From 5930cdec6039df7f9dd4f9898770ba66e6868334 Mon Sep 17 00:00:00 2001
From: Andre Weissflog <floooh@gmail.com>
Date: Tue, 9 Jul 2024 20:58:36 +0200
Subject: [PATCH] z80.h: a couple of simplifications I noticed during the zig
 port

---
 chips/z80.h          | 14 +++++++-------
 codegen/z80_desc.yml | 13 ++++---------
 2 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/chips/z80.h b/chips/z80.h
index e9b76b4a..4b34acd9 100644
--- a/chips/z80.h
+++ b/chips/z80.h
@@ -3383,9 +3383,9 @@ uint64_t z80_tick(z80_t* cpu, uint64_t pins) {
         case  707: goto step_next;
         case  708: goto step_next;
         case  709: _wait();_ioread(cpu->wz++);goto step_next;
-        case  710: cpu->dlatch=_gd();goto step_next;
+        case  710: cpu->a=_gd();goto step_next;
         // -- overlapped
-        case  711: cpu->a=cpu->dlatch;goto fetch_next;
+        case  711: goto fetch_next;
         
         //  DC: CALL C,nn (M:6 T:17)
         // -- mread
@@ -4100,12 +4100,12 @@ uint64_t z80_tick(z80_t* cpu, uint64_t pins) {
         case 1112: _wait();_ioread(cpu->bc);goto step_next;
         case 1113: cpu->dlatch=_gd();cpu->wz=cpu->bc+1;goto step_next;
         // -- overlapped
-        case 1114: cpu->hlx[cpu->hlx_idx].h=_z80_in(cpu,cpu->dlatch);goto fetch_next;
+        case 1114: cpu->h=_z80_in(cpu,cpu->dlatch);goto fetch_next;
         
         // ED 61: OUT (C),H (M:2 T:8)
         // -- iowrite
         case 1115: goto step_next;
-        case 1116: _iowrite(cpu->bc,cpu->hlx[cpu->hlx_idx].h);goto step_next;
+        case 1116: _iowrite(cpu->bc,cpu->h);goto step_next;
         case 1117: _wait();cpu->wz=cpu->bc+1;goto step_next;
         case 1118: goto step_next;
         // -- overlapped
@@ -4171,12 +4171,12 @@ uint64_t z80_tick(z80_t* cpu, uint64_t pins) {
         case 1155: _wait();_ioread(cpu->bc);goto step_next;
         case 1156: cpu->dlatch=_gd();cpu->wz=cpu->bc+1;goto step_next;
         // -- overlapped
-        case 1157: cpu->hlx[cpu->hlx_idx].l=_z80_in(cpu,cpu->dlatch);goto fetch_next;
+        case 1157: cpu->l=_z80_in(cpu,cpu->dlatch);goto fetch_next;
         
         // ED 69: OUT (C),L (M:2 T:8)
         // -- iowrite
         case 1158: goto step_next;
-        case 1159: _iowrite(cpu->bc,cpu->hlx[cpu->hlx_idx].l);goto step_next;
+        case 1159: _iowrite(cpu->bc,cpu->l);goto step_next;
         case 1160: _wait();cpu->wz=cpu->bc+1;goto step_next;
         case 1161: goto step_next;
         // -- overlapped
@@ -4677,7 +4677,7 @@ uint64_t z80_tick(z80_t* cpu, uint64_t pins) {
         // -- generic
         case 1471: pins=_z80_refresh(cpu,pins);goto step_next;
         // -- generic
-        case 1472: cpu->step=_z80_optable[cpu->opcode];goto step_next;
+        case 1472: cpu->step=_z80_optable[cpu->opcode]; cpu->addr=cpu->hl;goto step_next;
         // -- overlapped
         case 1473: goto fetch_next;
         
diff --git a/codegen/z80_desc.yml b/codegen/z80_desc.yml
index 6f9c2ddb..7cd91f69 100644
--- a/codegen/z80_desc.yml
+++ b/codegen/z80_desc.yml
@@ -285,13 +285,11 @@ OUT (n),A:
     - { type: mread, ab: $PC++, dst: $WZL, action: $WZH=$A }
     - { type: iowrite, ab: $WZ, db: $A, action: $WZL++ }
 
-# FIXME: ioread can go directly into A
 IN A,(n):
   cond: (x == 3) and (y == 3) and (z == 3)
   mcycles:
     - { type: mread, ab: $PC++, dst: $WZL, action: $WZH=$A }
-    - { type: ioread, ab: $WZ++, dst: $DLATCH }
-    - { type: overlapped, action: $A=$DLATCH }
+    - { type: ioread, ab: $WZ++, dst: $A }
 
 EX (SP),HL:
   cond: (x == 3) and (y == 4) and (z == 3)
@@ -383,13 +381,12 @@ ED NOP:
   cond: (x == 0) or (x == 3) or ((x == 1) and (z == 7) and (y >= 6)) or ((x == 2) and ((z > 3) or (y < 4)))
   mcycles: []
 
-# FIXME: should be RRY (because H/L can't be IXH/IXL etc...)
 IN $RY,(C):
   prefix: ed
   cond: (x == 1) and (y != 6) and (z == 0)
   mcycles:
     - { type: ioread, ab: $BC, dst: $DLATCH, action: $WZ=$BC+1 }
-    - { type: overlapped, action: "$RY=_z80_in(cpu,$DLATCH)" }
+    - { type: overlapped, action: "$RRY=_z80_in(cpu,$DLATCH)" }
 
 IN (C):
   prefix: ed
@@ -399,12 +396,11 @@ IN (C):
     # discard result, only set flags
     - { type: overlapped, action: "_z80_in(cpu,$DLATCH)" }
 
-# FIXME: should be RRY (because H/L can't be IXH/IXL etc...)
 OUT (C),$RY:
   prefix: ed
   cond: (x == 1) and (y != 6) and (z == 1)
   mcycles:
-    - { type: iowrite, ab: $BC, db: $RY, action: $WZ=$BC+1 }
+    - { type: iowrite, ab: $BC, db: $RRY, action: $WZ=$BC+1 }
 
 OUT (C),0:
   prefix: ed
@@ -679,7 +675,6 @@ ddfdcb:
 
 #== INTERRUPT HANDLING =========================================================
 
-# FIXME: last tcycle also needs "cpu->addr = cpu->hl"
 int_im0:
   flags: { special: true }
   mcycles:
@@ -690,7 +685,7 @@ int_im0:
     - { type: generic, tcycles: 1, action: "_wait();cpu->opcode=_z80_get_db(pins)" }
     # combined refresh and branch to loaded instruction cycle
     - { type: generic, tcycles: 1, action: "pins=_z80_refresh(cpu,pins)" }
-    - { type: generic, tcycles: 1, action: "cpu->step=_z80_optable[cpu->opcode]" }
+    - { type: generic, tcycles: 1, action: "cpu->step=_z80_optable[cpu->opcode]; cpu->addr=cpu->hl" }
 
 int_im1:
   flags: { special: true }