From 56dc6ecb70e6fc76d32d6a7194acb273b76bfe0e Mon Sep 17 00:00:00 2001
From: David Guillen Fandos
Date: Mon, 8 Mar 2021 18:44:03 +0100
Subject: Remove libco

This removes libco and all the usages of it (+pthreads).
Rewired all dynarecs and interpreter to return after every frame so that
libretro can process events. This required to make dynarec re-entrant.

Dynarecs were updated to check for new frame on every update (IRQ, cycle
exhaustion, I/O write, etc). The performance impact of doing so should
be minimal (and definitely outweight the libco gains). While at it,
fixed small issues to get a bit more perf: arm dynarec was not idling
correctly, mips was using stack when not needed, etc.

Tested on PSP (mips), OGA (armv7), Linux (x86 and interpreter). Not
tested on Android though.
---
 cpu.c | 47 +++++++++++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 22 deletions(-)

(limited to 'cpu.c')

diff --git a/cpu.c b/cpu.c
index c555c0b..a15b432 100644
--- a/cpu.c
+++ b/cpu.c
@@ -1562,8 +1562,10 @@ u32 cpu_modes_cpsr[7] = { 0x10, 0x11, 0x12, 0x13, 0x17, 0x1B, 0x1F };
 // When switching modes set spsr[new_mode] to cpsr. Modifying PC as the
 // target of a data proc instruction will set cpsr to spsr[cpu_mode].
 
-u32 initial_reg[64];
-u32 *reg = initial_reg;
+#ifndef HAVE_DYNAREC
+u32 reg[64];
+#endif
+
 u32 spsr[6];
 
 // ARM/Thumb mode is stored in the flags directly, this is simpler than
@@ -1672,9 +1674,17 @@ void execute_arm(u32 cycles)
   if(!pc_address_block)
     pc_address_block = load_gamepak_page(pc_region & 0x3FF);
 
+  cycles_remaining = cycles;
   while(1)
   {
-    cycles_remaining = cycles;
+    /* Do not execute until CPU is active */
+    while(reg[CPU_HALT_STATE] != CPU_ACTIVE) {
+       cycles_remaining = update_gba();
+
+       if (reg[COMPLETED_FRAME])
+          return;
+    }
+
     pc = reg[REG_PC];
     extract_flags();
 
@@ -3292,7 +3302,9 @@ skip_instruction:
     } while(cycles_remaining > 0);
 
     collapse_flags();
-    cycles = update_gba();
+    cycles_remaining = update_gba();
+    if (reg[COMPLETED_FRAME])
+       return;
     continue;
 
     do
@@ -4261,19 +4273,21 @@ thumb_loop:
     } while(cycles_remaining > 0);
 
     collapse_flags();
-    cycles = update_gba();
+    cycles_remaining = update_gba();
+    if (reg[COMPLETED_FRAME])
+      return;
     continue;
 
     alert:
 
-    if(cpu_alert == CPU_ALERT_IRQ)
-      cycles = cycles_remaining;
-    else
-    {
+    if(cpu_alert != CPU_ALERT_IRQ) {
       collapse_flags();
 
-      while(reg[CPU_HALT_STATE] != CPU_ACTIVE)
-        cycles = update_gba();
+      while(reg[CPU_HALT_STATE] != CPU_ACTIVE) {
+        cycles_remaining = update_gba();
+        if (reg[COMPLETED_FRAME])
+          return;
+      }
     }
   }
 }
@@ -4298,17 +4312,6 @@ void init_cpu(void)
   reg_mode[MODE_SUPERVISOR][5] = 0x03007FE0;
 }
 
-void move_reg(u32 *new_reg)
-{
-  u32 i;
-
-  for(i = 0; i < 32; i++)
-    new_reg[i] = reg[i];
-
-  reg = new_reg;
-}
-
-
 #define cpu_savestate_builder(type)   \
 void cpu_##type##_savestate(void)     \
 {                                     \
-- 
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