From 511a1b523ec0578d0cae75d69fe6c4266929eca6 Mon Sep 17 00:00:00 2001
From: Nick Briggs <nicholas.h.briggs@gmail.com>
Date: Thu, 30 Jan 2025 11:07:29 -0800
Subject: [PATCH] Eliminate extra gotos in common branch tail code (#528)

The implementation of various JUMP opcodes tried to use a common tail
that did a POP and branched to the next opcode. While the extra gotos
probably aren't harmful, neither are they beneficial to code size or speed.
---
 inc/inlineC.h |  4 ++--
 src/xc.c      | 20 ++++----------------
 2 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/inc/inlineC.h b/inc/inlineC.h
index 0e6822e..82f482e 100644
--- a/inc/inlineC.h
+++ b/inc/inlineC.h
@@ -217,7 +217,7 @@
 
 #define FJUMPMACRO(x)                         \
   do {                                        \
-    if (TOPOFSTACK != 0) { goto PopNextop1; } \
+    if (TOPOFSTACK != 0) { POP; nextop1; }    \
     {                                         \
       CHECK_INTERRUPT;                        \
       POP;                                    \
@@ -227,7 +227,7 @@
   } while (0)
 #define TJUMPMACRO(x)                         \
   do {                                        \
-    if (TOPOFSTACK == 0) { goto PopNextop1; } \
+    if (TOPOFSTACK == 0) { POP; nextop1; }    \
     {                                         \
       CHECK_INTERRUPT;                        \
       POP;                                    \
diff --git a/src/xc.c b/src/xc.c
index 52748a9..bfb1b92 100644
--- a/src/xc.c
+++ b/src/xc.c
@@ -814,7 +814,7 @@ nextopcode:
     /******* FJumpx *******/
     case 0262:
     case262 : {
-      if (TOPOFSTACK != 0) { goto PopNextop2; }
+      if (TOPOFSTACK != 0) { POP; nextop2; }
       CHECK_INTERRUPT;
       POP;
       PCMACL += Get_SBYTE_PCMAC1;
@@ -825,7 +825,7 @@ nextopcode:
 
     case 0263:
     case263 : {
-      if (TOPOFSTACK == 0) { goto PopNextop2; }
+      if (TOPOFSTACK == 0) { POP; nextop2; }
       CHECK_INTERRUPT;
       POP;
       PCMACL += Get_SBYTE_PCMAC1;
@@ -836,7 +836,7 @@ nextopcode:
 
     case 0264:
     case264 : {
-      if (TOPOFSTACK != 0) { goto PopNextop2; }
+      if (TOPOFSTACK != 0) { POP; nextop2; }
       CHECK_INTERRUPT;
       PCMACL += Get_SBYTE_PCMAC1;
       nextop0;
@@ -846,7 +846,7 @@ nextopcode:
 
     case 0265:
     case265 : {
-      if (TOPOFSTACK == 0) { goto PopNextop2; }
+      if (TOPOFSTACK == 0) { POP; nextop2; }
       CHECK_INTERRUPT;
       PCMACL += Get_SBYTE_PCMAC1;
       nextop0;
@@ -1261,19 +1261,7 @@ check_interrupt:
       }
     }
   }
-
   nextop0;
-
-/************************************************************************/
-/* Common Jump Tails (they have to jump anyway, so use common Tail) */
-/************************************************************************/
-PopNextop1:
-  POP;
-  nextop1;
-
-PopNextop2:
-  POP;
-  nextop2;
 }
 
 void do_brk(void) {}