diff --git a/basis/compiler/cfg/dataflow-analysis/dataflow-analysis.factor b/basis/compiler/cfg/dataflow-analysis/dataflow-analysis.factor
index 275a4585b0..dde44fd15d 100644
--- a/basis/compiler/cfg/dataflow-analysis/dataflow-analysis.factor
+++ b/basis/compiler/cfg/dataflow-analysis/dataflow-analysis.factor
@@ -23,7 +23,11 @@ GENERIC# compute-in-set 2 ( bb out-sets dfa -- set )
 M: kill-block compute-in-set 3drop f ;
 
 M:: basic-block compute-in-set ( bb out-sets dfa -- set )
-    bb dfa predecessors [ out-sets at ] map bb dfa join-sets ;
+    ! Only consider initialized sets.
+    bb dfa predecessors
+    [ out-sets key? ] filter
+    [ out-sets at ] map
+    bb dfa join-sets ;
 
 :: update-in-set ( bb in-sets out-sets dfa -- ? )
     bb out-sets dfa compute-in-set
diff --git a/basis/compiler/codegen/codegen.factor b/basis/compiler/codegen/codegen.factor
index d1a09394cd..d1b5558beb 100755
--- a/basis/compiler/codegen/codegen.factor
+++ b/basis/compiler/codegen/codegen.factor
@@ -267,7 +267,7 @@ M: ##alien-global generate-insn
     %alien-global ;
 
 ! ##alien-invoke
-GENERIC: next-fastcall-param ( reg-class -- )
+GENERIC: next-fastcall-param ( rep -- )
 
 : ?dummy-stack-params ( rep -- )
     dummy-stack-params? [ rep-size cell align stack-params +@ ] [ drop ] if ;
@@ -300,7 +300,7 @@ M: reg-class reg-class-full?
     stack-params dup ;
 
 : alloc-fastcall-param ( rep -- n reg-class rep )
-    [ reg-class-of [ get ] [ inc ] [ ] tri ] keep ;
+    [ [ reg-class-of get ] [ reg-class-of ] [ next-fastcall-param ] tri ] keep ;
 
 : alloc-parameter ( parameter -- reg rep )
     c-type-rep dup reg-class-of reg-class-full?
diff --git a/basis/cpu/ppc/ppc.factor b/basis/cpu/ppc/ppc.factor
index a169982445..b8e5bdbe10 100644
--- a/basis/cpu/ppc/ppc.factor
+++ b/basis/cpu/ppc/ppc.factor
@@ -89,11 +89,8 @@ HOOK: reserved-area-size os ( -- n )
 : local@ ( n -- x )
     reserved-area-size param-save-size + + ; inline
 
-: spill-integer@ ( n -- offset )
-    spill-integer-offset local@ ;
-
-: spill-float@ ( n -- offset )
-    spill-float-offset local@ ;
+: spill@ ( n -- offset )
+    spill-offset local@ ;
 
 ! Some FP intrinsics need a temporary scratch area in the stack
 ! frame, 8 bytes in size. This is in the param-save area so it
@@ -275,9 +272,11 @@ M:: ppc %float>integer ( dst src -- )
     fp-scratch-reg 1 0 scratch@ STFD
     dst 1 4 scratch@ LWZ ;
 
-M: ppc %copy ( dst src -- ) MR ;
-
-M: ppc %copy-float ( dst src -- ) FMR ;
+M: ppc %copy ( dst src rep -- )
+    {
+        { int-rep [ MR ] }
+        { double-float-rep [ FMR ] }
+    } case ;
 
 M: ppc %unbox-float ( dst src -- ) float-offset LFD ;
 
@@ -478,11 +477,29 @@ M: ppc %compare-branch (%compare) %branch ;
 M: ppc %compare-imm-branch (%compare-imm) %branch ;
 M: ppc %compare-float-branch (%compare-float) %branch ;
 
-M: ppc %spill-integer ( src n -- ) spill-integer@ 1 swap STW ;
-M: ppc %reload-integer ( dst n -- ) spill-integer@ 1 swap LWZ ;
+: load-from-frame ( dst n rep -- )
+    {
+        { int-rep [ [ 1 ] dip LWZ ] }
+        { single-float-rep [ [ 1 ] dip LFS ] }
+        { double-float-rep [ [ 1 ] dip LFD ] }
+        { stack-params [ [ 0 1 ] dip LWZ [ 0 1 ] dip param@ STW ] }
+    } case ;
 
-M: ppc %spill-float ( src n -- ) spill-float@ 1 swap STFD ;
-M: ppc %reload-float ( dst n -- ) spill-float@ 1 swap LFD ;
+: next-param@ ( n -- x ) param@ stack-frame get total-size>> + ;
+
+: store-to-frame ( src n rep -- )
+    {
+        { int-rep [ [ 1 ] dip STW ] }
+        { single-float-rep [ [ 1 ] dip STFS ] }
+        { double-float-rep [ [ 1 ] dip STFD ] }
+        { stack-params [ [ [ 0 1 ] dip next-param@ LWZ 0 1 ] dip STW ] }
+    } case ;
+
+M: ppc %spill ( src n rep -- )
+    [ spill@ ] dip store-to-frame ;
+
+M: ppc %reload ( dst n rep -- )
+    [ spill@ ] dip load-from-frame ;
 
 M: ppc %loop-entry ;
 
@@ -490,26 +507,11 @@ M: int-regs return-reg drop 3 ;
 M: int-regs param-regs drop { 3 4 5 6 7 8 9 10 } ;
 M: float-regs return-reg drop 1 ;
 
-M: int-regs %save-param-reg drop 1 rot local@ STW ;
-M: int-regs %load-param-reg drop 1 rot local@ LWZ ;
+M:: ppc %save-param-reg ( stack reg rep -- )
+    reg stack local@ rep store-to-frame ;
 
-M: single-float-rep %save-param-reg drop 1 rot local@ STFS ;
-M: single-float-rep %load-param-reg 1 rot local@ LFS ;
-
-M: double-float-rep %save-param-reg drop 1 rot local@ STFD ;
-M: double-float-rep %load-param-reg 1 rot local@ LFD ;
-
-M: stack-params %load-param-reg ( stack reg rep -- )
-    drop [ 0 1 rot local@ LWZ 0 1 ] dip param@ STW ;
-
-: next-param@ ( n -- x ) param@ stack-frame get total-size>> + ;
-
-M: stack-params %save-param-reg ( stack reg rep -- )
-    #! Funky. Read the parameter from the caller's stack frame.
-    #! This word is used in callbacks
-    drop
-    [ 0 1 ] dip next-param@ LWZ
-    [ 0 1 ] dip local@ STW ;
+M:: ppc %load-param-reg ( stack reg rep -- )
+    reg stack local@ rep load-from-frame ;
 
 M: ppc %prepare-unbox ( -- )
     ! First parameter is top of stack