+use llvm_sys::{
+    core::{
+        LLVMBuildFAdd, LLVMBuildFCmp, LLVMBuildFMul, LLVMBuildFSub, LLVMBuildRet, LLVMBuildUIToFP,
+        LLVMCreateBuilderInContext, LLVMDisposeBuilder, LLVMPositionBuilderAtEnd,
+    },
+    prelude::{LLVMBuilderRef, LLVMValueRef},
+    LLVMRealPredicate,
+};
+
+use std::marker::PhantomData;
+
+use super::{BasicBlock, FnValue, Module, Type, Value};
+
+// Definition of LLVM C API functions using our `repr(transparent)` types.
+extern "C" {
+    fn LLVMBuildCall2(
+        arg1: LLVMBuilderRef,
+        arg2: Type<'_>,
+        Fn: FnValue<'_>,
+        Args: *mut Value<'_>,
+        NumArgs: ::libc::c_uint,
+        Name: *const ::libc::c_char,
+    ) -> LLVMValueRef;
+}
+
+/// Wrapper for a LLVM IR Builder.
+pub struct IRBuilder<'llvm> {
+    builder: LLVMBuilderRef,
+    _ctx: PhantomData<&'llvm ()>,
+}
+
+impl<'llvm> IRBuilder<'llvm> {
+    /// Create a new LLVM IR Builder with the `module`s context.
+    ///
+    /// # Panics
+    ///
+    /// Panics if creating the IR Builder fails.
+    pub fn with_ctx(module: &'llvm Module) -> IRBuilder<'llvm> {
+        let builder = unsafe { LLVMCreateBuilderInContext(module.ctx()) };
+        assert!(!builder.is_null());
+
+        IRBuilder {
+            builder,
+            _ctx: PhantomData,
+        }
+    }
+
+    /// Position the IR Builder at the end of the given Basic Block.
+    pub fn pos_at_end(&self, bb: BasicBlock<'llvm>) {
+        unsafe {
+            LLVMPositionBuilderAtEnd(self.builder, bb.0);
+        }
+    }
+
+    /// Emit a [fadd](https://llvm.org/docs/LangRef.html#fadd-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn fadd(&self, lhs: Value<'llvm>, rhs: Value<'llvm>) -> Value<'llvm> {
+        debug_assert!(lhs.is_f64(), "fadd: Expected f64 as lhs operand!");
+        debug_assert!(rhs.is_f64(), "fadd: Expected f64 as rhs operand!");
+
+        let value_ref = unsafe {
+            LLVMBuildFAdd(
+                self.builder,
+                lhs.value_ref(),
+                rhs.value_ref(),
+                b"fadd\0".as_ptr().cast(),
+            )
+        };
+        Value::new(value_ref)
+    }
+
+    /// Emit a [fsub](https://llvm.org/docs/LangRef.html#fsub-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn fsub(&self, lhs: Value<'llvm>, rhs: Value<'llvm>) -> Value<'llvm> {
+        debug_assert!(lhs.is_f64(), "fsub: Expected f64 as lhs operand!");
+        debug_assert!(rhs.is_f64(), "fsub: Expected f64 as rhs operand!");
+
+        let value_ref = unsafe {
+            LLVMBuildFSub(
+                self.builder,
+                lhs.value_ref(),
+                rhs.value_ref(),
+                b"fsub\0".as_ptr().cast(),
+            )
+        };
+        Value::new(value_ref)
+    }
+
+    /// Emit a [fmul](https://llvm.org/docs/LangRef.html#fmul-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn fmul(&self, lhs: Value<'llvm>, rhs: Value<'llvm>) -> Value<'llvm> {
+        debug_assert!(lhs.is_f64(), "fmul: Expected f64 as lhs operand!");
+        debug_assert!(rhs.is_f64(), "fmul: Expected f64 as rhs operand!");
+
+        let value_ref = unsafe {
+            LLVMBuildFMul(
+                self.builder,
+                lhs.value_ref(),
+                rhs.value_ref(),
+                b"fmul\0".as_ptr().cast(),
+            )
+        };
+        Value::new(value_ref)
+    }
+
+    /// Emit a [fcmult](https://llvm.org/docs/LangRef.html#fcmp-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn fcmpult(&self, lhs: Value<'llvm>, rhs: Value<'llvm>) -> Value<'llvm> {
+        debug_assert!(lhs.is_f64(), "fcmplt: Expected f64 as lhs operand!");
+        debug_assert!(rhs.is_f64(), "fcmplt: Expected f64 as rhs operand!");
+
+        let value_ref = unsafe {
+            LLVMBuildFCmp(
+                self.builder,
+                LLVMRealPredicate::LLVMRealULT,
+                lhs.value_ref(),
+                rhs.value_ref(),
+                b"fcmplt\0".as_ptr().cast(),
+            )
+        };
+        Value::new(value_ref)
+    }
+
+    /// Emit a [uitofp](https://llvm.org/docs/LangRef.html#uitofp-to-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn uitofp(&self, val: Value<'llvm>, dest_type: Type<'llvm>) -> Value<'llvm> {
+        debug_assert!(val.is_int(), "uitofp: Expected integer operand!");
+
+        let value_ref = unsafe {
+            LLVMBuildUIToFP(
+                self.builder,
+                val.value_ref(),
+                dest_type.type_ref(),
+                b"uitofp\0".as_ptr().cast(),
+            )
+        };
+        Value::new(value_ref)
+    }
+
+    /// Emit a [call](https://llvm.org/docs/LangRef.html#call-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn call(&self, fn_value: FnValue<'llvm>, args: &mut [Value<'llvm>]) -> Value<'llvm> {
+        let value_ref = unsafe {
+            LLVMBuildCall2(
+                self.builder,
+                fn_value.ret_type(),
+                fn_value,
+                args.as_mut_ptr(),
+                args.len() as libc::c_uint,
+                b"call\0".as_ptr().cast(),
+            )
+        };
+        Value::new(value_ref)
+    }
+
+    /// Emit a [ret](https://llvm.org/docs/LangRef.html#ret-instruction) instruction.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn ret(&self, ret: Value<'llvm>) {
+        let ret = unsafe { LLVMBuildRet(self.builder, ret.value_ref()) };
+        assert!(!ret.is_null());
+    }
+}
+
+impl Drop for IRBuilder<'_> {
+    fn drop(&mut self) {
+        unsafe { LLVMDisposeBuilder(self.builder) }
+    }
+}
+

+