# HG changeset patch
# User Michael Pavone <pavone@retrodev.com>
# Date 1446086724 25200
# Node ID f2cd380adebe3ea4f8c01e965f48a171dce4221d
# Parent  124a58fdcf3a3d202bbbb5df09a123ce37d3dbd6
Implement TAS

diff -r 124a58fdcf3a -r f2cd380adebe blastem.c
--- a/blastem.c	Wed Oct 28 19:40:01 2015 -0700
+++ b/blastem.c	Wed Oct 28 19:45:24 2015 -0700
@@ -821,6 +821,7 @@
 
 	init_m68k_opts(&opts, rom->map, rom->map_chunks, MCLKS_PER_68K);
 	opts.address_log = address_log;
+	opts.gen.flags |= M68K_OPT_BROKEN_READ_MODIFY;
 	m68k_context *context = init_68k_context(&opts);
 	gen->m68k = context;
 
diff -r 124a58fdcf3a -r f2cd380adebe m68k_core.c
--- a/m68k_core.c	Wed Oct 28 19:40:01 2015 -0700
+++ b/m68k_core.c	Wed Oct 28 19:45:24 2015 -0700
@@ -796,10 +796,9 @@
 	//misc
 	RAW_IMPL(M68K_NOP, translate_m68k_nop),
 	RAW_IMPL(M68K_RESET, translate_m68k_reset),
+	RAW_IMPL(M68K_TAS, translate_m68k_tas),
 
 	//currently unimplemented
-	//M68K_NBCD
-	//M68K_TAS
 	//M68K_TRAPV
 };
 
diff -r 124a58fdcf3a -r f2cd380adebe m68k_core.h
--- a/m68k_core.h	Wed Oct 28 19:40:01 2015 -0700
+++ b/m68k_core.h	Wed Oct 28 19:45:24 2015 -0700
@@ -16,6 +16,8 @@
 #define NATIVE_CHUNK_SIZE ((16 * 1024 * 1024 / NATIVE_MAP_CHUNKS)/2)
 #define MAX_NATIVE_SIZE 255
 
+#define M68K_OPT_BROKEN_READ_MODIFY 1
+
 typedef void (*start_fun)(uint8_t * addr, void * context);
 
 typedef struct {
diff -r 124a58fdcf3a -r f2cd380adebe m68k_core_x86.c
--- a/m68k_core_x86.c	Wed Oct 28 19:40:01 2015 -0700
+++ b/m68k_core_x86.c	Wed Oct 28 19:45:24 2015 -0700
@@ -1312,6 +1312,39 @@
 	translate_m68k_arith(opts, inst, N|Z|V|C, &src_op, &dst_op);
 }
 
+void translate_m68k_tas(m68k_options *opts, m68kinst *inst)
+{
+	code_info *code = &opts->gen.code;
+	host_ea op;
+	translate_m68k_op(inst, &op, opts, 1);
+	if (op.mode == MODE_REG_DIRECT) {
+		cmp_ir(code, 0, op.base, SZ_B);
+	} else {
+		cmp_irdisp(code, 0, op.base, op.disp, SZ_B);
+	}
+	update_flags(opts, N|Z|V0|C0);
+	if (inst->dst.addr_mode == MODE_REG) {
+		cycles(&opts->gen, BUS);
+		if (op.mode == MODE_REG_DIRECT) {
+			bts_ir(code, 7, op.base, SZ_B);
+		} else {
+			bts_irdisp(code, 7, op.base, op.disp, SZ_B);
+		}
+	} else {
+		if (opts->gen.flags & M68K_OPT_BROKEN_READ_MODIFY) {
+			//2 cycles for processing
+			//4 for failed writeback
+			//4 for prefetch
+			cycles(&opts->gen, BUS * 2 + 2);
+		} else {
+			cycles(&opts->gen, 2);
+			bts_ir(code, 7, op.base, SZ_B);
+			m68k_save_result(inst, opts);
+			cycles(&opts->gen, BUS);
+		}
+	}
+}
+
 void op_r(code_info *code, m68kinst *inst, uint8_t dst, uint8_t size)
 {
 	switch(inst->op)
diff -r 124a58fdcf3a -r f2cd380adebe m68k_internal.h
--- a/m68k_internal.h	Wed Oct 28 19:40:01 2015 -0700
+++ b/m68k_internal.h	Wed Oct 28 19:45:24 2015 -0700
@@ -66,6 +66,7 @@
 void translate_m68k_unary(m68k_options *opts, m68kinst *inst, uint32_t flag_mask, host_ea *dst_op);
 void translate_m68k_invalid(m68k_options *opts, m68kinst *inst);
 void translate_m68k_cmp(m68k_options * opts, m68kinst * inst);
+void translate_m68k_tas(m68k_options * opts, m68kinst * inst);
 void translate_m68k_clr(m68k_options * opts, m68kinst * inst);
 void translate_m68k_ext(m68k_options * opts, m68kinst * inst);
 void translate_m68k_abcd_sbcd(m68k_options *opts, m68kinst *inst, host_ea *src_op, host_ea *dst_op);