various VOP fixes, simple words compile again

library/compiler/linearizer.factor

@@ -57,14 +57,14 @@ errors prettyprint kernel-internals ;
     [ node-param get ] bind %call ,
 ] "linearizer" set-word-prop
 
-: conditional ( label -- )
+: ifte-head ( label -- )
     in-1  1 %dec-d , 0 %jump-t , ;
 
 : linearize-ifte ( param -- )
     #! The parameter is a list of two lists, each one a dataflow
     #! IR.
     2unlist  <label> [
-        conditional
+        ifte-head
         (linearize) ( false branch )
         <label> dup %jump-label ,
     ] keep %label , ( branch target of BRANCH-T )
@@ -80,6 +80,7 @@ errors prettyprint kernel-internals ;
     #! label/branch pairs.
     in-1
     1 %dec-d ,
+    0 %untag-fixnum ,
     0 %dispatch ,
     <label> ( end label ) swap
     [ <label> dup %target-label ,  cons ] map

library/compiler/vops.factor

@@ -94,6 +94,7 @@ VOP: %indirect
 : %indirect ( vreg obj -- ) >r <vreg> r> f -rot f <%indirect> ;
 
 ! object slot accessors
+! mask off a tag (see also %untag-fixnum)
 VOP: %untag
 : %untag <vreg> dest-vop <%untag> ;
 VOP: %slot
@@ -140,5 +141,8 @@ VOP: %arithmetic-type
 VOP: %tag-fixnum
 : %tag-fixnum <vreg> dest-vop <%tag-fixnum> ;
 
+VOP: %untag-fixnum
+: %untag-fixnum <vreg> dest-vop <%untag-fixnum> ;
+
 : check-dest ( vop reg -- )
     swap vop-dest = [ "invalid VOP destination" throw ] unless ;

library/compiler/x86/fixnum.factor

@@ -4,9 +4,6 @@ IN: compiler
 USING: assembler errors kernel math math-internals memory
 namespaces words ;
 
-: dest/src ( vop -- dest src )
-    dup vop-dest v>operand swap vop-source v>operand ;
-
 : simple-overflow ( dest -- )
     #! If the previous arithmetic operation overflowed, then we
     #! turn the result into a bignum and leave it in EAX. This

library/compiler/x86/generator.factor

@@ -8,6 +8,9 @@ GENERIC: v>operand
 M: integer v>operand address ;
 M: vreg v>operand vreg-n { EAX ECX EDX } nth ;
 
+: dest/src ( vop -- dest src )
+    dup vop-dest v>operand swap vop-source v>operand ;
+
 ! Not used on x86
 M: %prologue generate-node drop ;
 
@@ -44,14 +47,17 @@ M: %untag generate-node ( vop -- )
 M: %tag-fixnum generate-node ( vop -- )
     vop-dest v>operand 3 SHL ;
 
+M: %untag-fixnum generate-node ( vop -- )
+    vop-dest v>operand 3 SHR ;
+
 M: %slot generate-node ( vop -- )
     #! the untagged object is in vop-dest, the tagged slot
-    #! number is in vop-literal.
+    #! number is in vop-source.
-    dup vop-source v>operand swap vop-dest v>operand
+    dest/src
     ! turn tagged fixnum slot # into an offset, multiple of 4
-    over 1 SHR
+    dup 1 SHR
     ! compute slot address in vop-dest
-    tuck ADD
+    dupd ADD
     ! load slot value in vop-dest
     dup unit MOV ;
 
@@ -85,16 +91,21 @@ M: %dispatch generate-node ( vop -- )
     #! Compile a piece of code that jumps to an offset in a
     #! jump table indexed by the fixnum at the top of the stack.
     #! The jump table must immediately follow this macro.
-    vop-source v>operand dup 1 SHR
+    vop-source v>operand
+    ! Multiply by 4 to get a jump table offset
+    dup 2 SHL
+    ! Add to jump table base
     dup HEX: ffff ADD  just-compiled >r f rel-address
+    ! Jump to jump table entry
     unit JMP
+    ! Align for better performance
     compile-aligned
+    ! Fix up jump table pointer
     compiled-offset r> set-compiled-cell ( fixup -- ) ;
 
 M: %type generate-node ( vop -- )
     #! Intrinstic version of type primitive. It outputs an
     #! UNBOXED value in vop-dest.
-    <label> "object" set
     <label> "f" set
     <label> "end" set
     vop-dest v>operand
@@ -104,11 +115,9 @@ M: %type generate-node ( vop -- )
     dup tag-mask AND
     ! Compare with object tag number (3).
     dup object-tag CMP
-    ! Jump if the object stores type info in its header
+    ! Jump if the object doesn't store type info in its header
-    "object" get JE
+    "end" get JNE
     ! It doesn't store type info in its header
-    "end" get JMP
-    "object" get save-xt
     ! It does store type info in its header
     ! Is the pointer itself equal to 3? Then its F_TYPE (9).
     ECX object-tag CMP