From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Thu, 17 Jun 2021 07:13:43 +0000 (+1000)
Subject: added max and min
X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=a625fdad0d2d7723188c78b761d7ea8294464017;p=rrq%2Frrqforth.git

added max and min
---

diff --git a/adoc/p_max.adoc b/adoc/p_max.adoc
new file mode 100644
index 0000000..b2ced15
--- /dev/null
+++ b/adoc/p_max.adoc
@@ -0,0 +1,12 @@
+// math.asm:	WORD p_max, 'MAX',fasm
+
+anchor:p_max[]
+
+=== Word: MAX
+
+....
+Data stack: ( v1 v2 -- v3 )
+....
+
+"MAX" is a function word that selects the greatest of v1 and v2. To
+that end, the values are 64-bit signed integers.
diff --git a/adoc/p_min.adoc b/adoc/p_min.adoc
new file mode 100644
index 0000000..b34ad96
--- /dev/null
+++ b/adoc/p_min.adoc
@@ -0,0 +1,12 @@
+// math.asm:	WORD p_min, 'MIN',fasm
+
+anchor:p_min[]
+
+=== Word: MIN
+
+....
+Data stack: ( v1 v2 -- v3 )
+....
+
+"MIN" is a function word that selects the least of v1 and v2. To that
+end, the values are 64-bit signed integers.
diff --git a/math.asm b/math.asm
index 3b82bd4..6248da9 100644
--- a/math.asm
+++ b/math.asm
@@ -32,6 +32,26 @@
 p_abs_end:
 	next
 
+	WORD p_max, 'MAX',fasm
+	;; ( a b -- c )
+	;; c is the least a and b
+	pop rax
+	cmp rax,qword [rsp]
+	jle p_max_end
+	mov qword [rsp],rax
+p_max_end:
+	next
+
+	WORD p_min, 'MIN',fasm
+	;; ( a b -- c )
+	;; c is the least a and b
+	pop rax
+	cmp rax,qword [rsp]
+	jge p_min_end
+	mov qword [rsp],rax
+p_min_end:
+	next
+
 	WORD p_negate, 'NEGATE',fasm
 	;; ( n1 -- n2 )
 	;; Negate n1, giving its arithmetic inverse n2. 
diff --git a/reference.adoc b/reference.adoc
index b9f9b29..1326440 100644
--- a/reference.adoc
+++ b/reference.adoc
@@ -201,6 +201,10 @@ include::adoc/p_lparen.adoc[]
 include::separator.adoc[]
 include::adoc/p_malloc.adoc[]
 include::separator.adoc[]
+include::adoc/p_max.adoc[]
+include::separator.adoc[]
+include::adoc/p_min.adoc[]
+include::separator.adoc[]
 include::adoc/p_minus.adoc[]
 include::separator.adoc[]
 include::adoc/p_mult.adoc[]
diff --git a/wordindex.adoc b/wordindex.adoc
index 7cecd32..6e54229 100644
--- a/wordindex.adoc
+++ b/wordindex.adoc
@@ -126,6 +126,8 @@ xref:p_load_file[LOAD-FILE] {nbsp}
 
 xref:p_args[MAIN-ARGS] {nbsp}
 xref:p_malloc[MALLOC] {nbsp}
+xref:p_min[MIN] {nbsp}
+xref:p_max[MAX] {nbsp}
 
 xref:p_negate[NEGATE] {nbsp}
 xref:p_nip[NIP] {nbsp}