more size optimizations in BASIC interpreter

2020-07-09 22:58:15 +02:00
1 parent 4871abd79b
commit dbd8c77751
@@ -23,7 +23,7 @@
 	cmd_goto,
 	cmd_run,
 	cmd_if,
-	cmd_restore,
+	do_restore,                        // cmd_restore
 	cmd_gosub,
 	cmd_return,
 	cmd_rem,
@@ -42,7 +42,7 @@
 	cmd_print,
 	cmd_cont,
 	cmd_list,
-	cmd_clr,
+	do_clr,                            // cmd_clr
 	cmd_cmd,
 	cmd_sys,
 	cmd_open,
@@ -3,10 +3,6 @@
 // #LAYOUT# *   *       #IGNORE


-cmd_clr:
+// PLACEHOLDER for completeness - jumptable contains direct address

-	jsr do_clr
-
-	// CLR command does not stop execution (confirmed on a C64)
-
-	jmp end_of_statement
+// CLR command does not stop execution (confirmed on a C64)
@@ -31,7 +31,7 @@ list_loop:
 	// LIST terminates any running program,
 	// because it has fiddled with the current line pointer.
 	// (Confirmed by testing on a C64)
-	jmp shell_main_loop
+	jmp end_of_program

 list_more_lines:

@@ -74,10 +74,9 @@ cmd_load_no_error:

 	ldx CURLIN+1
 	inx
-	beq cmd_load_end                   // branch if direct mode

+	beq_16 end_of_program              // branch if direct mode
+	
+	pha
+	pha
 	jmp execute_line
-
-cmd_load_end:
-
-	jmp shell_main_loop
@@ -9,4 +9,4 @@ cmd_new:

 	// NEW command terminates execution (confirmed on a C64)

-	jmp shell_main_loop
+	jmp end_of_program
@@ -91,4 +91,4 @@ cmd_print_done:

 	// Execute next statement

-	jmp end_of_statement
+	rts
@@ -7,4 +7,6 @@

 cmd_rem:

+	pha
+	pha
 	jmp execute_statements_end_of_line
@@ -3,10 +3,6 @@
 // #LAYOUT# *   *       #IGNORE


-cmd_restore:
+// PLACEHOLDER for completeness - jumptable contains direct address

-	jsr do_restore
-
-	// RESTORE command does not stop execution (confirmed on a C64)
-
-	jmp end_of_statement
+// RESTORE command does not stop execution (confirmed on a C64)
@@ -4,9 +4,15 @@


 cmd_run:
+
 	// RUN clears all variables
 	jsr do_clr
+
 cmd_goto:
+
+	// XXX optimize this: deduplicate last part (and init_oldtxt) with load/verify,
+	// if line number greater than current line - find line backwards
+
 	// Disable Kernal messages
 	lda #$00
 	jsr JSETMSG
@@ -24,4 +30,7 @@ cmd_goto:
 	jmp do_UNDEFD_STATEMENT_error
 !:
 	// Run it!
+	
+	pha
+	pha
 	jmp execute_line
@@ -40,4 +40,4 @@ cmd_save_do: // entry point for BSAVE

 	// Execute next statement

-	jmp end_of_statement
+	rts
@@ -27,4 +27,4 @@ cmd_stop:

 cmd_end:

-	jmp shell_main_loop
+	jmp end_of_program
@@ -60,10 +60,7 @@ cmd_sys_setup_call:
 	plp

 	// Call the routine.
-	jsr USRPOK
-	
-	jmp end_of_statement
-
+	jmp USRPOK

 	//
 	// XXX Temporary ugly hack to support 'SYS PI*656'
@@ -19,7 +19,7 @@

 	cmd_cold,
 	cmd_clear,
-	cmd_dispose
+	varstr_garbage_collect             // cmd_dispose
 )


@@ -39,4 +39,4 @@ cmd_bload:

 	// Execute next statement

-	jmp end_of_statement
+	rts
@@ -5,9 +5,6 @@

 cmd_clear:

-	jsr clear_screen
-
-	// Execute next statement
-
-	jmp end_of_statement
+	// XXX in the future add separate implementation for graphics screen

+	jmp clear_screen
@@ -6,7 +6,9 @@
 cmd_cold:

 	jsr helper_ask_if_sure
-	bcs_16 end_of_statement
+	bcs !+

 	jsr JCLALL                         // for extra safety
 	jmp (vector_reset)                 // hardware CPU vector
+!:
+	rts
@@ -3,11 +3,4 @@
 // #LAYOUT# *   *       #IGNORE


-cmd_dispose:
-
-	jsr varstr_garbage_collect
-
-	// Execute next statement
-
-	jmp end_of_statement
-
+// PLACEHOLDER for completeness - jumptable contains direct address
@@ -42,10 +42,6 @@ cmd_merge_got_params:

 cmd_merge_no_error:

-	// Relink loaded program, clear variables
+	// Relink loaded program, clear variables, execute next statement

-	jsr update_LINKPRG_VARTAB_do_clr
-
-	// Execute next statement
-
-	jmp end_of_statement
+	jmp update_LINKPRG_VARTAB_do_clr
@@ -21,4 +21,4 @@ cmd_old:

 	// Quit

-	jmp shell_main_loop
+	jmp end_of_program
@@ -20,7 +20,7 @@ cmd_fast:

 	lda #$41
 	sta CPU_D6510
-	jmp end_of_statement
+	rts


 #elif CONFIG_MB_ULTIMATE_64
@@ -30,12 +30,12 @@ cmd_fast:
 cmd_slow:

 	sta SCPU_SPEED_NORMAL
-	jmp end_of_statement
+	rts

 cmd_fast:

 	sta SCPU_SPEED_TURBO
-	jmp end_of_statement
+	rts

 #elif CONFIG_PLATFORM_COMMODORE_64

@@ -60,13 +60,13 @@ cmd_fast:
 	lda #$01
 !:
 	sta VIC_CLKRATE
-	jmp end_of_statement
+	rts

 #else

 cmd_slow:

-	nop                                          // to prevent double label
+	nop                                          // just to prevent double label

 	// FALLTROUGH

@@ -3,6 +3,14 @@
 // #LAYOUT# *   *       #IGNORE


+end_of_program:
+
+	// Entry point for commands not wishing to continue
+	pha
+	pha
+
+	// FALLTROUGH
+
 shell_main_loop:

 	// Tell user we are ready
@@ -42,14 +42,24 @@ execute_statements:
 	cmp #$7F
 	bcc_16 execute_statements_var_assign         // not a token - try variable assign

-	cmp #$A6
+	// Move token code to .X
+
+	tax
+
+	// A token - first push the 'end_of_statement' address for RTS
+
+	lda #>(end_of_statement - 1)
+	pha
+	lda #<(end_of_statement - 1)
+	pha
+
+	cpx #$A6
 	bcs execute_statements_extended

 #if !HAS_OPCODES_65C02

 	// Get the jump table entry for it, push it on the stack, and then RTS to start it.

-	tax
 	lda command_jumptable_hi - $80, x
 	pha
 	lda command_jumptable_lo - $80, x
@@ -61,6 +71,7 @@ execute_statements:

 	// Use jumptable to go to the command routine

+	txa
 	asl
 	tax
 	jmp (command_jumptable, x)
@@ -72,14 +83,14 @@ execute_statements_extended:

 	// Support for extended BASIC commands

-	cmp #$CC
+	cpx #$CC
 	beq execute_statements_CC
-	cmp #$CD
+	cpx #$CD
 	beq execute_statements_CD

 	// 'GO' command has a strange token, it is placed after function tokens

-	cmp #$CB                                     
+	cpx #$CB                                     
 	beq_16 cmd_go

 	jmp do_SYNTAX_error