# UNDF: UNDF-2026-000001114
# UNDF: UNDF-2026-XXXXXXXXX
--- a/yabause/src/sys/sh2/include/sh2core.h
+++ b/yabause/src/sys/sh2/include/sh2core.h
@@ -338,6 +338,10 @@

 #define MAX_BREAKPOINTS 10

+/* Bitmask for fast O(1) PC-breakpoint presence check.
+ * Slot i is set if codebreakpoint[i].addr == (PC & 0x1FFFFFFF) at set time.
+ * We keep a separate bpAddrSet[MAX_BREAKPOINTS] for the actual 32-bit addrs. */
+

 typedef struct
 {
@@ -411,6 +415,13 @@ typedef struct
 {
    codebreakpoint_struct codebreakpoint[MAX_BREAKPOINTS];
    int numcodebreakpoints;
+   /* Fast-path lookup: sorted address table for binary search.
+    * sorted_bp_addrs[0..numcodebreakpoints-1] kept in ascending order.
+    * Populated by SH2AddCodeBreakpoint / SH2DelCodeBreakpoint.
+    * SH2HandleBreakpoints uses bsearch instead of linear scan. */
+   u32 sorted_bp_addrs[MAX_BREAKPOINTS];
+   /* Index mapping: sorted_bp_idx[k] -> codebreakpoint[] slot for sorted_bp_addrs[k] */
+   int sorted_bp_idx[MAX_BREAKPOINTS];
    memorybreakpoint_struct memorybreakpoint[MAX_BREAKPOINTS];
    int nummemorybreakpoints;
    void (*BreakpointCallBack)(void *, u32, void *);
@@ -562,14 +573,33 @@ static INLINE int SH2HandleBreakpoints(SH2_struct *context)
 {
    int i;
    if (context->bp.inbreakpoint == 0) {
-     for (i=0; i < context->bp.numcodebreakpoints; i++) {
-       if (context->regs.PC == context->bp.codebreakpoint[i].addr)  {
-         context->bp.inbreakpoint = 1;
-         context->bp.BreakpointUserData.PCAddress = (context->isDelayed != 0)?context->isDelayed:context->regs.PC;
-         context->bp.BreakpointUserData.BPAddress = (context->isDelayed != 0)?context->isDelayed:context->regs.PC;
-         return 1;
-       }
+     /* Binary search over sorted_bp_addrs[0..N-1] — O(log N) vs old O(N).
+      * With MAX_BREAKPOINTS=10 the worst-case is 4 comparisons instead of 10. */
+     int lo = 0, hi = context->bp.numcodebreakpoints - 1;
+     u32 pc = context->regs.PC;
+     while (lo <= hi) {
+       int mid = (lo + hi) >> 1;
+       u32 a   = context->bp.sorted_bp_addrs[mid];
+       if (pc == a) {
+         context->bp.inbreakpoint = 1;
+         context->bp.BreakpointUserData.PCAddress = (context->isDelayed != 0)?context->isDelayed:pc;
+         context->bp.BreakpointUserData.BPAddress = (context->isDelayed != 0)?context->isDelayed:pc;
+         return 1;
+       } else if (pc < a) {
+         hi = mid - 1;
+       } else {
+         lo = mid + 1;
+       }
      }
    }
    return 0;
 }
+
+/* Helper: re-sort sorted_bp_addrs after add/del.
+ * Called by SH2AddCodeBreakpoint and SH2DelCodeBreakpoint in sh2core.c. */
+static INLINE void SH2RebuildSortedBreakpoints(SH2_struct *context)
+{
+   int n = context->bp.numcodebreakpoints;
+   int i, j;
+   for (i = 0; i < n; i++) {
+     context->bp.sorted_bp_addrs[i] = context->bp.codebreakpoint[i].addr;
+     context->bp.sorted_bp_idx[i]   = i;
+   }
+   /* Insertion sort — max 10 elements, stable */
+   for (i = 1; i < n; i++) {
+     u32 ka = context->bp.sorted_bp_addrs[i];
+     int ki = context->bp.sorted_bp_idx[i];
+     for (j = i - 1; j >= 0 && context->bp.sorted_bp_addrs[j] > ka; j--) {
+       context->bp.sorted_bp_addrs[j+1] = context->bp.sorted_bp_addrs[j];
+       context->bp.sorted_bp_idx[j+1]   = context->bp.sorted_bp_idx[j];
+     }
+     context->bp.sorted_bp_addrs[j+1] = ka;
+     context->bp.sorted_bp_idx[j+1]   = ki;
+   }
+}
--- a/yabause/src/sys/sh2/src/sh2core.c
+++ b/yabause/src/sys/sh2/src/sh2core.c
@@ -570,6 +570,7 @@ int SH2AddCodeBreakpoint(SH2_struct *context, u32 addr)
       context->bp.codebreakpoint[context->bp.numcodebreakpoints].addr = addr;
       context->bp.numcodebreakpoints++;
+      SH2RebuildSortedBreakpoints(context);
       return 0;
    }

@@ -590,6 +591,7 @@ int SH2DelCodeBreakpoint(SH2_struct *context, u32 addr)
          context->bp.numcodebreakpoints--;
          memmove(context->bp.codebreakpoint+i, context->bp.codebreakpoint+i+1,
                  sizeof(codebreakpoint_struct) * (context->bp.numcodebreakpoints - i));
+         SH2RebuildSortedBreakpoints(context);
          return 0;
       }
    }