From 2392745f6fc294679c04c2f3c52828c001c1f702 Mon Sep 17 00:00:00 2001
From: d_m <d_m@plastic-idolatry.com>
Date: Sun, 5 Nov 2023 21:06:22 -0500
Subject: [PATCH] better bug fix

---
 fix16.tal     | 14 +++++++++-----
 test-fix16.py |  7 +++++--
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/fix16.tal b/fix16.tal
index 64ad2d2..c7be7b2 100644
--- a/fix16.tal
+++ b/fix16.tal
@@ -342,17 +342,21 @@
     &done                       ( x* s1* [c* 2*] )
         POP2r POP2r NIP2 JMP2r  ( s1* )
 
+@x16-unit-circle ( x* -> x'* )
+    x16-pi*2 STH2            ( x       [2pi] )
+    DUP2 STH2kr x16-quotient ( x x/2pi [2pi] )
+    DUP2 #1400 DIV2 STH2 SWP2r ( x x/2pi [adj* 2pi*] )
+    STH2r x16-mul STH2r ADD2 SUB2       ( x' ; 0 <= x' < 2pi )
+    JMP2r
+
 @x16-cos ( x* -> cos[x]* )
-    x16-pi/2 ADD2
+    x16-unit-circle x16-pi/2 ADD2 ( fall-through )
 
 @x16-sin ( x* -> sin[x]* )
     DUP2 #8000 LTH2 ?&non-negative
     x16-negate x16-sin/non-negative !x16-negate
     &non-negative
-    x16-pi*2 STH2            ( x       [2pi] )
-    DUP2 STH2kr x16-quotient ( x x/2pi [2pi] )
-    DUP2 #1400 DIV2 STH2 SWP2r ( x x/2pi [adj* 2pi*] )
-    STH2r x16-mul STH2r ADD2 SUB2       ( x' ; 0 <= x' < 2pi )
+        x16-unit-circle
         DUP2 x16-3pi/2 LTH2 ?&c1
     ( -sin(2pi - x) ) x16-pi*2 SWP2 SUB2 x16-sin-q !x16-negate
     &c1 DUP2 x16-pi LTH2 ?&c2
diff --git a/test-fix16.py b/test-fix16.py
index b168f06..a8015fa 100644
--- a/test-fix16.py
+++ b/test-fix16.py
@@ -4,7 +4,7 @@ from math import ceil, copysign, cos, floor, log, sin, sqrt, tan
 from os import environ
 from random import randint
 from subprocess import Popen, PIPE, run
-from sys import argv
+from sys import argv, exit
 
 def tosigned(x):
     return x if x < 32768 else x - 65536
@@ -173,7 +173,10 @@ def x16_trunc8(x):
 
 def main():
     trials = int(argv[1]) if argv[1:] else 100
-    run(['uxnasm', 'test-fix16.tal', 'run.rom'])
+    e = run(['uxnasm', 'test-fix16.tal', 'run.rom'])
+    if e.returncode != 0:
+        print('the command `uxnasm test-fix16.tal run.rom` failed!')
+        exit(e.returncode)
     p = pipe()
     test(p, trials, b'+', [('x', u16), ('y', u16)], u16, x16_add)
     test(p, trials, b'-', [('x', u16), ('y', u16)], u16, x16_sub)