Various improvements aimed at getting local optimization regressions fixed:

- Rename _gc to ##gc
- Absolute labels are now supported
- Generate _dispatch-label

basis/compiler/codegen/codegen.factor

@@ -92,9 +92,12 @@ M: ##jump generate-insn word>> [ add-call ] [ %jump ] bi ;
 
 M: ##return generate-insn drop %return ;
 
-M: ##dispatch generate-insn
+M: _dispatch generate-insn
     [ src>> register ] [ temp>> register ] bi %dispatch ;
 
+M: _dispatch-label generate-insn
+    label>> lookup-label %dispatch-label ;
+
 : >slot< ( insn -- dst obj slot tag )
     {
         [ dst>> register ]
@@ -234,7 +237,7 @@ M: ##write-barrier generate-insn
     [ table>> register ]
     tri %write-barrier ;
 
-M: _gc generate-insn drop %gc ;
+M: ##gc generate-insn drop %gc ;
 
 M: ##loop-entry generate-insn drop %loop-entry ;
 

basis/compiler/codegen/fixup/fixup.factor

@@ -16,30 +16,33 @@ SYMBOL: label-table
 
 M: label fixup* compiled-offset >>offset drop ;
 
-TUPLE: label-fixup label class ;
+: offset-for-class ( class -- n )
+    rc-absolute-cell = cell 4 ? compiled-offset swap - ;
+
+TUPLE: label-fixup { label label } { class integer } ;
 
 : label-fixup ( label class -- ) \ label-fixup boa , ;
 
-M: label-fixup fixup*
-    dup class>> rc-absolute?
-    [ "Absolute labels not supported" throw ] when
-    [ class>> ] [ label>> ] bi compiled-offset 4 - swap
-    3array label-table get push ;
-
-TUPLE: rel-fixup class type ;
-
-: rel-fixup ( class type -- ) \ rel-fixup boa , ;
-
 : push-4 ( value vector -- )
     [ length ] [ B{ 0 0 0 0 } swap push-all ] [ underlying>> ] tri
     swap set-alien-unsigned-4 ;
 
+: add-relocation-entry ( type class offset -- )
+      { 0 24 28 } bitfield relocation-table get push-4 ;
+
+M: label-fixup fixup*
+    [ class>> dup offset-for-class ] [ label>> ] bi
+    [ drop [ rt-here ] 2dip add-relocation-entry ]
+    [ 3array label-table get push ]
+    3bi ;
+
+TUPLE: rel-fixup { class integer } { type integer } ;
+
+: rel-fixup ( class type -- ) \ rel-fixup boa , ;
+
 M: rel-fixup fixup*
-    [ type>> ]
-    [ class>> ]
-    [ class>> rc-absolute-cell = cell 4 ? compiled-offset swap - ] tri
-    { 0 24 28 } bitfield
-    relocation-table get push-4 ;
+    [ type>> ] [ class>> dup offset-for-class ] bi
+    add-relocation-entry ;
 
 M: integer fixup* , ;
 

basis/cpu/architecture/architecture.factor

@@ -52,6 +52,7 @@ HOOK: %jump-label cpu ( label -- )
 HOOK: %return cpu ( -- )
 
 HOOK: %dispatch cpu ( src temp -- )
+HOOK: %dispatch-label cpu ( src temp -- )
 
 HOOK: %slot cpu ( dst obj slot tag temp -- )
 HOOK: %slot-imm cpu ( dst obj slot tag -- )

basis/cpu/x86/x86.factor

@@ -79,6 +79,9 @@ M: x86 %return ( -- ) 0 RET ;
 : align-code ( n -- )
     0 <repetition> % ;
 
+M: x86 %dispatch-label ( label -- )
+    0 cell, rc-absolute-cell label-fixup ;
+
 :: (%slot) ( obj slot tag temp -- op )
     temp slot obj [+] LEA
     temp tag neg [+] ; inline

vm/code_block.cpp

@@ -159,7 +159,7 @@ cell compute_relocation(relocation_entry rel, cell index, code_block *compiled)
 	case RT_XT_PIC_TAIL:
 		return (cell)word_xt_pic_tail(untag<word>(ARG));
 	case RT_HERE:
-		return offset + (short)untag_fixnum(ARG);
+		return offset + untag_fixnum(ARG);
 	case RT_THIS:
 		return (cell)(compiled + 1);
 	case RT_STACK_CHAIN: