From c6089808492748bcb322a48fe2d6574c6a2f0172 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Fri, 31 May 2024 16:13:57 +0530
Subject: [PATCH 1/8] Add feature and test: `alloc`, `load` and `store`
 instructions

---
 src/backend/brilisp.scm              | 23 ++++++++++++++++-----
 src/backend/llvm.py                  | 30 +++++++++++++++++++++++++---
 src/backend/tests/brilisp/alloc.out  |  1 +
 src/backend/tests/brilisp/alloc.sexp | 11 ++++++++++
 4 files changed, 57 insertions(+), 8 deletions(-)
 create mode 100644 src/backend/tests/brilisp/alloc.out
 create mode 100644 src/backend/tests/brilisp/alloc.sexp

diff --git a/src/backend/brilisp.scm b/src/backend/brilisp.scm
index 8bcb3cf..645c7ae 100644
--- a/src/backend/brilisp.scm
+++ b/src/backend/brilisp.scm
@@ -39,7 +39,12 @@
           (instrs . ,(map-vec gen-instr instrs)))))
 
 (define (gen-arg arg)
-    `((name . ,(first arg)) (type . ,(second arg))))
+    `((name . ,(first arg)) (type . ,(gen-type (second arg)))))
+
+(define (gen-type type)
+    (if (list? type)
+        `((,(first type) . ,(second type)))
+        type))
 
 (define (gen-instr instr)
     (define (const? instr)
@@ -50,20 +55,20 @@
         (let ((to (second instr))
               (from (third instr)))
             `((op . const)
-              (type . ,(second to))
+              (type . ,(gen-type (second to)))
               (dest . ,(first to))
               (value . ,(second from)))))
 
     (define (value? instr)
         (and (eq? (first instr) 'set)
              (memq (first (third instr))
-                '(add mul sub div eq lt gt le ge not and or))))
+                '(add mul sub div eq lt gt le ge not and or alloc load))))
 
     (define (gen-value-instr instr)
         (let ((to (second instr))
               (from (third instr)))
             `((op . ,(first from))
-              (type . ,(second to))
+              (type . ,(gen-type (second to)))
               (dest . ,(first to))
               (args . ,(list->vector (rest from))))))
 
@@ -81,7 +86,7 @@
         (let ((to (second instr))
               (from (third instr)))
             `((op . call)
-              (type . ,(second to))
+              (type . ,(gen-type (second to)))
               (dest . ,(first to))
               (funcs . ,(vector (second from)))
               (args . ,(list->vector (rest (rest from)))))))
@@ -113,6 +118,13 @@
     (define (gen-nop-instr instr)
         `((op . nop)))
 
+    (define (store? instr)
+        (eq? (first instr) 'store))
+
+    (define (gen-store-instr instr)
+        `((op . store)
+          (args . ,(list->vector (rest instr)))))
+
     (cond
         ((const? instr) (gen-const-instr instr))
         ((value? instr) (gen-value-instr instr))
@@ -122,6 +134,7 @@
         ((label? instr) (gen-label-instr instr))
         ((br? instr) (gen-br-instr instr))
         ((nop? instr) (gen-nop-instr instr))
+        ((store? instr) (gen-store-instr instr))
         (else (error "unknown instruction: " instr))))
 
 (bril (rest (read)))
diff --git a/src/backend/llvm.py b/src/backend/llvm.py
index cb94734..4e3cc83 100644
--- a/src/backend/llvm.py
+++ b/src/backend/llvm.py
@@ -4,8 +4,6 @@
 References:
 1. https://github.com/eliben/pykaleidoscope/
 2. https://llvm.org/docs/tutorial/
-
-Assumes BRIL is in SSA form
 """
 
 import sys
@@ -47,7 +45,12 @@ def generate(self, bril_prog):
             self.gen_function(fn)
 
     def gen_type(self, type):
-        if type == "int":
+        if isinstance (type, dict):
+            if 'ptr' in type:
+                return self.gen_type(type['ptr'])
+            else:
+                raise CodegenError (f"Unknown type {type}")
+        elif type == "int":
             return ir.IntType(32)
         elif type == "void":
             return ir.VoidType()
@@ -158,6 +161,21 @@ def gen_comp(instr):
                 ),
             )
 
+        def gen_alloc(instr):
+            pointee_type = self.gen_type(instr.type)
+            self.declare_var(pointee_type.as_pointer(), instr.dest)
+            self.gen_symbol_store(instr.dest, self.builder.alloca(pointee_type, size=self.gen_var(instr.args[0])))
+
+        def gen_store(instr):
+            ptr = self.gen_symbol_load(instr.args[0])
+            self.builder.store(self.gen_var(instr.args[1]), ptr)
+
+        def gen_load(instr):
+            self.declare_var(self.gen_type(instr.type), instr.dest)
+            ptr = self.gen_symbol_load(instr.args[0])
+            self.gen_symbol_store(
+                instr.dest, self.builder.load(ptr))
+
         for instr in instrs:
             if "label" in instr:
                 gen_label(instr)
@@ -175,6 +193,12 @@ def gen_comp(instr):
                 gen_ret(instr)
             elif instr.op == "const":
                 gen_const(instr)
+            elif instr.op == "alloc":
+                gen_alloc(instr)
+            elif instr.op == "store":
+                gen_store(instr)
+            elif instr.op == "load":
+                gen_load(instr)
             elif instr.op in value_ops:
                 gen_value(instr)
             elif instr.op in cmp_ops:
diff --git a/src/backend/tests/brilisp/alloc.out b/src/backend/tests/brilisp/alloc.out
new file mode 100644
index 0000000..00750ed
--- /dev/null
+++ b/src/backend/tests/brilisp/alloc.out
@@ -0,0 +1 @@
+3
diff --git a/src/backend/tests/brilisp/alloc.sexp b/src/backend/tests/brilisp/alloc.sexp
new file mode 100644
index 0000000..4aea578
--- /dev/null
+++ b/src/backend/tests/brilisp/alloc.sexp
@@ -0,0 +1,11 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main void))
+        (set (s int) (const 5))
+        (set (p1 (ptr int)) (alloc s))
+        (set (three int) (const 3))
+        (store p1 three)
+        (set (val int) (load p1))
+        (set (tmp int) (call print val))
+        (ret)))

From 7e638b609a24100c737c153fabb385fb677bc0d7 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Sat, 1 Jun 2024 20:36:42 +0530
Subject: [PATCH 2/8] Add test: `ptr_call`

---
 src/backend/llvm.py                     | 8 ++++----
 src/backend/tests/brilisp/ptr_call.out  | 0
 src/backend/tests/brilisp/ptr_call.sexp | 9 +++++++++
 3 files changed, 13 insertions(+), 4 deletions(-)
 create mode 100644 src/backend/tests/brilisp/ptr_call.out
 create mode 100644 src/backend/tests/brilisp/ptr_call.sexp

diff --git a/src/backend/llvm.py b/src/backend/llvm.py
index 4e3cc83..288d3eb 100644
--- a/src/backend/llvm.py
+++ b/src/backend/llvm.py
@@ -47,7 +47,7 @@ def generate(self, bril_prog):
     def gen_type(self, type):
         if isinstance (type, dict):
             if 'ptr' in type:
-                return self.gen_type(type['ptr'])
+                return self.gen_type(type['ptr']).as_pointer()
             else:
                 raise CodegenError (f"Unknown type {type}")
         elif type == "int":
@@ -162,9 +162,9 @@ def gen_comp(instr):
             )
 
         def gen_alloc(instr):
-            pointee_type = self.gen_type(instr.type)
-            self.declare_var(pointee_type.as_pointer(), instr.dest)
-            self.gen_symbol_store(instr.dest, self.builder.alloca(pointee_type, size=self.gen_var(instr.args[0])))
+            pointer_type = self.gen_type(instr.type)
+            self.declare_var(pointer_type, instr.dest)
+            self.gen_symbol_store(instr.dest, self.builder.alloca(pointer_type.pointee, size=self.gen_var(instr.args[0])))
 
         def gen_store(instr):
             ptr = self.gen_symbol_load(instr.args[0])
diff --git a/src/backend/tests/brilisp/ptr_call.out b/src/backend/tests/brilisp/ptr_call.out
new file mode 100644
index 0000000..e69de29
diff --git a/src/backend/tests/brilisp/ptr_call.sexp b/src/backend/tests/brilisp/ptr_call.sexp
new file mode 100644
index 0000000..5287ff6
--- /dev/null
+++ b/src/backend/tests/brilisp/ptr_call.sexp
@@ -0,0 +1,9 @@
+(brilisp
+    (bril-define ((funcA void) (p (ptr int)))
+        (ret))
+
+    (bril-define ((main void))
+        (set (five int) (const 5))
+        (set (x (ptr int)) (alloc five))
+        (set (tmp void) (call funcA x))
+        (ret)))

From 0a0a2c93a339fa5e8ca99ba407068d38905fd1b1 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Sat, 1 Jun 2024 20:51:38 +0530
Subject: [PATCH 3/8] Add test: `ptr_ret`

---
 src/backend/brilisp.scm                |  2 +-
 src/backend/llvm.py                    | 18 +++++++++++-------
 src/backend/tests/brilisp/ptr_ret.out  |  0
 src/backend/tests/brilisp/ptr_ret.sexp |  9 +++++++++
 4 files changed, 21 insertions(+), 8 deletions(-)
 create mode 100644 src/backend/tests/brilisp/ptr_ret.out
 create mode 100644 src/backend/tests/brilisp/ptr_ret.sexp

diff --git a/src/backend/brilisp.scm b/src/backend/brilisp.scm
index 645c7ae..59f4910 100644
--- a/src/backend/brilisp.scm
+++ b/src/backend/brilisp.scm
@@ -34,7 +34,7 @@
            (args (rest header))
            (instrs (rest (rest expr))))
         `((name . ,name)
-          (type . ,type)
+          (type . ,(gen-type type))
           (args . ,(map-vec gen-arg args))
           (instrs . ,(map-vec gen-instr instrs)))))
 
diff --git a/src/backend/llvm.py b/src/backend/llvm.py
index 288d3eb..af44b81 100644
--- a/src/backend/llvm.py
+++ b/src/backend/llvm.py
@@ -45,11 +45,11 @@ def generate(self, bril_prog):
             self.gen_function(fn)
 
     def gen_type(self, type):
-        if isinstance (type, dict):
-            if 'ptr' in type:
-                return self.gen_type(type['ptr']).as_pointer()
+        if isinstance(type, dict):
+            if "ptr" in type:
+                return self.gen_type(type["ptr"]).as_pointer()
             else:
-                raise CodegenError (f"Unknown type {type}")
+                raise CodegenError(f"Unknown type {type}")
         elif type == "int":
             return ir.IntType(32)
         elif type == "void":
@@ -164,7 +164,12 @@ def gen_comp(instr):
         def gen_alloc(instr):
             pointer_type = self.gen_type(instr.type)
             self.declare_var(pointer_type, instr.dest)
-            self.gen_symbol_store(instr.dest, self.builder.alloca(pointer_type.pointee, size=self.gen_var(instr.args[0])))
+            self.gen_symbol_store(
+                instr.dest,
+                self.builder.alloca(
+                    pointer_type.pointee, size=self.gen_var(instr.args[0])
+                ),
+            )
 
         def gen_store(instr):
             ptr = self.gen_symbol_load(instr.args[0])
@@ -173,8 +178,7 @@ def gen_store(instr):
         def gen_load(instr):
             self.declare_var(self.gen_type(instr.type), instr.dest)
             ptr = self.gen_symbol_load(instr.args[0])
-            self.gen_symbol_store(
-                instr.dest, self.builder.load(ptr))
+            self.gen_symbol_store(instr.dest, self.builder.load(ptr))
 
         for instr in instrs:
             if "label" in instr:
diff --git a/src/backend/tests/brilisp/ptr_ret.out b/src/backend/tests/brilisp/ptr_ret.out
new file mode 100644
index 0000000..e69de29
diff --git a/src/backend/tests/brilisp/ptr_ret.sexp b/src/backend/tests/brilisp/ptr_ret.sexp
new file mode 100644
index 0000000..acc00ea
--- /dev/null
+++ b/src/backend/tests/brilisp/ptr_ret.sexp
@@ -0,0 +1,9 @@
+(brilisp
+    (bril-define ((ident (ptr int)) (p (ptr int)))
+        (ret p))
+
+    (bril-define ((main void))
+        (set (a int) (const 9))
+        (set (b (ptr int)) (alloc a))
+        (set (c (ptr int)) (call ident b))
+        (ret)))

From 7aca6637b04cccc87fb9875f514a803ca8e51c51 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Sun, 2 Jun 2024 06:03:07 +0530
Subject: [PATCH 4/8] Add tests: `access`, `access_many`, and instruction:
 `ptradd`

---
 src/backend/brilisp.scm                    |  2 +-
 src/backend/llvm.py                        | 12 ++++++++++++
 src/backend/tests/brilisp/access.out       |  1 +
 src/backend/tests/brilisp/access.sexp      | 20 ++++++++++++++++++++
 src/backend/tests/brilisp/access_many.out  |  1 +
 src/backend/tests/brilisp/access_many.sexp | 21 +++++++++++++++++++++
 6 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 src/backend/tests/brilisp/access.out
 create mode 100644 src/backend/tests/brilisp/access.sexp
 create mode 100644 src/backend/tests/brilisp/access_many.out
 create mode 100644 src/backend/tests/brilisp/access_many.sexp

diff --git a/src/backend/brilisp.scm b/src/backend/brilisp.scm
index 59f4910..b0e45f3 100644
--- a/src/backend/brilisp.scm
+++ b/src/backend/brilisp.scm
@@ -62,7 +62,7 @@
     (define (value? instr)
         (and (eq? (first instr) 'set)
              (memq (first (third instr))
-                '(add mul sub div eq lt gt le ge not and or alloc load))))
+                '(add mul sub div eq lt gt le ge not and or alloc load ptradd))))
 
     (define (gen-value-instr instr)
         (let ((to (second instr))
diff --git a/src/backend/llvm.py b/src/backend/llvm.py
index af44b81..636e3df 100644
--- a/src/backend/llvm.py
+++ b/src/backend/llvm.py
@@ -180,6 +180,16 @@ def gen_load(instr):
             ptr = self.gen_symbol_load(instr.args[0])
             self.gen_symbol_store(instr.dest, self.builder.load(ptr))
 
+        def gen_ptradd(inst):
+            self.declare_var(self.gen_type(instr.type), instr.dest)
+            self.gen_symbol_store(
+                instr.dest,
+                self.builder.gep(
+                    self.gen_var(instr.args[0]),
+                    [self.gen_var(arg) for arg in instr["args"][1:]],
+                ),
+            )
+
         for instr in instrs:
             if "label" in instr:
                 gen_label(instr)
@@ -203,6 +213,8 @@ def gen_load(instr):
                 gen_store(instr)
             elif instr.op == "load":
                 gen_load(instr)
+            elif instr.op == "ptradd":
+                gen_ptradd(instr)
             elif instr.op in value_ops:
                 gen_value(instr)
             elif instr.op in cmp_ops:
diff --git a/src/backend/tests/brilisp/access.out b/src/backend/tests/brilisp/access.out
new file mode 100644
index 0000000..06e5182
--- /dev/null
+++ b/src/backend/tests/brilisp/access.out
@@ -0,0 +1 @@
+8989898
diff --git a/src/backend/tests/brilisp/access.sexp b/src/backend/tests/brilisp/access.sexp
new file mode 100644
index 0000000..eeed8ea
--- /dev/null
+++ b/src/backend/tests/brilisp/access.sexp
@@ -0,0 +1,20 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main void))
+        (set (inc int) (const 1))
+        (set (v int) (const 4545454))
+        (set (max int) (const 8989898))
+        (set (p (ptr int)) (alloc v))
+        (set (count int) (const 0))
+
+        (label lbl)
+        (set (count int) (add count inc))
+        (store p v)
+        (set (val int) (load p))
+        (set (loop bool) (ge count max))
+        (br loop end lbl)
+
+        (label end)
+        (set (tmp int) (call print count))
+        (ret)))
diff --git a/src/backend/tests/brilisp/access_many.out b/src/backend/tests/brilisp/access_many.out
new file mode 100644
index 0000000..06e5182
--- /dev/null
+++ b/src/backend/tests/brilisp/access_many.out
@@ -0,0 +1 @@
+8989898
diff --git a/src/backend/tests/brilisp/access_many.sexp b/src/backend/tests/brilisp/access_many.sexp
new file mode 100644
index 0000000..5ceb9e6
--- /dev/null
+++ b/src/backend/tests/brilisp/access_many.sexp
@@ -0,0 +1,21 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main void))
+        (set (inc int) (const 1))
+        (set (v int) (const 4545454))
+        (set (max int) (const 8989898))
+        (set (arr (ptr int)) (alloc v))
+        (set (count int) (const 0))
+
+        (label lbl)
+        (set (arr_i (ptr int)) (ptradd arr count))
+        (set (count int) (add count inc))
+        (store arr_i v)
+        (set (val int) (load arr_i))
+        (set (loop bool) (ge count max))
+        (br loop end lbl)
+
+        (label end)
+        (set (tmp int) (call print count))
+        (ret)))

From 27f5a2379e6f40a0957becf47ed7348adf51b694 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Mon, 3 Jun 2024 10:41:56 +0530
Subject: [PATCH 5/8] Add tests: `alloc`, `access_ptr`

Also fixed brilisp.scm to allow multi-dimensional pointers
---
 src/backend/brilisp.scm                    |  2 +-
 src/backend/tests/brilisp/access.sexp      |  4 +--
 src/backend/tests/brilisp/access_many.sexp |  4 +--
 src/backend/tests/brilisp/access_ptr.out   |  1 +
 src/backend/tests/brilisp/access_ptr.sexp  | 22 ++++++++++++++++
 src/backend/tests/brilisp/alloc.out        |  2 +-
 src/backend/tests/brilisp/alloc.sexp       | 30 ++++++++++++++++------
 7 files changed, 51 insertions(+), 14 deletions(-)
 create mode 100644 src/backend/tests/brilisp/access_ptr.out
 create mode 100644 src/backend/tests/brilisp/access_ptr.sexp

diff --git a/src/backend/brilisp.scm b/src/backend/brilisp.scm
index b0e45f3..a564868 100644
--- a/src/backend/brilisp.scm
+++ b/src/backend/brilisp.scm
@@ -43,7 +43,7 @@
 
 (define (gen-type type)
     (if (list? type)
-        `((,(first type) . ,(second type)))
+        `((,(first type) . ,(gen-type (second type))))
         type))
 
 (define (gen-instr instr)
diff --git a/src/backend/tests/brilisp/access.sexp b/src/backend/tests/brilisp/access.sexp
index eeed8ea..e003131 100644
--- a/src/backend/tests/brilisp/access.sexp
+++ b/src/backend/tests/brilisp/access.sexp
@@ -1,7 +1,7 @@
 (brilisp
     (bril-define ((print int) (n int)))
 
-    (bril-define ((main void))
+    (bril-define ((main int))
         (set (inc int) (const 1))
         (set (v int) (const 4545454))
         (set (max int) (const 8989898))
@@ -17,4 +17,4 @@
 
         (label end)
         (set (tmp int) (call print count))
-        (ret)))
+        (ret tmp)))
diff --git a/src/backend/tests/brilisp/access_many.sexp b/src/backend/tests/brilisp/access_many.sexp
index 5ceb9e6..0527599 100644
--- a/src/backend/tests/brilisp/access_many.sexp
+++ b/src/backend/tests/brilisp/access_many.sexp
@@ -1,7 +1,7 @@
 (brilisp
     (bril-define ((print int) (n int)))
 
-    (bril-define ((main void))
+    (bril-define ((main int))
         (set (inc int) (const 1))
         (set (v int) (const 4545454))
         (set (max int) (const 8989898))
@@ -18,4 +18,4 @@
 
         (label end)
         (set (tmp int) (call print count))
-        (ret)))
+        (ret tmp)))
diff --git a/src/backend/tests/brilisp/access_ptr.out b/src/backend/tests/brilisp/access_ptr.out
new file mode 100644
index 0000000..06e5182
--- /dev/null
+++ b/src/backend/tests/brilisp/access_ptr.out
@@ -0,0 +1 @@
+8989898
diff --git a/src/backend/tests/brilisp/access_ptr.sexp b/src/backend/tests/brilisp/access_ptr.sexp
new file mode 100644
index 0000000..89d3528
--- /dev/null
+++ b/src/backend/tests/brilisp/access_ptr.sexp
@@ -0,0 +1,22 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main int))
+        (set (inc int) (const 1))
+        (set (v int) (const 4545))
+        (set (max int) (const 8989898))
+        (set (p (ptr int)) (alloc v))
+        (set (arr (ptr (ptr int))) (alloc v))
+        (set (count int) (const 0))
+
+        (label lbl)
+        (set (arr_i (ptr (ptr int))) (ptradd arr count))
+        (set (count int) (add count inc))
+        (store arr p)
+        (set (val (ptr int)) (load arr_i))
+        (set (loop bool) (ge count max))
+        (br loop end lbl)
+
+        (label end)
+        (set (tmp int) (call print count))
+        (ret tmp)))
diff --git a/src/backend/tests/brilisp/alloc.out b/src/backend/tests/brilisp/alloc.out
index 00750ed..d00491f 100644
--- a/src/backend/tests/brilisp/alloc.out
+++ b/src/backend/tests/brilisp/alloc.out
@@ -1 +1 @@
-3
+1
diff --git a/src/backend/tests/brilisp/alloc.sexp b/src/backend/tests/brilisp/alloc.sexp
index 4aea578..519f349 100644
--- a/src/backend/tests/brilisp/alloc.sexp
+++ b/src/backend/tests/brilisp/alloc.sexp
@@ -1,11 +1,25 @@
 (brilisp
     (bril-define ((print int) (n int)))
 
-    (bril-define ((main void))
-        (set (s int) (const 5))
-        (set (p1 (ptr int)) (alloc s))
-        (set (three int) (const 3))
-        (store p1 three)
-        (set (val int) (load p1))
-        (set (tmp int) (call print val))
-        (ret)))
+    (bril-define ((print_bool int) (b bool))
+        (set (T int) (const 1))
+        (set (F int) (const 0))
+        (br b print_true print_false)
+        (label print_true)
+        (set (tmp int) (call print T))
+        (ret tmp)
+        (label print_false)
+        (set (tmp int) (call print F))
+        (ret tmp))
+
+    (bril-define ((main int))
+        (set (v int) (const 4))
+        (set (o1 int) (const 1))
+        (set (bp (ptr bool)) (alloc v))
+        (set (bp2 (ptr bool)) (ptradd bp o1))
+        (set (b bool) (const true))
+        (store bp b)
+        (store bp2 b)
+        (set (b bool) (load bp2))
+        (set (tmp int) (call print_bool b))
+        (ret tmp)))

From ae7c487d7a5ad012b6b84e0e7122fc684772ce43 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Mon, 3 Jun 2024 11:59:56 +0530
Subject: [PATCH 6/8] Add test: `fib`

It works!!
---
 src/backend/tests/brilisp/fib.out  |  1 +
 src/backend/tests/brilisp/fib.sexp | 37 ++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 src/backend/tests/brilisp/fib.out
 create mode 100644 src/backend/tests/brilisp/fib.sexp

diff --git a/src/backend/tests/brilisp/fib.out b/src/backend/tests/brilisp/fib.out
new file mode 100644
index 0000000..a787364
--- /dev/null
+++ b/src/backend/tests/brilisp/fib.out
@@ -0,0 +1 @@
+34
diff --git a/src/backend/tests/brilisp/fib.sexp b/src/backend/tests/brilisp/fib.sexp
new file mode 100644
index 0000000..f71334c
--- /dev/null
+++ b/src/backend/tests/brilisp/fib.sexp
@@ -0,0 +1,37 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main int))
+        (set (one int) (const 1))
+        (set (i int) (const 2))
+        (set (i_m_1 int) (const 1))
+        (set (i_m_2 int) (const 0))
+        (set (n int) (const 10))
+        (set (seq (ptr int)) (alloc n))
+
+        (set (v int) (const 0))
+        (store seq v)
+        (set (v int) (const 1))
+        (set (p (ptr int)) (ptradd seq i_m_1))
+        (store p v)
+
+        (label calc_i)
+        (set (p_m_2 (ptr int)) (ptradd seq i_m_2))
+        (set (p_m_1 (ptr int)) (ptradd seq i_m_1))
+        (set (v_m_2 int) (load p_m_2))
+        (set (v_m_1 int) (load p_m_1))
+        (set (v int) (add v_m_1 v_m_2))
+        (set (p (ptr int)) (ptradd seq i))
+        (store p v)
+        (set (i_m_1 int) (add i_m_1 one))
+        (set (i_m_2 int) (add i_m_2 one))
+        (set (i int) (add i one))
+        (set (loop bool) (le i n))
+        (br loop calc_i out)
+
+        (label out)
+        (set (i int) (sub n one))
+        (set (p (ptr int)) (ptradd seq i))
+        (set (v int) (load p))
+        (set (tmp int) (call print v))
+        (ret tmp)))

From 70315a7c1a0dd13bdd640dafe747c44e6f760d78 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Mon, 3 Jun 2024 12:52:54 +0530
Subject: [PATCH 7/8] Add test: `mem_id` and instruction: `id`

---
 src/backend/brilisp.scm               |  2 +-
 src/backend/llvm.py                   | 72 +++++++++++++++------------
 src/backend/tests/brilisp/mem_id.out  |  1 +
 src/backend/tests/brilisp/mem_id.sexp | 13 +++++
 4 files changed, 56 insertions(+), 32 deletions(-)
 create mode 100644 src/backend/tests/brilisp/mem_id.out
 create mode 100644 src/backend/tests/brilisp/mem_id.sexp

diff --git a/src/backend/brilisp.scm b/src/backend/brilisp.scm
index a564868..da1f9bb 100644
--- a/src/backend/brilisp.scm
+++ b/src/backend/brilisp.scm
@@ -62,7 +62,7 @@
     (define (value? instr)
         (and (eq? (first instr) 'set)
              (memq (first (third instr))
-                '(add mul sub div eq lt gt le ge not and or alloc load ptradd))))
+                '(add mul sub div eq lt gt le ge not and or alloc load ptradd id))))
 
     (define (gen-value-instr instr)
         (let ((to (second instr))
diff --git a/src/backend/llvm.py b/src/backend/llvm.py
index 636e3df..5b73357 100644
--- a/src/backend/llvm.py
+++ b/src/backend/llvm.py
@@ -180,7 +180,7 @@ def gen_load(instr):
             ptr = self.gen_symbol_load(instr.args[0])
             self.gen_symbol_store(instr.dest, self.builder.load(ptr))
 
-        def gen_ptradd(inst):
+        def gen_ptradd(instr):
             self.declare_var(self.gen_type(instr.type), instr.dest)
             self.gen_symbol_store(
                 instr.dest,
@@ -190,37 +190,47 @@ def gen_ptradd(inst):
                 ),
             )
 
+        def gen_id(instr):
+            self.declare_var(self.gen_type(instr.type), instr.dest)
+            self.gen_symbol_store(instr.dest, self.gen_symbol_load(instr.args[0]))
+
         for instr in instrs:
-            if "label" in instr:
-                gen_label(instr)
-            elif self.builder.block.is_terminated:
-                pass  # Do not codegen for unreachable code
-            elif instr.op == "nop":
-                pass
-            elif instr.op == "jmp":
-                gen_jmp(instr)
-            elif instr.op == "br":
-                gen_br(instr)
-            elif instr.op == "call":
-                gen_call(instr)
-            elif instr.op == "ret":
-                gen_ret(instr)
-            elif instr.op == "const":
-                gen_const(instr)
-            elif instr.op == "alloc":
-                gen_alloc(instr)
-            elif instr.op == "store":
-                gen_store(instr)
-            elif instr.op == "load":
-                gen_load(instr)
-            elif instr.op == "ptradd":
-                gen_ptradd(instr)
-            elif instr.op in value_ops:
-                gen_value(instr)
-            elif instr.op in cmp_ops:
-                gen_comp(instr)
-            else:
-                raise CodegenError(f"Unknown op in the instruction: {dict(instr)}")
+            try:
+                if "label" in instr:
+                    gen_label(instr)
+                elif self.builder.block.is_terminated:
+                    pass  # Do not codegen for unreachable code
+                elif instr.op == "nop":
+                    pass
+                elif instr.op == "jmp":
+                    gen_jmp(instr)
+                elif instr.op == "br":
+                    gen_br(instr)
+                elif instr.op == "call":
+                    gen_call(instr)
+                elif instr.op == "ret":
+                    gen_ret(instr)
+                elif instr.op == "const":
+                    gen_const(instr)
+                elif instr.op == "alloc":
+                    gen_alloc(instr)
+                elif instr.op == "store":
+                    gen_store(instr)
+                elif instr.op == "load":
+                    gen_load(instr)
+                elif instr.op == "ptradd":
+                    gen_ptradd(instr)
+                elif instr.op == "id":
+                    gen_id(instr)
+                elif instr.op in value_ops:
+                    gen_value(instr)
+                elif instr.op in cmp_ops:
+                    gen_comp(instr)
+                else:
+                    raise CodegenError(f"Unknown op in the instruction: {dict(instr)}")
+            except Exception as e:
+                print(f"Exception: {e}; in instruction {instr}:")
+                raise e
 
     def gen_function_prototype(self, fn):
         funcname = fn.name
diff --git a/src/backend/tests/brilisp/mem_id.out b/src/backend/tests/brilisp/mem_id.out
new file mode 100644
index 0000000..7f8f011
--- /dev/null
+++ b/src/backend/tests/brilisp/mem_id.out
@@ -0,0 +1 @@
+7
diff --git a/src/backend/tests/brilisp/mem_id.sexp b/src/backend/tests/brilisp/mem_id.sexp
new file mode 100644
index 0000000..8006aad
--- /dev/null
+++ b/src/backend/tests/brilisp/mem_id.sexp
@@ -0,0 +1,13 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main int))
+        (set (v int) (const 1))
+        (set (p (ptr int)) (alloc v))
+        (set (v int) (const 7))
+        (store p v)
+
+        (set (p2 (ptr int)) (id p))
+        (set (v int) (load p))
+        (set (tmp int) (call print v))
+        (ret tmp)))

From f43772629c18dacfef8ac5d574744f0c82ef5001 Mon Sep 17 00:00:00 2001
From: Vedanth Padmaraman <vedanthpadmaraman0566@gmail.com>
Date: Mon, 3 Jun 2024 16:04:36 +0530
Subject: [PATCH 8/8] Add tests: `arr_sum` and `transpose`

---
 src/backend/tests/brilisp/arr_sum.out    |  1 +
 src/backend/tests/brilisp/arr_sum.sexp   | 28 ++++++++
 src/backend/tests/brilisp/transpose.out  |  9 +++
 src/backend/tests/brilisp/transpose.sexp | 85 ++++++++++++++++++++++++
 4 files changed, 123 insertions(+)
 create mode 100644 src/backend/tests/brilisp/arr_sum.out
 create mode 100644 src/backend/tests/brilisp/arr_sum.sexp
 create mode 100644 src/backend/tests/brilisp/transpose.out
 create mode 100644 src/backend/tests/brilisp/transpose.sexp

diff --git a/src/backend/tests/brilisp/arr_sum.out b/src/backend/tests/brilisp/arr_sum.out
new file mode 100644
index 0000000..c3f407c
--- /dev/null
+++ b/src/backend/tests/brilisp/arr_sum.out
@@ -0,0 +1 @@
+55
diff --git a/src/backend/tests/brilisp/arr_sum.sexp b/src/backend/tests/brilisp/arr_sum.sexp
new file mode 100644
index 0000000..3271eb4
--- /dev/null
+++ b/src/backend/tests/brilisp/arr_sum.sexp
@@ -0,0 +1,28 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((main int))
+        (set (len int) (const 10))
+        (set (arr (ptr int)) (alloc len))
+        (set (sum int) (const 0))
+        (set (idx int) (const 0))
+        (set (one int) (const 1))
+
+        (label init)
+        (set (arr_i (ptr int)) (ptradd arr idx))
+        (set (idx int) (add idx one))
+        (store arr_i idx)
+        (set (loop bool) (lt idx len))
+        (br loop init calc)
+
+        (label calc)
+        (set (idx int) (sub idx one))
+        (set (arr_i (ptr int)) (ptradd arr idx))
+        (set (v int) (load arr_i))
+        (set (sum int) (add sum v))
+        (set (loop bool) (ge idx one))
+        (br loop calc out)
+
+        (label out)
+        (set (tmp int) (call print sum))
+        (ret tmp)))
diff --git a/src/backend/tests/brilisp/transpose.out b/src/backend/tests/brilisp/transpose.out
new file mode 100644
index 0000000..7d5c1b4
--- /dev/null
+++ b/src/backend/tests/brilisp/transpose.out
@@ -0,0 +1,9 @@
+0
+1
+2
+2
+3
+4
+4
+5
+6
diff --git a/src/backend/tests/brilisp/transpose.sexp b/src/backend/tests/brilisp/transpose.sexp
new file mode 100644
index 0000000..fc910d9
--- /dev/null
+++ b/src/backend/tests/brilisp/transpose.sexp
@@ -0,0 +1,85 @@
+(brilisp
+    (bril-define ((print int) (n int)))
+
+    (bril-define ((elem int) (i int) (j int))
+        (set (two int) (const 2))
+        (set (j int) (mul j two))
+        (set (i int) (add i j))
+        (ret i))
+
+    (bril-define ((arr_read int) (arr (ptr (ptr int))) (i int) (j int))
+        (set (p (ptr (ptr int))) (ptradd arr i))
+        (set (r (ptr int)) (load p))
+        (set (p (ptr int)) (ptradd r j))
+        (set (v int) (load p))
+        (ret v))
+
+    (bril-define ((arr_write void) (arr (ptr (ptr int))) (i int) (j int) (v int))
+        (set (p (ptr (ptr int))) (ptradd arr i))
+        (set (r (ptr int)) (load p))
+        (set (p (ptr int)) (ptradd r j))
+        (store p v)
+        (ret))
+
+    (bril-define ((main void))
+        (set (one int) (const 1))
+        (set (three int) (const 3))
+        (set (arr (ptr (ptr int))) (alloc three))
+        (set (i int) (const 0))
+        (set (j int) (const 0))
+
+        (label init_row)
+        (set (p (ptr (ptr int))) (ptradd arr i))
+        (set (r (ptr int)) (alloc three))
+        (store p r)
+        (label init_col)
+        (set (v int) (call elem i j))
+        (set (tmp void) (call arr_write arr i j v))
+        (set (j int) (add j one))
+        (set (j_loop bool) (lt j three))
+        (br j_loop init_col cont1)
+        (label cont1)
+        (set (j int) (const 0))
+        (set (i int) (add i one))
+        (set (i_loop bool) (lt i three))
+        (br i_loop init_row cont2)
+
+        (label cont2)
+        (set (i int) (const 0))
+        (set (j int) (const 0))
+
+        (label calc_row)
+        (set (j int) (add i one))
+        (label calc_col)
+        (set (vij int) (call arr_read arr i j))
+        (set (vji int) (call arr_read arr j i))
+        (set (tmp void) (call arr_write arr i j vji))
+        (set (tmp void) (call arr_write arr j i vij))
+        (set (j int) (add j one))
+        (set (j_loop bool) (le j three))
+        (br j_loop calc_col cont3)
+        (label cont3)
+        (set (j int) (const 0))
+        (set (i int) (add i one))
+        (set (i_loop bool) (le i three))
+        (br i_loop calc_row cont4)
+
+        (label cont4)
+        (set (i int) (const 0))
+        (set (j int) (const 0))
+
+        (label out_row)
+        (label out_col)
+        (set (v int) (call arr_read arr i j))
+        (set (tmp int) (call print v))
+        (set (j int) (add j one))
+        (set (j_loop bool) (lt j three))
+        (br j_loop out_col cont5)
+        (label cont5)
+        (set (j int) (const 0))
+        (set (i int) (add i one))
+        (set (i_loop bool) (lt i three))
+        (br i_loop out_row cont6)
+
+        (label cont6)
+        (ret)))