Add FCOMP

STATUS.md

@@ -236,7 +236,7 @@ Floating point mathematical routines - not official, but well known and broadly
 | `$BC3C`   | `convert_A_to_FAC1`    | DONE     |                                                    |
 | `$BC44`   | `convert_i16_to_FAC1`  | DONE     |                                                    |
 | `$BC58`   | `abs_FAC1`             | NOT DONE |                                                    |
-| `$BC5B`   | `FCOMP`                | NOT DONE | compare FAC1 with RAM location                     |
+| `$BC5B`   | `FCOMP`                | DONE     |                                                    |
 | `$BC9B`   | `QINT`                 | NOT DONE | convert FAC1 to 32 bit signed integer              |
 | `$BCCC`   | `int_FAC1`             | NOT DONE |                                                    |
 | `$BCF3`   | `FIN`                  | NOT DONE | imports string to FAC1, ignores spaces             |

src/basic/,stubs_math/bc5b.FCOMP.s

@@ -1,30 +0,0 @@
-;; #LAYOUT# STD *       #TAKE
-;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
-;; #LAYOUT# *   BASIC_0 #TAKE
-;; #LAYOUT# *   *       #IGNORE
-
-;
-; Math package - compare FAC1 with RAM location
-;
-; Input:
-; - .A - address low byte
-; - .Y - address high byte
-;
-; Output:
-; - .A - $00 for equal, $01 for FAC1 > RAM, $FF for FAC1 < RAM
-; - flags N/Z, depending on whether FAC1 is 0, positive, or negative
-;
-; Notes:
-; - uses vector at $24, leaves FAC1 and FAC2 unchanged (Codebase64)
-;
-; 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
-;
-
-; XXX provide implementation
-
-FCOMP:
-
-	+STUB_IMPLEMENTATION

src/basic/math/FCOMP.s

@@ -0,0 +1,92 @@
+;; #LAYOUT# STD *       #TAKE
+;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
+;; #LAYOUT# *   BASIC_0 #TAKE
+;; #LAYOUT# *   *       #IGNORE
+
+;
+; Math package - compare FAC1 with RAM location
+;
+; Input:
+; - .A - address low byte
+; - .Y - address high byte
+;
+; Output:
+; - .A - $00 for equal, $01 for FAC1 > RAM, $FF for FAC1 < RAM
+; - flags N/Z, depending on whether FAC1 is 0, positive, or negative
+;
+; Notes:
+; - uses vector at $24, leaves FAC1 and FAC2 unchanged (Codebase64)
+;
+; 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
+;
+
+
+FCOMP: 
+    sta INDEX+2
+    sty INDEX+3
+
+    jsr sgn_FAC1_A          ; Set N/Z flag for FAC1 and store on stack
+    php
+
+    ldy #$01
+    lda #$7F                ; Expand sign of RAM float into A as $FF or $00
+    cmp (INDEX+2),Y
+    adc #$80
+    cmp FAC1_sign
+    bne FCOMP_greater_than  ; FAC < or > RAM, will be swapped to correct
+
+    dey
+    lda (INDEX+2),Y         ; Exponent of RAM float into A
+    cmp FAC1_exponent
+    bcc FCOMP_greater_than  ; FAC1 > RAM
+    bne FCOMP_less_than
+
+    cmp #$00
+    beq FCOMP_equal         ; FAC1 = RAM = 0
+
+    iny
+    lda (INDEX+2),Y
+    ora #$80                ; Set highest bit of mantissa (0.5)
+    cmp FAC1_mantissa
+    bcc FCOMP_greater_than
+    bne FCOMP_less_than
+    iny
+    lda (INDEX+2),Y
+    cmp FAC1_mantissa+1
+    bcc FCOMP_greater_than
+    bne FCOMP_less_than
+    iny
+    lda (INDEX+2),Y
+    cmp FAC1_mantissa+2
+    bcc FCOMP_greater_than
+    bne FCOMP_less_than
+    iny
+    lda (INDEX+2),Y
+    cmp FAC1_mantissa+3
+    bcc FCOMP_greater_than
+    bne FCOMP_less_than
+
+FCOMP_equal:
+    lda #$00
+    plp
+    rts
+
+
+FCOMP_less_than:
+    lda #$FF
+    cmp FAC1_sign
+    bne @1
+    lda #$01
+@1: plp
+    rts
+
+FCOMP_greater_than:
+    lda #$01
+    cmp FAC1_sign
+    bcs @1
+    lda #$FF
+@1: plp
+    rts

src/basic/math/bc5b.FCOMP.jmp.s

@@ -0,0 +1,8 @@
+;; #LAYOUT# STD *       #TAKE
+;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
+;; #LAYOUT# *   BASIC_0 #TAKE
+;; #LAYOUT# *   *       #IGNORE
+
+; Just a compatibility jump - our routine is longer than original one
+
+	jmp FCOMP

strings/2DA52C6900852E20

@@ -0,0 +1,3 @@
+$2D + LDA $2C + ADC #$00 + STA $2E + JSR
+
+Fragment of updating well known pointers in the zero page

strings/6085248425

@@ -0,0 +1,3 @@
+$60 + STA $24 + STA $25
+
+Fragment of storing to well known pointer in zero page

strings/B1240980C562

@@ -0,0 +1,3 @@
+LDA ($24),Y + ORA $#80 + CMP $62
+
+Load using well knownn pointer in zero page, set sign bit and compare with byte in FAC1 mantissa

strings/B124C564

@@ -0,0 +1,3 @@
+LDA ($24),Y + CMP $64
+
+Load using well known zero page pointer and compare with FAC1 mantissa byte in zero page

strings/C8B124C5

@@ -0,0 +1,3 @@
+INY + LDA ($24),Y + CMP zp
+
+Loop fragment with well known zero page pointer address

strings/C8B124C563

@@ -0,0 +1,3 @@
+INY + LDA ($24),Y + CMP $63
+
+Load using well known pointer in zero page and compare with mantissa byte in FAC1

strings/E52BAAA538E52C20CD

@@ -0,0 +1,3 @@
+SBC $2B + TAX + LDA $38 + SBC $2C + JSR $CD..
+
+Fragment of decreasing well known pointer in zero page

testsuite/unit/math.vs

@@ -105,4 +105,118 @@ print "COMPARE"
 compare $61 $67 $1001
 print "END"
 
+print "TEST: mov MEM FAC1 const 1.0"
+fill $61 $67 FF FF FF FF FF AA
+fill $70 $70 CD
+r A=$BC
+r Y=$B9
+r PC=$BBA2
+ret
+fill $1001 $1006 81 80 00 00 00 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: mov MEM FAC1 const -0.5"
+fill $61 $67 FF FF FF FF FF AA
+fill $70 $70 CD
+r A=$E0
+r Y=$B9
+r PC=$BBA2
+ret
+fill $1001 $1006 80 80 00 00 00 FF
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: FCOMP 1.0 == 1.0"
+r A=$BC
+r Y=$B9
+r PC=$BBA2
+ret
+r A=$BC
+r Y=$B9
+r PC=$BC5B
+ret
+print "CHECK A==0"
+r
+
+print "TEST: FCOMP 1.0 > 0.5"
+r A=$BC
+r Y=$B9
+r PC=$BBA2
+ret
+r A=$11
+r Y=$BF
+r PC=$BC5B
+ret
+print "CHECK A==1"
+r
+
+print "TEST: FCOMP 0.5 < 1.0"
+r A=$11
+r Y=$BF
+r PC=$BBA2
+ret
+r A=$BC
+r Y=$B9
+r PC=$BC5B
+ret
+print "CHECK A==255"
+r
+
+print "TEST: FCOMP -0.5 < 1.0"
+r A=$E0
+r Y=$B9
+r PC=$BBA2
+ret
+r A=$BC
+r Y=$B9
+r PC=$BC5B
+ret
+print "CHECK A==255"
+r
+
+print "TEST: FCOMP 10.0 > -0.5"
+r A=$F9
+r Y=$BA
+r PC=$BBA2
+ret
+r A=$E0
+r Y=$B9
+r PC=$BC5B
+ret
+print "CHECK A==1"
+r
+
+print "TEST: FCOMP 0.9970194103661925 < 0.9970194105990231"
+fill $1001 $1005 80 7F 3C AA 01
+r A=$01
+r Y=$10
+r PC=$BBA2
+ret
+fill $1006 $100A 80 7F 3C AA 02
+r A=$06
+r Y=$10
+r PC=$BC5B
+ret
+print "CHECK A==255"
+r
+
+print "TEST: FCOMP 0.0 = 0.0"
+fill $1001 $1005 00 7F 3C AA 01
+r A=$01
+r Y=$10
+r PC=$BBA2
+ret
+fill $1006 $100A 00 7F 3C AA 02
+r A=$06
+r Y=$10
+r PC=$BC5B
+ret
+print "CHECK A==0"
+r
+
 q

testsuite/unit/testresults.cc

@@ -20,6 +20,26 @@ int main()
             } else if (line.starts_with("  print \"COMPARE")) {
                 getline(file, line);
                 in_compare = true;
+            } else if (line.starts_with("  print \"CHECK")) {
+                std::string cmp = line.substr(15, line.size() - 16);
+                std::string reg = cmp.substr(0, 1);
+                std::string op = cmp.substr(1, 2);
+                int value = std::stoi(cmp.substr(3, line.size() - 3));
+                if (op == "==") {
+                    getline(file, line);
+                    getline(file, line);
+                    getline(file, line);
+                    if (reg == "A") {
+                        int A_val = std::stoi(line.substr(7, 2), 0, 16);
+                        if (A_val != value) {
+                            std::cout << "FAIL: A != " << value << " (was " << A_val << ")" << std::endl;
+                            failed = true;
+                        }
+                    }
+                } else {
+                    std::cout << "ERROR: Unknown operator for check" << std::endl;
+                    failed = true;
+                }
             } else if (line.starts_with("  print \"END")) {
                 in_compare = false;
             }