compiler.cfg.stack-analysis: fix another corner case with ##peek insertion, and fix changed-loc merging

basis/compiler/cfg/stack-analysis/merge/merge.factor

@@ -37,25 +37,25 @@ IN: compiler.cfg.stack-analysis.merge
     '[ _ untranslate-loc ] assoc-map-values ;
 
 : collect-locs ( loc-maps states -- assoc )
-    ! assoc maps locs to sequences of vregs
+    ! assoc maps locs to sequences
     [ untranslate-locs ] 2map
     [ [ keys ] map concat prune ] keep
     '[ dup _ [ at ] with map ] H{ } map>assoc ;
 
-: insert-peek ( predecessor loc -- vreg )
-    '[ _ ^^peek ] add-instructions ;
+: insert-peek ( predecessor loc state -- vreg )
+    '[ _ _ translate-loc ^^peek ] add-instructions ;
 
-: merge-loc ( predecessors vregs loc -- vreg )
+: merge-loc ( predecessors vregs loc state -- vreg )
     ! Insert a ##phi in the current block where the input
     ! is the vreg storing loc from each predecessor block
-    '[ [ ] [ _ insert-peek ] ?if ] 2map
+    '[ [ ] [ _ _ insert-peek ] ?if ] 2map
     dup all-equal? [ first ] [ ^^phi ] if ;
 
 :: merge-locs ( state predecessors states -- state )
     states [ locs>vregs>> ] map states collect-locs
     [| key value |
         key
-        predecessors value key merge-loc
+        predecessors value key state merge-loc
     ] assoc-map
     state translate-locs
     state (>>locs>vregs)
@@ -64,14 +64,17 @@ IN: compiler.cfg.stack-analysis.merge
 : merge-actual-loc ( vregs -- vreg/f )
     dup all-equal? [ first ] [ drop f ] if ;
 
-: merge-actual-locs ( state states -- state )
-    [ [ actual-locs>vregs>> ] map ] keep collect-locs
+:: merge-actual-locs ( state states -- state )
+    states [ actual-locs>vregs>> ] map states collect-locs
     [ merge-actual-loc ] assoc-map [ nip ] assoc-filter
-    over translate-locs
-    >>actual-locs>vregs ;
+    state translate-locs
+    state (>>actual-locs>vregs)
+    state ;
 
 : merge-changed-locs ( state states -- state )
-    [ changed-locs>> ] map assoc-combine >>changed-locs ;
+    [ [ changed-locs>> ] keep untranslate-locs ] map assoc-combine
+    over translate-locs
+    >>changed-locs ;
 
 ERROR: cannot-merge-poisoned states ;
 

basis/compiler/cfg/stack-analysis/stack-analysis-tests.factor

@@ -158,5 +158,49 @@ local-only? off
     stack-analysis
     drop
 
+    3 get instructions>> [ ##peek? ] find nip loc>>
+] unit-test
+
+! Missing ##replace
+[ t ] [
+    [ 0 2over dup not [ [ /mod ] dip ] when ] test-stack-analysis
+    reverse-post-order last
+    instructions>> [ ##replace? ] filter [ loc>> ] map
+    { D 0 D 1 D 2 } set=
+] unit-test
+
+! Inserted ##peeks reference the wrong stack location
+[ t ] [
+    [ [ "B" ] 2dip dup [ [ /mod ] dip ] when ] test-stack-analysis
+    eliminate-dead-code reverse-post-order 3 swap nth
+    instructions>> [ ##peek? ] filter [ loc>> ] map
+    { D 1 D 2 } set=
+] unit-test
+
+[ D 0 ] [
+    V{ T{ ##branch } } 0 test-bb
+
+    V{ T{ ##branch } } 1 test-bb
+
+    V{
+        T{ ##peek f V int-regs 1 D 0 }
+        T{ ##inc-d f 1 }
+        T{ ##branch }
+    } 2 test-bb
+
+    V{
+        T{ ##inc-d f 1 }
+        T{ ##branch }
+    } 3 test-bb
+
+    V{ T{ ##return } } 4 test-bb
+
+    test-diamond
+
+    cfg new 0 get >>entry
+    compute-predecessors
+    stack-analysis
+    drop
+
     3 get instructions>> [ ##peek? ] find nip loc>>
 ] unit-test

basis/compiler/cfg/stack-analysis/stack-analysis.factor

@@ -18,10 +18,10 @@ IN: compiler.cfg.stack-analysis
     [ 2drop t ] [ state get actual-locs>vregs>> at = ] if ;
 
 : save-changed-locs ( state -- )
-    [ changed-locs>> ] [ locs>vregs>> ] bi '[
-        _ at swap 2dup redundant-replace?
+    [ changed-locs>> keys ] [ locs>vregs>> ] bi '[
+        dup _ at swap 2dup redundant-replace?
         [ 2drop ] [ state get untranslate-loc ##replace ] if
-    ] assoc-each ;
+    ] each ;
 
 ERROR: poisoned-state state ;