From bbde9e43c3503e6d4ae2e180a6ac01305744ae68 Mon Sep 17 00:00:00 2001
From: Aymen Dirar
Date: Sun, 23 Oct 2022 16:01:40 -0700
Subject: rename to `.s`

---
 entries/adirar111/y86/fib.s | 56 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 entries/adirar111/y86/fib.s

(limited to 'entries/adirar111/y86/fib.s')

diff --git a/entries/adirar111/y86/fib.s b/entries/adirar111/y86/fib.s
new file mode 100644
index 0000000..156c1ae
--- /dev/null
+++ b/entries/adirar111/y86/fib.s
@@ -0,0 +1,56 @@
+# y86 implementation of
+# def fibonacci(n):
+# if n <= 1:
+# return n
+# return fibonacci(n-1) + fibonacci(n-2)
+
+.pos 0
+main:
+irmovq stack, %rsp # initialize stack pointer
+irmovq $13, %rdi # %rdi = n
+call fib # fib(n)
+halt
+
+
+fib:
+irmovq $2, %rsi
+irmovq $1, %rdx
+rrmovq %rdi, %rcx
+rrmovq %rdi, %r8
+
+subq %rsi, %rcx # %rcx = n-2
+subq %rdx, %r8 # %r8 = n-1
+jle base # goto base if n <= 1
+
+recursed:
+# save to stack
+pushq %r8 # %r8 = n-1
+
+# recurse
+rrmovq %rcx, %rdi # %rdi = n-2
+call fib # fib(n-2)
+
+# restore from stack
+popq %r8 # %r8 = n-1
+
+# save to stack
+pushq %rax # %rax = fib(n-2)
+
+# recurse
+rrmovq %r8, %rdi # %rdi = n-1
+call fib # fib(n-1)
+
+# restore from stack
+popq %r10 # r10 = fib(n-2)
+
+addq %r10, %rax # %rax = fib(n-2) + fib(n-1)
+jmp end
+
+base:
+rrmovq %rdi, %rax # return n
+
+end:
+ret
+
+.pos 0x1000
+stack:
-- 
cgit v1.2.3-70-g09d2


From bdd284352a0cff33cff2fdc88b154301b63b2306 Mon Sep 17 00:00:00 2001
From: Aymen Dirar
Date: Sun, 23 Oct 2022 16:04:16 -0700
Subject: links to try

---
 entries/adirar111/y86/fib.s | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'entries/adirar111/y86/fib.s')

diff --git a/entries/adirar111/y86/fib.s b/entries/adirar111/y86/fib.s
index 156c1ae..eae74fe 100644
--- a/entries/adirar111/y86/fib.s
+++ b/entries/adirar111/y86/fib.s
@@ -3,6 +3,9 @@
 # if n <= 1:
 # return n
 # return fibonacci(n-1) + fibonacci(n-2)
+# run it:
+#  * https://www.students.cs.ubc.ca/~cs-313/simulator/?arch=y86&impl=seq
+#  * https://www.eecs.yorku.ca/~jonatan/simulator/?arch=y86&impl=seq
 
 .pos 0
 main:
-- 
cgit v1.2.3-70-g09d2


From 7e1694ced1cfce43f79cb4641781d91ebcc15e90 Mon Sep 17 00:00:00 2001
From: Aymen Dirar
Date: Sun, 23 Oct 2022 16:07:58 -0700
Subject: indent comment

---
 entries/adirar111/y86/fib.s | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'entries/adirar111/y86/fib.s')

diff --git a/entries/adirar111/y86/fib.s b/entries/adirar111/y86/fib.s
index eae74fe..8aa62d2 100644
--- a/entries/adirar111/y86/fib.s
+++ b/entries/adirar111/y86/fib.s
@@ -1,8 +1,10 @@
 # y86 implementation of
+#
 # def fibonacci(n):
-# if n <= 1:
-# return n
-# return fibonacci(n-1) + fibonacci(n-2)
+#     if n <= 1:
+#         return n
+#     return fibonacci(n-1) + fibonacci(n-2)
+#
 # run it:
 #  * https://www.students.cs.ubc.ca/~cs-313/simulator/?arch=y86&impl=seq
 #  * https://www.eecs.yorku.ca/~jonatan/simulator/?arch=y86&impl=seq
-- 
cgit v1.2.3-70-g09d2