Index: codegen/build.tcl
==================================================================
--- codegen/build.tcl
+++ codegen/build.tcl
@@ -4490,43 +4490,10 @@
     method invokeExpanded {arguments flags ec {resultName ""}} {
 	my ExtractVector $arguments
 	my call ${tcl.invoke.expanded} [list $len $ary $flags $ec] $resultName
     }
 
-    # Builder:isBoolean(INT BOOLEAN) --
-    #
-    #	Test if a value is a boolean. Quadcode implementation ('isBoolean').
-    #
-    # Parameters:
-    #	value -	The value to test, as an LLVM value reference.
-    #	name (optional) -
-    #		A name to give to the result value.
-    #
-    # Results:
-    #	An LLVM INT value reference containing a boolean value.
-
-    method isBoolean(INT\040BOOLEAN) {value {name ""}} {
-	# We know we've got one by the type logic; this is trivial
-	my cast(BOOLEAN) [Const true bool] $name
-    }
-
-    # Builder:isBoolean(STRING) --
-    #
-    #	Test if a value is a boolean. Quadcode implementation ('isBoolean').
-    #
-    # Parameters:
-    #	value -	The value to test, as an LLVM value reference.
-    #	name (optional) -
-    #		A name to give to the result value.
-    #
-    # Results:
-    #	An LLVM INT value reference containing a boolean value.
-
-    method isBoolean(STRING) {value {name ""}} {
-	my call ${tcl.isBoolean} [list $value [Const false bool]] $name
-    }
-
     # Builder:isTrue(INT) --
     #
     #	Tests whether a given value will cause 'jumpTrue' to jump;
     #	Quadcode implementation('jumpTrue', 'jumpFalse')
     #

Index: codegen/compile.tcl
==================================================================
--- codegen/compile.tcl
+++ codegen/compile.tcl
@@ -467,11 +467,11 @@
 		    }
 		    my StoreResult $tgt $res
 		}
 		"bitor" - "bitxor" - "bitand" - "lshift" - "rshift" -
 		"add" - "sub" - "mult" - "uminus" - "uplus" - "land" - "lor" -
-		"isBoolean" - "eq" - "neq" - "lt" - "gt" - "le" - "ge" -
+		"eq" - "neq" - "lt" - "gt" - "le" - "ge" -
 		"not" -
 		"streq" - "bitnot" - "strcase" - "strclass" - "strcmp" -
 		"strfind" - "strlen" - "strmap" - "strmatch" - "strrfind" -
 		"strtrim" - "resolveCmd" - "arrayExists" - "directExists" -
 		"arrayElementExists" - "directArrayExists" -

Index: quadcode/pre.tcl
==================================================================
--- quadcode/pre.tcl
+++ quadcode/pre.tcl
@@ -70,11 +70,11 @@
 	    eq expand exists expon extractArray extractCallFrame extractExists
 	    extractFail extractMaybe extractScalar
 	    frameArgs frameDepth
 	    ge gt
 	    initIfNotExists
-	    instanceOf isBoolean
+	    instanceOf
 	    le
 	    listAppend listConcat listIn listIndex listLength listRange
 	    listSet
 	    lshift lt
 	    maptoint mod moveFromCallFrame mult

Index: quadcode/translate.tcl
==================================================================
--- quadcode/translate.tcl
+++ quadcode/translate.tcl
@@ -1101,11 +1101,17 @@
 	    tryCvtToNumeric {	# No effect on value
 	    }
 	    tryCvtToBoolean {	# Push whether we're dealing with a boolean
 		set val [list temp [expr {$depth - 1}]]
 		set res [list temp $depth]
-		my quads isBoolean $res $val
+		set typecode [quadcode::dataType::typeUnion \
+				  $quadcode::dataType::IMPURE \
+				  $quadcode::dataType::BOOLEAN]
+		set v0 [list temp [incr depth -1]]
+		set r $v0
+		my quads [list instanceOf $typecode \
+			   [quadcode::nameOfType $typecode]] $res $val
 	    }
 	    numericType -
 	    resolveCmd -
 	    strlen {		# Unary operations
 		set v0 [list temp [incr depth -1]]

Index: quadcode/types.tcl
==================================================================
--- quadcode/types.tcl
+++ quadcode/types.tcl
@@ -624,11 +624,10 @@
 	dictIterDone -
 	eq -
 	ge -
 	gt -
 	instanceOf -
-	isBoolean -
 	land -
 	le -
 	lor -
 	lt -
 	neq -