From a28f735b713c7c94f1b2f5dcc7c800041614be1b Mon Sep 17 00:00:00 2001
From: Siddharth Bhat <siddu.druid@gmail.com>
Date: Thu, 15 Jun 2017 23:04:46 +0200
Subject: [PATCH] extract prelude.ll. Will need to read this file and then add
 its contents into the module somehow

---
 prelude.ll              | 134 ++++++++++++++++++++++++++++++++++++++++
 src/llvm_interpreter.rs |   2 -
 2 files changed, 134 insertions(+), 2 deletions(-)
 create mode 100644 prelude.ll

diff --git a/prelude.ll b/prelude.ll
new file mode 100644
index 0000000..465e97d
--- /dev/null
+++ b/prelude.ll
@@ -0,0 +1,134 @@
+; LLVM prelude that is linked against when building the module
+@balloon_int = constant i32 0
+@balloon_float = constant i32 1
+@balloon_boolean = constant i32 2
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.memset.p0i8.i32(i8* nocapture writeonly, i8, i32, i32, i1) #0
+
+declare i8* @malloc(i32)
+
+declare void @free(i8*)
+
+declare i32 @write(i32, i8*, i32)
+
+declare i32 @putchar(i32)
+
+declare i32 @getchar()
+
+define { i32, i64 }* @box_balloon_int(i64 %input) {
+entry:
+  %mallocmem = call i8* @malloc(i32 ptrtoint ({ i32, i64 }* getelementptr ({ i32, i64 }, { i32, i64 }* null, i32 1) to i32))
+  %box = bitcast i8* %mallocmem to { i32, i64 }*
+  %slotp = getelementptr inbounds { i32, i64 }, { i32, i64 }* %box, i32 0, i32 1
+  store i64 %input, i64* %slotp
+  %tagval = load i32, i32* @balloon_int
+  %box_tag = getelementptr inbounds { i32, i64 }, { i32, i64 }* %box, i32 0, i32 0
+  store i32 %tagval, i32* %box_tag
+  ret { i32, i64 }* %box
+}
+
+define i64 @unbox_balloon_int({ i32, i64 }* %boxp) {
+entry:
+  %slotp = getelementptr inbounds { i32, i64 }, { i32, i64 }* %boxp, i32 0, i32 1
+  %rawval = load i64, i64* %slotp
+  ret i64 %rawval
+}
+
+define { i32, i64 }* @box_balloon_float(double %input) {
+entry:
+  %f64_to_i64 = bitcast double %input to i64
+  %mallocmem = call i8* @malloc(i32 ptrtoint ({ i32, i64 }* getelementptr ({ i32, i64 }, { i32, i64 }* null, i32 1) to i32))
+  %box = bitcast i8* %mallocmem to { i32, i64 }*
+  %slotp = getelementptr inbounds { i32, i64 }, { i32, i64 }* %box, i32 0, i32 1
+  store i64 %f64_to_i64, i64* %slotp
+  %tagval = load i32, i32* @balloon_float
+  %box_tag = getelementptr inbounds { i32, i64 }, { i32, i64 }* %box, i32 0, i32 0
+  store i32 %tagval, i32* %box_tag
+  ret { i32, i64 }* %box
+}
+
+define double @unbox_balloon_float({ i32, i64 }* %boxp) {
+entry:
+  %slotp = getelementptr inbounds { i32, i64 }, { i32, i64 }* %boxp, i32 0, i32 1
+  %rawval = load i64, i64* %slotp
+  %i64_to_f64 = bitcast i64 %rawval to double
+  ret double %i64_to_f64
+}
+
+define i32 @unbox_tag({ i32, i64 }* %boxp) {
+entry:
+  %tagp = getelementptr inbounds { i32, i64 }, { i32, i64 }* %boxp, i32 0, i32 0
+  %tag = load i32, i32* %tagp
+  ret i32 %tag
+}
+
+define { i32, i64 }* @balloon_add_box_f64_box_f64({ i32, i64 }* %box1, { i32, i64 }* %box2) {
+entry:
+  %raw1 = call double @unbox_balloon_float({ i32, i64 }* %box1)
+  %raw2 = call double @unbox_balloon_float({ i32, i64 }* %box2)
+  %sum = fadd double %raw1, %raw2
+  %boxed_sum = call { i32, i64 }* @box_balloon_float(double %sum)
+  ret { i32, i64 }* %boxed_sum
+}
+
+define { i32, i64 }* @balloon_add_box_i64_box_f64({ i32, i64 }* %box1, { i32, i64 }* %box2) {
+entry:
+  %raw1 = call i64 @unbox_balloon_int({ i32, i64 }* %box1)
+  %raw2 = call double @unbox_balloon_float({ i32, i64 }* %box2)
+  %raw1_float = sitofp i64 %raw1 to double
+  %sum = fadd double %raw1_float, %raw2
+  %boxed_sum = call { i32, i64 }* @box_balloon_float(double %sum)
+  ret { i32, i64 }* %boxed_sum
+}
+
+define { i32, i64 }* @balloon_add_box_i64_box_i64({ i32, i64 }* %box1, { i32, i64 }* %box2) {
+entry:
+  %raw1 = call i64 @unbox_balloon_int({ i32, i64 }* %box1)
+  %raw2 = call i64 @unbox_balloon_int({ i32, i64 }* %box2)
+  %sum = add i64 %raw1, %raw2
+  %boxed_sum = call { i32, i64 }* @box_balloon_int(i64 %sum)
+  ret { i32, i64 }* %boxed_sum
+}
+
+define { i32, i64 }* @balloon_add_box_box({ i32, i64 }* %box1, { i32, i64 }* %box2) {
+entry:
+  %tag1 = call i32 @unbox_tag({ i32, i64 }* %box1)
+  %tag2 = call i32 @unbox_tag({ i32, i64 }* %box2)
+  switch i32 %tag1, label %unknown_add_types [
+    i32 0, label %int_wildcard
+    i32 1, label %float_wildcard
+  ]
+
+unknown_add_types:                                ; preds = %entry, %float_wildcard, %int_wildcard
+  %errorbox = call { i32, i64 }* @box_balloon_int(i64 -42)
+  ret { i32, i64 }* %errorbox
+
+float_float:                                      ; preds = %float_wildcard
+  %sum = call { i32, i64 }* @balloon_add_box_f64_box_f64({ i32, i64 }* %box1, { i32, i64 }* %box2)
+  ret { i32, i64 }* %sum
+
+int_int:                                          ; preds = %int_wildcard
+  %sum1 = call { i32, i64 }* @balloon_add_box_i64_box_i64({ i32, i64 }* %box1, { i32, i64 }* %box2)
+  ret { i32, i64 }* %sum1
+
+float_int:                                        ; preds = %float_wildcard
+  %sum2 = call { i32, i64 }* @balloon_add_box_i64_box_f64({ i32, i64 }* %box2, { i32, i64 }* %box1)
+  ret { i32, i64 }* %sum2
+
+int_float:                                        ; preds = %int_wildcard
+  %sum3 = call { i32, i64 }* @balloon_add_box_i64_box_f64({ i32, i64 }* %box1, { i32, i64 }* %box2)
+  ret { i32, i64 }* %sum3
+
+int_wildcard:                                     ; preds = %entry
+  switch i32 %tag2, label %unknown_add_types [
+    i32 0, label %int_int
+    i32 1, label %int_float
+  ]
+
+float_wildcard:                                   ; preds = %entry
+  switch i32 %tag2, label %unknown_add_types [
+    i32 0, label %float_int
+    i32 1, label %float_float
+  ]
+}
diff --git a/src/llvm_interpreter.rs b/src/llvm_interpreter.rs
index 49c7c8f..ef993f6 100644
--- a/src/llvm_interpreter.rs
+++ b/src/llvm_interpreter.rs
@@ -1,5 +1,3 @@
-// sample LLVM code lifted from
-// https://github.com/Wilfred/bfc/blob/master/src/llvm.rs
 use std::rc::Rc;
 use std::cell::RefCell;
 use std::fmt;