implemented another batch of small floating point routiines

c64/basic/math/bc2b.sgn_FAC1_A.s

@@ -0,0 +1,26 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - evaluate FAC1 sign, to .A
+//
+// Output:
+// - .A - 0 for FAC1 equal 0, 1 for FAC1 > 0, -1 for FAC1 < 0
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 115
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+sgn_FAC1_A:
+
+	lda FAC1_exponent
+	beq !+
+	lda FAC1_sign
+	bne !+
+	lda #$01
+!:
+	rts