[#6] Get rid of extra F register readings in i8080 ALU instructions.

kosarev · Jun 20, 2021 · b977ab8 · b977ab8
1 parent 5b32eb8
commit b977ab8
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Showing 2 changed files with 3 additions and 15 deletions.
diff --git a/tests/tests_i8080 b/tests/tests_i8080
@@ -35,7 +35,6 @@ ce16 aci 0x16
  4   set_pc_on_fetch 0000 -> 0001
  4 get_a 00
  4 get_a 00
- 4 get_f 00
  4 set_a 00 -> 00
  4 set_f 00 -> 44
  4 done
@@ -68,7 +67,6 @@ c616 adi 0x16
  6     mreq_wait 0001
  7   set_pc_on_imm8_read 0001 -> 0002
  7 get_a 00
- 7 get_f 00
  7 set_a 00 -> 16
  7 set_f 00 -> 00
  7 done
@@ -82,7 +80,6 @@ a7 ana a
  4   set_pc_on_fetch 0000 -> 0001
  4 get_a 00
  4 get_a 00
- 4 get_f 00
  4 set_a 00 -> 00
  4 set_f 00 -> 44
  4 done
@@ -101,7 +98,6 @@ e616 ani 0x16
  6     mreq_wait 0001
  7   set_pc_on_imm8_read 0001 -> 0002
  7 get_a 00
- 7 get_f 00
  7 set_a 00 -> 00
  7 set_f 00 -> 44
  7 done
@@ -208,7 +204,6 @@ bc cmp h
  4   set_pc_on_fetch 0000 -> 0001
  4 get_h 00
  4 get_a 00
- 4 get_f 00
  4 set_f 00 -> 54
  4 done
 
@@ -226,7 +221,6 @@ fe16 cpi 0x16
  6     mreq_wait 0001
  7   set_pc_on_imm8_read 0001 -> 0002
  7 get_a 00
- 7 get_f 00
  7 set_f 00 -> 81
  7 done
 
@@ -538,7 +532,6 @@ b3 ora e
  4   set_pc_on_fetch 0000 -> 0001
  4 get_e 00
  4 get_a 00
- 4 get_f 00
  4 set_a 00 -> 00
  4 set_f 00 -> 44
  4 done
@@ -557,7 +550,6 @@ f616 ori 0x16
  6     mreq_wait 0001
  7   set_pc_on_imm8_read 0001 -> 0002
  7 get_a 00
- 7 get_f 00
  7 set_a 00 -> 16
  7 set_f 00 -> 00
  7 done
@@ -700,7 +692,6 @@ f9 sphl
  4   set_pc_on_fetch 0000 -> 0001
  4 get_c 00
  4 get_a 00
- 4 get_f 00
  4 set_a 00 -> 00
  4 set_f 00 -> 54
  4 done
@@ -719,7 +710,6 @@ d616 sui 0x16
  6     mreq_wait 0001
  7   set_pc_on_imm8_read 0001 -> 0002
  7 get_a 00
- 7 get_f 00
  7 set_a 00 -> ea
  7 set_f 00 -> 81
  7 done
@@ -988,7 +978,6 @@ af xra a
  4   set_pc_on_fetch 0000 -> 0001
  4 get_a 00
  4 get_a 00
- 4 get_f 00
  4 set_a 00 -> 00
  4 set_f 00 -> 44
  4 done
@@ -1007,7 +996,6 @@ ee16 xri 0x16
  6     mreq_wait 0001
  7   set_pc_on_imm8_read 0001 -> 0002
  7 get_a 00
- 7 get_f 00
  7 set_a 00 -> 16
  7 set_f 00 -> 00
  7 done

diff --git a/z80.h b/z80.h
@@ -2471,13 +2471,13 @@ class i8080_executor : public internals::executor_base<B> {
 public:
     void do_alu(alu k, fast_u8 n) {
         fast_u8 a = self().on_get_a();
-        fast_u8 f = self().on_get_f();
         flag_op fop;
         fast_u16 t, w;
         fast_u8 b;
         if(((static_cast<unsigned>(k) + 1) & 0x7) < 5) {
             // ADD, ADC, SUB, SBC, CP
-            fast_u8 cfv = (k == alu::adc || k == alu::sbc) ? cf(f) : 0;
+            fast_u8 cfv = (k == alu::adc || k == alu::sbc) ?
+                cf(self().on_get_f()) : 0;
             if(k <= alu::adc) {
                 t = a + n + cfv;
                 fop = flag_op::adc;
@@ -2507,7 +2507,7 @@ class i8080_executor : public internals::executor_base<B> {
         }
         if(k != alu::cp)
             self().on_set_a(mask8(t));
-        self().on_flags_update(f, fop, b, w);
+        self().on_flags_update(/* f= */ 0, fop, b, w);
     }
 
     void on_add_irp_rp(regp rp) {