Add a special OP for retrieving the frame pointer

previousely this was handeled by incoming_reg however the register allocator
doesn't allow to move registers from different reg classes.
Nesting is tested on x86-86, x86 and the interpreter.

attic/jit-rules-alpha.ins

@@ -450,6 +450,11 @@ JIT_OP_RETURN_REG: manual
 		/* Nothing to do here */;
 	}
 
+JIT_OP_RETRIEVE_FRAME_POINTER: note
+	[=reg] -> {
+		alpha_mov(inst,$1,ALPHA_FP);
+	}
+
 JIT_OP_PUSH_INT: note
 	[imm] -> {
 		alpha_li(inst,ALPHA_AT,$1);

jit/jit-dump.c

@@ -794,7 +794,8 @@ void jit_dump_function(FILE *stream, jit_function_t func, const char *name)
 			putc('[', stream);
 			if(func->nested_parent)
 			{
-				fputs("parent_frame", stream);
+				jit_dump_value(stream, func, func->parent_frame, 0);
+				fputs(" : parent_frame", stream);
 				if(value)
 				{
 					fputs(", ", stream);

jit/jit-insn.c

@@ -6292,34 +6292,8 @@ jit_insn_flush_struct(jit_function_t func, jit_value_t value)
 jit_value_t
 jit_insn_get_frame_pointer(jit_function_t func)
 {
-	int reg;
-	jit_value_t value;
-
-	value = jit_value_create(func, jit_type_void_ptr);
-	if(!value)
-	{
-		return 0;
-	}
-
-	for(reg = 0; reg < JIT_NUM_REGS; reg++)
-	{
-		if(jit_reg_flags(reg) & JIT_REG_FRAME)
-		{
-			break;
-		}
-	}
-
-	if(reg < JIT_NUM_REGS)
-	{
-		jit_insn_incoming_reg(func, value, reg);
-	}
-	else
-	{
-		jit_insn_incoming_frame_posn(func, value, 0);
-		value = jit_insn_address_of(func, value);
-	}
-
-	return value;
+	return create_dest_note(func, JIT_OP_RETRIEVE_FRAME_POINTER,
+		jit_type_void_ptr);
 }
 
 static jit_value_t

jit/jit-interp.c

@@ -4892,6 +4892,14 @@ restart_tail:
 		 * Stack management.
 		 ******************************************************************/
 
+		VMCASE(JIT_OP_RETRIEVE_FRAME_POINTER):
+		{
+			/* Move the frame pointer into the register 0 */
+			VM_R0_PTR = frame;
+			VM_MODIFY_PC(1);
+		}
+		VMBREAK;
+
 		VMCASE(JIT_OP_POP_STACK):
 		{
 			/* Pop a specific number of items from the stack */

jit/jit-opcodes.ops

@@ -797,6 +797,7 @@ opcodes(JIT_OP_, "jit_opcode_info_t const jit_opcodes[JIT_OP_NUM_OPCODES]")
 	op_def("outgoing_reg") { op_type(reg) }
 	op_def("outgoing_frame_posn") { op_values(empty, any, int) }
 	op_def("return_reg") { op_type(reg) }
+	op_def("retrieve_frame_pointer") { op_values(any, empty, empty) }
 	op_def("push_int") { op_values(empty, int) }
 	op_def("push_long") { op_values(empty, long) }
 	op_def("push_float32") { op_values(empty, float32) }

jit/jit-rules-arm.ins

@@ -1322,6 +1322,11 @@ JIT_OP_INCOMING_REG, JIT_OP_RETURN_REG: note
 		 */
 	}
 
+JIT_OP_RETRIEVE_FRAME_POINTER: note
+	[=reg] -> {
+		arm_mov_reg_reg(inst, $1, ARM_FP);
+	}
+	
 JIT_OP_PUSH_INT: note
 	[reg] -> {
 		arm_push_reg(inst, $1);

jit/jit-rules-x86-64.ins

@@ -388,6 +388,11 @@ JIT_OP_INCOMING_REG, JIT_OP_RETURN_REG: note
 		 */
 	}
 
+JIT_OP_RETRIEVE_FRAME_POINTER: note
+	[=reg] -> {
+		x86_64_mov_reg_reg_size(inst, $1, X86_64_RBP, 8);
+	}
+
 JIT_OP_PUSH_INT: note
 	[imm] -> {
 		x86_64_push_imm(inst, $1);

jit/jit-rules-x86.ins

@@ -1993,6 +1993,11 @@ JIT_OP_INCOMING_REG, JIT_OP_RETURN_REG: note
 		 */
 	}
 
+JIT_OP_RETRIEVE_FRAME_POINTER: note
+	[=reg] -> {
+		x86_mov_reg_reg(inst, $1, X86_EBP, 4);
+	}
+
 JIT_OP_PUSH_INT: note
 	[imm] -> {
 		x86_push_imm(inst, $1);

jit/jit-rules.c

@@ -172,7 +172,8 @@ int _jit_create_entry_insns(jit_function_t func)
 		{
 			return 0;
 		}
-		func->builder->parent_frame = value;
+
+		jit_function_set_parent_frame(func, value);
 		if(!alloc_incoming_word(func, &passing, value, 0))
 		{
 			return 0;