From 5d8241fe2c101a5054695b56d06c148da76fbf45 Mon Sep 17 00:00:00 2001
From: Rikard Nordgren <hrn@posteo.net>
Date: Sun, 6 Apr 2025 12:33:08 +0200
Subject: [PATCH] Fix broken div10_FAC1

Also add some unit tests for div_FAC1_FAC2
---
 src/basic/math/bafe.div10_FAC1_p.s |  15 ++--
 strings/842000000020               |   1 +
 strings/A2BB4C12BB                 |   3 +
 strings/A84CA2B34C                 |   3 +
 testsuite/unit/math.vs             | 107 +++++++++++++++++++++++++++++
 5 files changed, 120 insertions(+), 9 deletions(-)
 create mode 100644 strings/842000000020
 create mode 100644 strings/A2BB4C12BB
 create mode 100644 strings/A84CA2B34C

diff --git a/src/basic/math/bafe.div10_FAC1_p.s b/src/basic/math/bafe.div10_FAC1_p.s
index a13dd084..4a83d10f 100644
--- a/src/basic/math/bafe.div10_FAC1_p.s
+++ b/src/basic/math/bafe.div10_FAC1_p.s
@@ -7,7 +7,7 @@
 ; Math package - divide FAC1 by 10, result is always positive
 ;
 ; Notes:
-; - shifts FAC1 to FAC2, loads FAC1 with the constant 10, falls through to the division routine
+; - moves FAC1 to FAC2, loads FAC1 with the constant 10, jumps to the division routine
 
 ;
 ; See also:
@@ -16,14 +16,11 @@
 ; - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
 ;
 
-; XXX test this
-
 div10_FAC1_p:
 
-	lda #$00
-	sta FAC1_sign
+    jsr mov_FAC1_FAC2
+    ldy #>const_TEN
+    lda #<const_TEN
+    jsr mov_MEM_FAC1
 
-	ldy #>const_TEN
-	lda #<const_TEN
-
-	jmp div_MEM_FAC1
+    jmp div_FAC2_FAC1
diff --git a/strings/842000000020 b/strings/842000000020
new file mode 100644
index 00000000..37486e9e
--- /dev/null
+++ b/strings/842000000020
@@ -0,0 +1 @@
+The floating point constant 10.0 + fragment
diff --git a/strings/A2BB4C12BB b/strings/A2BB4C12BB
new file mode 100644
index 00000000..3d9f1c19
--- /dev/null
+++ b/strings/A2BB4C12BB
@@ -0,0 +1,3 @@
+$BBA2 + JMP $BB12
+
+Fragment of well known floating point function address + JMP to other well known floating point function
diff --git a/strings/A84CA2B34C b/strings/A84CA2B34C
new file mode 100644
index 00000000..f1e07125
--- /dev/null
+++ b/strings/A84CA2B34C
@@ -0,0 +1,3 @@
+TAY + JMP $B3A2 + JMP fragment
+
+Fragments + jump to well known floating point function
diff --git a/testsuite/unit/math.vs b/testsuite/unit/math.vs
index d86a3330..f0399276 100644
--- a/testsuite/unit/math.vs
+++ b/testsuite/unit/math.vs
@@ -552,5 +552,112 @@ print "COMPARE"
 compare $61 $61 $1001
 print "END"
 
+print "TEST: div FAC2 FAC1 0.0 / 1.0 = 0.0"
+fill $61 $66 81 80 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 00 FF FF FF FF 00
+r PC=$BB12
+ret
+print "COMPARE"
+compare $61 $61 $69
+compare $70 $70 $6E  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 1.0 / 1.0 = 1.0"
+fill $61 $66 81 80 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 81 80 00 00 00 00
+r PC=$BB12
+ret
+fill $1001 $1006 81 80 00 00 00 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $6E  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 -1.0 / 1.0 = -1.0"
+fill $61 $66 81 80 00 00 00 80
+fill $70 $70 00
+fill $69 $6E 81 80 00 00 00 00
+r PC=$BB12
+ret
+fill $1001 $1006 81 80 00 00 00 80
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 1.0 / -1.0 = -1.0"
+fill $61 $66 81 80 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 81 80 00 00 00 80
+r PC=$BB12
+ret
+fill $1001 $1006 81 80 00 00 00 80
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 1.0 / 2.0 = 0.5"
+fill $61 $66 82 80 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 81 80 00 00 00 00
+r PC=$BB12
+ret
+fill $1001 $1006 80 80 00 00 00 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 2.0 / 0.5 = 4.0"
+fill $61 $66 80 80 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 82 80 00 00 00 00
+r PC=$BB12
+ret
+fill $1001 $1006 83 80 00 00 00 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 3.0 / 0.5 = 6.0"
+fill $61 $66 80 80 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 82 C0 00 00 00 00
+r PC=$BB12
+ret
+fill $1001 $1006 83 C0 00 00 00 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1003  ; FACOV = 0
+print "END"
+
+print "TEST: div FAC2 FAC1 1.0 / 10.0 = 0.1"
+fill $61 $66 84 A0 00 00 00 00
+fill $70 $70 00
+fill $69 $6E 81 80 00 00 00 00
+r PC=$BB12
+ret
+# Slight rounding error here. Should be CC at the end
+fill $1001 $1006 7D CC CC CC C8 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1006  ; FACOV = 0
+print "END"
+
+print "TEST: div10_FAC1 1.0 = 0.1"
+fill $61 $66 81 80 00 00 00 00
+fill $70 $70 00
+r PC=$BAFE
+ret
+# Slight rounding error here. Should be CC at the end
+fill $1001 $1007 7D CC CC CC C8 20 00
+print "COMPARE"
+compare $61 $66 $1001
+compare $70 $70 $1007  ; FACOV = 0
+print "END"
 
 q