floating point add/subtract written, but not tested yet

c64/basic/,stubs_math/b86a.add_FAC2_FAC1.s

@@ -1,57 +0,0 @@
-// #LAYOUT# STD *       #TAKE
-// #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
-// #LAYOUT# *   BASIC_0 #TAKE
-// #LAYOUT# *   *       #IGNORE
-
-//
-// Math package - add FAC2 to FAC1
-//
-// Input:
-// - .A - must load FAC1 exponent ($61) beforehand to set the zero flag
-//
-// Note:
-// - load FAC2 after FAC1, or mimic the Kernals sign comparison (XXX do we need it?)
-//
-// See also:
-// - [CM64] Computes Mapping the Commodore 64 - page 112
-// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
-// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
-//
-
-// XXX provide implementation
-
-add_FAC2_FAC1:
-
-	// Check if FAC2 is 0; if so, leave FAC1 without changes
-
-	lda FAC2_exponent
-	beq add_FAC2_FAC1_done
-
-	// If FAC1 is 0, just copy FAC2 to FAC1
-
-	lda FAC1_exponent
-	beq_16 mov_FAC2_FAC1
-
-	// Make sure the exponents are aligned
-
-	jsr add_align_exponents
-
-	// Check whether signs are the same
-
-	lda FAC1_sign
-	eor FAC2_sign
-
-	bmi add_FAC2_FAC1_sub              // branch if signs are opposite
-
-
-
-
-
-add_FAC2_FAC1_sub:
-
-	STUB_IMPLEMENTATION()
-
-
-add_FAC2_FAC1_done:
-
-	rts

c64/basic/,stubs_math/b86a.interop

@@ -1,3 +0,0 @@
-This is an important floating point math routine, documented in many places.
-
-XXX - try to find real-life example