From: notaz <notasas@gmail.com>
Date: Tue, 15 Feb 2022 23:20:31 +0000 (+0200)
Subject: drc: try not to end the block prematurely
X-Git-Tag: r24l~507
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a46de54739b25a2fcbfade41b59eebae6c2c86cd;p=pcsx_rearmed.git

drc: try not to end the block prematurely

Fixes: 4919de1e88095f00466f6674323d518fc520b0db

(was not really broken, only load delay detection can't work with
blocks that are too small)
---

diff --git a/libpcsxcore/new_dynarec/new_dynarec.c b/libpcsxcore/new_dynarec/new_dynarec.c
index 95564230..6ade3bb0 100644
--- a/libpcsxcore/new_dynarec/new_dynarec.c
+++ b/libpcsxcore/new_dynarec/new_dynarec.c
@@ -7070,8 +7070,24 @@ static noinline void pass1_disassemble(u_int pagelimit)
 
     /* Is this the end of the block? */
     if (i > 0 && dops[i-1].is_ujump) {
-      if(dops[i-1].rt1==0) { // Continue past subroutine call (JAL)
-        done=2;
+      if (dops[i-1].rt1 == 0) { // not jal
+        int found_bbranch = 0, t = (ba[i-1] - start) / 4;
+        if ((u_int)(t - i) < 64 && start + (t+64)*4 < pagelimit) {
+          // scan for a branch back to i+1
+          for (j = t; j < t + 64; j++) {
+            int tmpop = source[j] >> 26;
+            if (tmpop == 1 || ((tmpop & ~3) == 4)) {
+              int t2 = j + 1 + (int)(signed short)source[j];
+              if (t2 == i + 1) {
+                //printf("blk expand %08x<-%08x\n", start + (i+1)*4, start + j*4);
+                found_bbranch = 1;
+                break;
+              }
+            }
+          }
+        }
+        if (!found_bbranch)
+          done = 2;
       }
       else {
         if(stop_after_jal) done=1;