dbra tracking and branch improvements

[cyclone68000.git] / OpBranch.cpp

diff --git a/OpBranch.cpp b/OpBranch.cpp
index c37620a..fb4f561 100644 (file)
--- a/OpBranch.cpp
+++ b/OpBranch.cpp
@@ -348,6 +348,7 @@ int OpDbra(int op)
     ot("  and r1,r8,#0x0007\n");\r
     ot("  mov r1,r1,lsl #2\n");\r
     ot("  ldrsh r0,[r7,r1]\n");\r
+    ot("  strb r8,[r7,#0x45] ;@ not polling\n");\r
     ot("  sub r0,r0,#1\n");\r
     ot("  strh r0,[r7,r1]\n");\r
     ot("\n");\r
@@ -418,6 +419,7 @@ int OpBranch(int op)
   int offset=0;\r
   int cc=0;\r
   const char *asr_r11="";\r
+  int pc_reg=0;\r
 \r
   offset=(char)(op&0xff);\r
   cc=(op>>8)&15;\r
@@ -428,7 +430,7 @@ int OpBranch(int op)
 \r
   if (size==2) size=0; // 000 model does not support long displacement\r
   if (size) use=op; // 16-bit or 32-bit\r
-  else use=(op&0xff00)+1; // Use same opcode for all 8-bit branches\r
+  else use=(op&0xff01)+2; // Use same opcode for all 8-bit branches\r
 \r
   if (op!=use) { OpUse(op,use); return 0; } // Use existing handler\r
   OpStart(op,size?0x10:0);\r
@@ -491,8 +493,6 @@ int OpBranch(int op)
     Cycles=18; // always 18\r
   }\r
 \r
-  ot("  add r0,r4,r11%s ;@ r4 = New PC\n",asr_r11);\r
-\r
 #if USE_CHECKPC_CALLBACK && USE_CHECKPC_OFFSETBITS_8\r
   if (offset!=0 && offset!=-1) checkpc=1;\r
 #endif\r
@@ -502,20 +502,48 @@ int OpBranch(int op)
 #if USE_CHECKPC_CALLBACK\r
   if (offset==-1) checkpc=1;\r
 #endif\r
-  if (checkpc) CheckPc();\r
+  if (checkpc)\r
+  {\r
+    ot("  add r0,r4,r11%s ;@ New PC\n",asr_r11);\r
+    CheckPc();\r
+    pc_reg=0;\r
+  }\r
+  else\r
+  {\r
+    ot("  add r4,r4,r11%s ;@ r4 = New PC\n",asr_r11);\r
+    pc_reg=4;\r
+  }\r
+\r
+  if ((op & 1) || size != 0)\r
+  {\r
 #if EMULATE_ADDRESS_ERRORS_JUMP\r
-  ot("  mov r4,r0\n");\r
-  ot("  tst r4,#1 ;@ address error?\n");\r
-  ot("  bne ExceptionAddressError_r_prg_r4\n");\r
+    if (pc_reg!=4)\r
+    {\r
+      ot("  mov r4,r%d\n",pc_reg);\r
+      pc_reg=4;\r
+    }\r
+    if (size)\r
+    {\r
+      ot("  tst r4,#1 ;@ address error?\n");\r
+      ot("  bne ExceptionAddressError_r_prg_r4\n");\r
+    }\r
+    else\r
+    {\r
+      ot("  b ExceptionAddressError_r_prg_r4\n");\r
+    }\r
 #else\r
-  ot("  bic r4,r0,#1\n");\r
+    ot("  bic r4,r%d,#1\n",pc_reg);\r
+    pc_reg=4;\r
 #endif\r
+  }\r
+  if (pc_reg!=4)\r
+    ot("  mov r4,r%d\n",pc_reg);\r
   ot("\n");\r
 \r
   OpEnd(size?0x10:0);\r
 \r
   // since all "DontBranch" code is same for every size, output only once\r
-  if (cc>=2&&(op&0xff00)==0x6700)\r
+  if (cc>=2&&(op&0xff01)==0x6700)\r
   {\r
     ot("BccDontBranch%i%s\n", 8<<size, ms?"":":");\r
     if (size) ot("  add r4,r4,#%d\n",1<<size);\r