Turns out that every time the compiler tried to do a stack retraction with asp,

it would flush registers onto the stack. This stops it doing this. Star Trek
goes from 40779 to 40452 bytes.

diff --git a/mach/i80/ncg/table b/mach/i80/ncg/table
index d3e5a0a..87d1d0a 100644 (file)
--- a/mach/i80/ncg/table
+++ b/mach/i80/ncg/table
@@ -53,6 +53,7 @@ smallnconst2   = { INT num; } 2 num. /* Byte-sized negative constant */
 label                  = { ADDR off; } 2 off.
 plabel      = { ADDR off; INT param; } 2 off param.
 m                      = { } 2 cost(0,3) "m".
+comment        = { ADDR str; } 2 "! " str.
 
 SETS
 
@@ -118,7 +119,7 @@ INSTRUCTIONS
    mov  m:wo,reg1:ro                   cost(1, 4).
    mov  reg1:wo,m:ro                   cost(1, 4).
    mvi reg1:wo,const1:ro               cost(2, 7).
-/* nop                                 cost(1, 3).     */
+   nop comment:ro                                      cost(1, 3).
    ora reg1:ro         kills a:cc      cost(1, 4).
    ori const1:ro       kills a:cc      cost(2, 7).
 /* out const1:ro                       cost(2,10).     */
@@ -2161,12 +2162,22 @@ gen 1:
 /* Group 15: Miscellaneous               */
 /******************************************/
 
-pat asp ($1<=0-12) || ($1>=12)
+pat asp $1==0 /* do nothing */
+
+pat asp ($1==2)
+   with regpair
    with STACK
-      uses hlreg={const2,$1}
+      uses hlreg
       gen
-         dad sp
-         sphl.
+         pop hl
+
+pat asp ($1==4)
+   with regpair regpair
+   with STACK
+      uses hlreg
+      gen
+         pop hl
+         pop hl
 
 pat asp ($1<0) && ($1>0-12)
    with STACK
@@ -2175,9 +2186,7 @@ pat asp ($1<0) && ($1>0-12)
       leaving
          asp $1+2
 
-pat asp $1==0 /* do nothing */
-
-pat asp ($1>0) && ($1<12)
+pat asp ($1>4) && ($1<12)
    with STACK
       uses hlreg
       gen
@@ -2185,6 +2194,13 @@ pat asp ($1>0) && ($1<12)
       leaving
          asp $1-2
 
+pat asp
+   with STACK
+      uses hlreg={const2,$1}
+      gen
+         dad sp
+         sphl.
+
 pat ass $1==2
 with hlreg STACK
 gen dad sp