do not start new basic block on the bytecode mark

fix offset for the last mark

ChangeLog

@@ -1,3 +1,12 @@
+2007-11-17  Aleksey Demakov  <ademakov@gmail.com>
+
+	* jit/jit-insn.c (jit_insn_mark_offset): do not start new block
+	on the bytecode mark. If a mark goes just after another mark then
+	replace the old mark rather than add the new.
+
+	* jit/jit-cache.c (_jit_cache_get_bytecode)
+	(_jit_cache_get_native): fix offset for the last bytecode mark.
+
 2007-11-13  Aleksey Demakov  <ademakov@gmail.com>
 
 	* tools/Makefile.am (noinst_HEADERS): add gen-apply-macosx.h

jit/jit-cache.c

@@ -1323,7 +1323,8 @@ unsigned long _jit_cache_get_native(jit_cache_t cache, void *start,
 		}
 		prevNativeOfs = nativeOfs;
 	}
-	return JIT_CACHE_NO_OFFSET;
+
+	return exact ? JIT_CACHE_NO_OFFSET : prevNativeOfs;
 }
 
 unsigned long _jit_cache_get_bytecode(jit_cache_t cache, void *start,
@@ -1350,7 +1351,8 @@ unsigned long _jit_cache_get_bytecode(jit_cache_t cache, void *start,
 		}
 		prevOfs = ofs;
 	}
-	return JIT_CACHE_NO_OFFSET;
+
+	return exact ? JIT_CACHE_NO_OFFSET : prevOfs;
 }
 
 unsigned long _jit_cache_get_size(jit_cache_t cache)

jit/jit-insn.c

@@ -8013,15 +8013,35 @@ int jit_insn_move_blocks_to_start
 @*/
 int jit_insn_mark_offset(jit_function_t func, jit_int offset)
 {
-#if 1
-	if(!jit_insn_new_block(func))
+	jit_block_t block;
+	jit_insn_t last;
+	jit_value_t value;
+
+	/* Ensure that we have a builder for this function */
+	if(!_jit_function_ensure_builder(func))
 	{
 		return 0;
 	}
-#endif
-	return create_unary_note(func, JIT_OP_MARK_OFFSET,
-					   	     jit_value_create_nint_constant
-					   			(func, jit_type_int, offset));
+
+	value = jit_value_create_nint_constant(func, jit_type_int, offset);
+	if (!value)
+	{
+		return 0;
+	}
+
+	/* If the previous instruction is mark offset too
+	   then just replace the offset value in place --
+	   we are not interested in bytecodes that produce
+	   no real code. */
+	block = func->builder->current_block;
+	last = _jit_block_get_last(block);
+	if (last && last->opcode == JIT_OP_MARK_OFFSET)
+	{
+		last->value1 = value;
+		return 1;
+	}
+
+	return create_unary_note(func, JIT_OP_MARK_OFFSET, value);
 }
 
 /* Documentation is in jit-debugger.c */