From: Phil Dawes <phil@phildawes.net>
Date: Mon, 7 Sep 2009 17:20:43 +0000 (+0100)
Subject: imul clobbers arg2 on x86.64, so stashing vm ptr on the stack
X-Git-Tag: 0.97~5502^2~2^2~2
X-Git-Url: https://gitweb.factorcode.org/gitweb.cgi?p=factor.git;a=commitdiff_plain;h=8049b441c2ccdc1571ea7cbc134d3865c008816d

imul clobbers arg2 on x86.64, so stashing vm ptr on the stack
---

diff --git a/vm/cpu-x86.S b/vm/cpu-x86.S
index a18d1483fb..5360d6c227 100644
--- a/vm/cpu-x86.S
+++ b/vm/cpu-x86.S
@@ -21,7 +21,7 @@ DEF(void,primitive_fixnum_subtract,(void *myvm)):
 	ret
 
 DEF(void,primitive_fixnum_multiply,(void *myvm)):
-	mov ARG0, ARG2  /* save vm ptr for overflow */	
+	push ARG0  /* save vm ptr for overflow */
 	mov (DS_REG),ARITH_TEMP_1
 	mov ARITH_TEMP_1,DIV_RESULT
 	mov -CELL_SIZE(DS_REG),ARITH_TEMP_2
@@ -30,14 +30,16 @@ DEF(void,primitive_fixnum_multiply,(void *myvm)):
 	imul ARITH_TEMP_2
 	jo multiply_overflow
 	mov DIV_RESULT,(DS_REG)
+	pop ARG2
 	ret
-
 multiply_overflow:
 	sar $3,ARITH_TEMP_1
 	mov ARITH_TEMP_1,ARG0
 	mov ARITH_TEMP_2,ARG1
+	pop ARG2
 	jmp MANGLE(overflow_fixnum_multiply)
 
+
 DEF(F_FASTCALL void,c_to_factor,(CELL quot, void *vm)):
 	PUSH_NONVOLATILE
 	mov ARG0,NV_TEMP_REG