From 78cb6a5dd59a0106298ab1d88767ef97ae254f45 Mon Sep 17 00:00:00 2001
From: d_m <d_m@plastic-idolatry.com>
Date: Thu, 9 Nov 2023 22:08:42 -0500
Subject: [PATCH] comparisons for bc15 numbers

---
 src/bcb.c | 14 ++++++++++++++
 src/bcb.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/src/bcb.c b/src/bcb.c
index ee84398..fdb8ecd 100644
--- a/src/bcb.c
+++ b/src/bcb.c
@@ -226,6 +226,20 @@ bc15carry(int next, int *digit, int *carry)
 	}
 }
 
+bc3
+bc15cmp(bc15 a, bc15 b)
+{
+	int i;
+	for(i = 28; i >= 0; i -= 2) {
+		/* altered repr: 0 (-) 1 (zero) 2 (+) */
+		bc3 x = ((a >> i) + 1) & 0x3;
+		bc3 y = ((b >> i) + 1) & 0x3;
+		if (x != y)
+			return x < y ? 3 : 1;
+	}
+	return 0;
+}
+
 // Unsigned(TODO: migrate to 11-00-01 encoding)
 
 int
diff --git a/src/bcb.h b/src/bcb.h
index fea1b32..46c4555 100644
--- a/src/bcb.h
+++ b/src/bcb.h
@@ -53,6 +53,7 @@ bc15 bc15tnor(bc15 a);
 bc15 bc15negate(bc15 a);
 bc15 bc15add(bc15 a, bc15 b);
 void bc15carry(int sum, int *digit, int *carry);
+bc15 bc15cmp(bc15 a, bc15 b);
 
 // Unsigned
 int uc15int(uc15 t);
-- 
2.45.2