From 9d8ea79c7fc763cdb809f35b77e65bdff6c9f469 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Thu, 7 Feb 2019 08:45:20 +0100
Subject: [PATCH] rst 1 now takes an eight-bit parameter, not a 16 bit one.
 Reduces Star Trek again from 43205 to 42339 bytes.

---
 mach/i80/libem/rst.s | 15 +++++++++------
 mach/i80/ncg/table   | 24 ++++++++++++------------
 2 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/mach/i80/libem/rst.s b/mach/i80/libem/rst.s
index b4ad39bee..37025ef17 100644
--- a/mach/i80/libem/rst.s
+++ b/mach/i80/libem/rst.s
@@ -13,16 +13,19 @@
     shld 0x09
     ret
 
-    ! de = [bc+const2] (remember bc is the frame pointer)
+    ! de = [bc+const1] (remember bc is the frame pointer)
 rst1:
     pop h
-    mov e, m
-    inx h
-    mov d, m
+    mov a, m
     inx h
     push h
-    xchg        ! hl = offset
-    dad b
+
+	mov l, a
+	ral
+	sbb a
+	mov h, a
+
+	dad b
     mov e, m
     inx h
     mov d, m
diff --git a/mach/i80/ncg/table b/mach/i80/ncg/table
index 4101d2772..f24c4d39c 100644
--- a/mach/i80/ncg/table
+++ b/mach/i80/ncg/table
@@ -131,7 +131,7 @@ INSTRUCTIONS
 /* rpe					cost(1, 8).	*/
 /* rpo					cost(1, 8).	*/
    rrc			kills a:cc	cost(1, 4).
-   rst	const1:ro kills a:cc cost(1,11).	
+   rst	const1:ro cost(1,11).	
 /* rz					cost(1, 8).	*/
    sbb	reg1:ro 	kills a:cc	cost(1, 4).
 /* sbi	const1:ro 	kills a:cc	cost(2, 7).	*/
@@ -244,24 +244,24 @@ pat ldc					yields {const2,highw($1)}
 					       {const2,loww($1)}
 
 #ifdef USE_I80_RSTS
-   pat lol
+   pat lol sfit($1, 8)
       kills hlreg
       uses hlreg, dereg
       gen
          rst {const1, 1}
-         data2 {const2, $1}
-      yields de
-#else
-   pat lol
-      uses hlreg={const2, $1}, dereg
-      gen
-         dad lb
-         mov e,{m}
-         inx hl
-         mov d,{m}
+         data1 {const1, $1}
       yields de
 #endif
 
+pat lol
+  uses hlreg={const2, $1}, dereg
+  gen
+	 dad lb
+	 mov e,{m}
+	 inx hl
+	 mov d,{m}
+  yields de
+
 pat loe
 uses hlreg
 gen lhld {label,$1}			yields hl