duskos

commit b1a35c900a35aa84b4238949f40a62aa07c8d3f4
parent 62bb24b80724a4e54bd419ee8cc3cdfd59bf5070
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Sun, 18 Sep 2022 08:13:04 -0400

cc/gen: simplify VMOp selection

We are no longer tied to a specific op! by making all operations select operands
with "selop^", we can simplify the whole op selection logic. It doesn't matter
anymore whether op1 or op2 is selected.

Diffstat:
M
fs/cc/gen.fs
 | 
19
+++++++++----------
M
fs/cc/vm/commonlo.fs
 | 
9
+--------

2 files changed, 10 insertions(+), 18 deletions(-)
diff --git a/fs/cc/gen.fs b/fs/cc/gen.fs
@@ -195,8 +195,8 @@ ASTIDCNT wordtbl gentbl ( node -- )
     dup rot to Function cursf ( cursf )
     r@ to Declare address ( )
     r@ Node firstchild ?dup if ( node )
-      selop1 gennode ( value in op1 ) op1<>op2
-      selop1 r@ decl>op vmmov,
+      gennode selop^ ( value in op^ )
+      r@ decl>op ( dst in op ) vmmov,
     then rdrop
   then ;
 'w genchildren ( Unit )
@@ -239,19 +239,18 @@ ASTIDCNT wordtbl gentbl ( node -- )
 \ See "Binary op resolution strategy" in opening comment
 :w ( BinaryOp )
   _debug if ." binop: " dup printast nl> then
-  selectedop >r ( node ) >r
+  >r \ V1=node
   r@ bopgentblpre r@ Op opid wexec ( node )
   Node firstchild dup Node nextsibling swap ( n2 n1 )
   over needs2ops? if \ n2 == 2ops
     \ Resolve n2 before n1
     swap gennode \ result in op1
     dup needs2ops? if \ both need 2ops
-      vmop :push rot gennode selop2 vmop :pop else
-      selop2 gennode op1<>op2 then
+      vmop :push rot gennode vmop^ :pop else
+      selop^ gennode then
   else \ nothing special needed, regular resolution
-    selop1 gennode selop2 gennode then
-  selop1 bopgentblpost r> Op opid wexec
-  r> ( selectedop ) if op1<>op2 else selop1 then ;
+    gennode selop^ gennode selop^ then
+  bopgentblpost r> Op opid wexec ;
 \ TODO: this doesn't work with lvalues yet
 :w ( List )
   dup Node :childcount dup 1+ 4 * syspad :allot dup >r ( node len a )
@@ -280,11 +279,11 @@ ASTIDCNT wordtbl gentbl ( node -- )
     vmop loc VM_*CONSTANT = if vmop arg wordfunctype else TYPE_VOID then then
   ( node type ) swap vmop :push rot ( type oparg optype node )
   \ pass arguments
-  selop1 Node firstchild begin ( argnode )
+  Node firstchild begin ( argnode )
     Node nextsibling ?dup while ( argnode )
     dup gennode vmcallarg, repeat
   \ call
-  vmop :pop vmcall, ( type ) if selop1 vmpspop, then ;
+  vmop :pop vmcall, ( type ) if vmpspop, then ;
 :w ( For )
   Node firstchild dup _assert dup gennode ops$ ( exprnode ) \ initialization
   here swap ( loop_addr node )
diff --git a/fs/cc/vm/commonlo.fs b/fs/cc/vm/commonlo.fs
@@ -37,7 +37,7 @@ struct[ VMOp
   \ Initialize op to VM_NONE, "freeing" any resource it held.
   : :init VM_NONE over to loc TYPE_INT swap to type ;
   : :loclo loc $f and ;
-  \ Is op a pointer?
+  \ Is loc a pointer?
   : :pointer? loc $10 and bool ;
   : :isconst? loc VM_CONSTANT = ;
   : :noop# loc VM_NONE = _assert ;
@@ -61,12 +61,9 @@ vmop :self to vmop^ other
 : _sel ['] vmop rebind vmop other ['] vmop^ rebind ;
 : selop1 ( -- ) operands _sel ;
 : selop2 ( -- ) operands VMOp SZ + _sel ;
-: selectedop ( -- n ) \ 0 == Op1 1 == Op2
-  vmop :self operands <> ;
 : selop^ vmop other _sel ;
 
 : .ops
-  selectedop .x1 spc>
   vmop loc .x1 spc> vmop type printtype spc> vmop arg .x spc>
   vmop^ loc .x1 spc> vmop^ type printtype spc> vmop^ arg .x nl> ;
 
@@ -81,7 +78,3 @@ vmop :self to vmop^ other
 : sf+>op ( off -- ) noop# VM_*STACKFRAME to vmop loc to vmop arg ;
 : ps+>op ( off -- ) noop# VM_*ARGSFRAME to vmop loc to vmop arg ;
 : mem>op ( n -- ) noop# VM_*CONSTANT to vmop loc to vmop arg ;
-
-\ Swap op1 and op2 locs/args
-: op1<>op2
-  vmop :push vmop^ :push vmop :pop vmop^ :pop ;