From 3b15df7f3040080e89e5aeda1a06d50a6ac5db27 Mon Sep 17 00:00:00 2001
From: d6 <d_m@plastic-idolatry.com>
Date: Tue, 28 Dec 2021 15:45:15 -0500
Subject: [PATCH] use stash with all left-shift methods

---
 math32.tal | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/math32.tal b/math32.tal
index 6682720..09a6367 100644
--- a/math32.tal
+++ b/math32.tal
@@ -181,30 +181,25 @@
 ( shift left by 8-15 bits )
 @left-shift1 ( x** n^ -> x<<n )
     #08 SUB #40 SFT STH ( stash [n-8]<<4 )
-
     #00 SWP STHkr SFT2                     ;sh/z1 STA2 ( store z1,z2 )
     #00 SWP STHkr SFT2 #00 ;sh/z1 LDA ORA2 ;sh/z0 STA2 ( store z0,z1 )
             STHr  SFT      ;sh/z0 LDA ORA              ( calculate z0 )
+    SWP POP ( x0 unused )
     ;sh/z1 LDA2 #00
     RTN
 
 ( shift left by 16-23 bits )
 @left-shift2 ( x** n^ -> x<<n )
-    #0000 ;sh/z0 STA2
-    #10 SUB #40 SFT STH ( n<<4 -> r )
-    SWP2 POP2 SWP ( x3 x2 )
-
-    STHkr SFT ;sh/z0 STA ( x3 )
-
-    #00 SWP STHr SFT2 ( x3<<r )
-    ;sh/z0 LDA2 ORA2 ;sh/z0 STA2 (  )
-
-    ;sh/z0 LDA2 #0000
+    #10 SUB #40 SFT STH ( stash [n-16]<<4 )
+    #00 SWP STHkr SFT2                ;sh/z0 STA2 ( store z0,z1 )
+            STHr  SFT  ;sh/z0 LDA ORA             ( calculate z0 )
+    STH POP2 STHr
+    ;sh/z1 LDA #0000
     RTN
 
 ( shift left by 24-31 bits )
 @left-shift3 ( x** n^ -> x<<n )
-    #18 SUB #10 MUL ( x0 x1 x2 x3 r=[n-24]<<4 )
+    #18 SUB #40 SFT ( x0 x1 x2 x3 r=[n-24]<<4 )
     SFT ( x0 x1 x2 x3<<r )
     SWP2 POP2 SWP POP #0000 #00
     RTN