From 6635346ae8479f933019bcef23fc6bead09fd1c1 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Sat, 6 Feb 2021 00:11:44 -0600
Subject: [PATCH] Implement llabs and imaxabs functions.

These give the absolute value of 64-bit numbers.
---
 stdlib.asm | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/stdlib.asm b/stdlib.asm
index af6d175..99d7669 100644
--- a/stdlib.asm
+++ b/stdlib.asm
@@ -496,6 +496,47 @@ labs     start
 lb1      creturn 4:i
          end
 
+****************************************************************
+*
+*  long long llabs(long long i)
+*
+*  Return the absolute value of i.
+*
+*  Inputs:
+*        i - argument
+*
+*  Outputs:
+*        Returns abs(i).
+*
+****************************************************************
+*
+llabs    start
+imaxabs  entry
+retptr   equ   1
+
+         csubroutine (8:i),4
+         stx   retptr
+         stz   retptr+2
+         
+         ph8   i
+         jsl   ~ABS8
+         pla
+         sta   [retptr]
+         ldy   #2
+         pla
+         sta   [retptr],y
+         iny
+         iny
+         pla
+         sta   [retptr],y
+         iny
+         iny
+         pla
+         sta   [retptr],y
+         
+         creturn
+         end
+
 ****************************************************************
 *
 *  ldiv_t ldiv(n,d)