From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Sat, 22 May 2021 11:35:11 +0000 (+1000)
Subject: fix * and amdd /MOD
X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=e41af95c9a45e52a18a363d173456870e505db5f;p=rrq%2Frrqforth.git

fix * and amdd /MOD
---

diff --git a/math.asm b/math.asm
index 5547b57..c678d11 100644
--- a/math.asm
+++ b/math.asm
@@ -16,26 +16,10 @@
 
 	WORD p_mult, '*',fasm
 	;; ( n1 n2 -- n3 )
-	;; Multiply n1 by n2 giving the product n3.
-	;; [rsp{8}] * [rsp+8{8}]
-	;; dd00 = [rsp+4{4}]*[rsp+12{4}] ignored
-	;; needs checking !!
-	;; 
-	;; 0cc0 = [rsp{4}]*[rsp+12{4}]
-	mov eax, dword [rsp]
-	imul dword [rsp+12]
-	mov ebx,eax
-	;; 0bb0 = [rsp+4{4}]*[rsp+8{4}]
-	mov eax, dword [rsp+4]
-	imul dword [rsp+8]
-	add ebx, eax
-	;; 00aa = [rsp{4}]*[rsp+8{4}]
-	mov eax, dword [rsp]
-	imul dword [rsp+8]
-	add ebx, edx
-	shl rbx,32
-	mov eax,eax		; ensure zero-extending eax
-	add rax, rbx
+	;; multiply n1 * n2 to n3 ignoring overflow
+	pop rax
+	pop rbx
+	imul rax,rbx
 	push rax
 	next
 
@@ -56,4 +40,14 @@ p_abs_end:
 	mov qword [rsp],rax
 	next
 
-	
+	WORD p_divmod,'/MOD',fasm
+	;; ( x y -- q r )
+	;; divide signed x/y giving quotient q and reminder r
+	pop rbx
+	pop rax
+	xor rdx,rdx
+	idiv rbx
+	push rax
+	push rdx
+	next
+