit_private.h

@@ -360,6 +360,8 @@ struct jit_compiler {
     } prolog;
     jit_bool_t		  jump;
 #endif
+    /* global flag for code buffer heuristic size computation */
+    jit_word_t		  mult;
 };
 
 #define _jitc				_jit->comp
@@ -485,6 +487,13 @@ extern void jit_alloc(jit_pointer_t*, jit_word_t);
 extern void jit_realloc(jit_pointer_t*, jit_word_t, jit_word_t);
 void jit_free(jit_pointer_t*);
 
+#if HAVE_MREMAP
+#  define jit_remap()		_jit_remap(_jit)
+extern jit_bool_t _jit_remap(jit_state_t*);
+#else
+#  define jit_remap()		0
+#endif
+
 /*
  * Externs
  */

lib/jit_arm.c

@@ -1034,7 +1034,7 @@ _emit_code(jit_state_t *_jit)
 		}							\
 		break
     for (node = _jitc->head; node; node = node->next) {
-	if (_jit->pc.uc >= _jitc->code.end)
+	if (_jit->pc.uc >= _jitc->code.end && !jit_remap())
 	    return (NULL);
 
 	value = jit_classify(node->code);

lib/jit_memory.c

@@ -17,6 +17,7 @@
 
 #include <lightning.h>
 #include <lightning/jit_private.h>
+#include <sys/mman.h>
 
 /*
  * Prototypes
@@ -83,6 +84,29 @@ jit_free(jit_pointer_t *ptr)
     *ptr = NULL;
 }
 
+#if HAVE_MREMAP
+jit_bool_t
+_jit_remap(jit_state_t *_jit)
+{
+    jit_uint8_t		*code;
+    jit_word_t		 length;
+
+    length = _jitc->pool.length * 1024 * (_jitc->mult + 1);
+
+    code = mremap(_jit->code.ptr, _jit->code.length, length, 0, NULL);
+    if (code != MAP_FAILED) {
+	assert(code == _jit->code.ptr);
+	++_jitc->mult;
+	_jit->code.length = length;
+	_jitc->code.end = _jit->code.ptr + _jit->code.length - 64;
+
+	return (1);
+    }
+
+    return (0);
+}
+#endif
+
 static void *
 jit_default_alloc_func(size_t size)
 {

lib/jit_mips.c

@@ -775,7 +775,7 @@ _emit_code(jit_state_t *_jit)
 		}							\
 		break
     for (node = _jitc->head; node; node = node->next) {
-	if (_jit->pc.uc >= _jitc->code.end)
+	if (_jit->pc.uc >= _jitc->code.end && !jit_remap())
 	    return (NULL);
 
 	value = jit_classify(node->code);

lib/jit_ppc.c

@@ -866,7 +866,7 @@ _emit_code(jit_state_t *_jit)
 		}							\
 		break
     for (node = _jitc->head; node; node = node->next) {
-	if (_jit->pc.uc >= _jitc->code.end)
+	if (_jit->pc.uc >= _jitc->code.end && !jit_remap())
 	    return (NULL);
 
 	value = jit_classify(node->code);

lib/jit_sparc.c

@@ -692,7 +692,7 @@ _emit_code(jit_state_t *_jit)
 		}							\
 		break
     for (node = _jitc->head; node; node = node->next) {
-	if (_jit->pc.uc >= _jitc->code.end)
+	if (_jit->pc.uc >= _jitc->code.end && !jit_remap())
 	    return (NULL);
 
 	value = jit_classify(node->code);

lib/jit_x86.c

@@ -1125,7 +1125,7 @@ _emit_code(jit_state_t *_jit)
 		}							\
 		break
     for (node = _jitc->head; node; node = node->next) {
-	if (_jit->pc.uc >= _jitc->code.end)
+	if (_jit->pc.uc >= _jitc->code.end && !jit_remap())
 	    return (NULL);
 
 	value = jit_classify(node->code);

lib/lightning.c

@@ -1455,7 +1455,6 @@ _jit_emit(jit_state_t *_jit)
 {
     jit_pointer_t	 code;
     jit_node_t		*node;
-    jit_int32_t		 mult;
     size_t		 length;
     int			 result;
 
@@ -1464,11 +1463,11 @@ _jit_emit(jit_state_t *_jit)
     jit_optimize();
 
     /* Heuristic to guess code buffer size */
-    mult = 4;
+    _jitc->mult = 4;
 
     _jitc->emit = 1;
 
-    _jit->code.length = _jitc->pool.length * 1024 * mult;
+    _jit->code.length = _jitc->pool.length * 1024 * _jitc->mult;
 
     _jit->code.ptr = mmap(NULL, _jit->code.length,
 			  PROT_EXEC | PROT_READ | PROT_WRITE,
@@ -1485,8 +1484,8 @@ _jit_emit(jit_state_t *_jit)
 		     node->code == jit_code_epilog))
 		    node->flag &= ~jit_flag_patch;
 	    }
-	    ++mult;
+	    ++_jitc->mult;
-	    length = _jitc->pool.length * 1024 * mult;
+	    length = _jitc->pool.length * 1024 * _jitc->mult;
 
 #if !HAVE_MREMAP
 	    munmap(_jit->code.ptr, _jit->code.length);