1 files changed, 25 insertions, 0 deletions
diff --git a/x86_64/mul_by_add.s b/x86_64/mul_by_add.s
new file mode 100644
index 0000000..3e8c360
--- /dev/null
+++ b/x86_64/mul_by_add.s
@@ -0,0 +1,25 @@
+# Do a multiplication without using mulq, resulting in a * b
+.section .text
+.globl _start
+
+.set OP, 1	# Set here the numbers to
+.set OP2, 1	# be multiplied
+
+_start:
+	movq	$OP2, %rcx
+	movq	$0, %rax
+
+	# We can't rely on loopq to drop exit the loop in case OP2
+	# is 0, because the first iteraction will cause %rcx to be -1
+	cmpq	$OP2, %rax
+	je	exit
+
+
+addloop:
+	addq	$OP, %rax
+	loopq addloop
+
+exit:
+	movq	%rax, %rdi
+	movq	$60, %rax
+	syscall