3 files changed, 75 insertions, 15 deletions

diff --git a/src/llvm/builder.rs b/src/llvm/builder.rs
index 8f581f9..da10231 100644
--- a/src/llvm/builder.rs
+++ b/src/llvm/builder.rs
@@ -10,7 +10,7 @@ use llvm_sys::{
 
 use std::marker::PhantomData;
 
-use super::{BasicBlock, FnValue, Module, Type, Value};
+use super::{BasicBlock, FnValue, Module, PhiValue, Type, Value};
 
 // Definition of LLVM C API functions using our `repr(transparent)` types.
 extern "C" {
@@ -131,8 +131,8 @@ impl<'llvm> IRBuilder<'llvm> {
     ///
     /// 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!");
+        debug_assert!(lhs.is_f64(), "fcmpult: Expected f64 as lhs operand!");
+        debug_assert!(rhs.is_f64(), "fcmpult: Expected f64 as rhs operand!");
 
         let value_ref = unsafe {
             LLVMBuildFCmp(
@@ -140,7 +140,7 @@ impl<'llvm> IRBuilder<'llvm> {
                 LLVMRealPredicate::LLVMRealULT,
                 lhs.value_ref(),
                 rhs.value_ref(),
-                b"fcmplt\0".as_ptr().cast(),
+                b"fcmpult\0".as_ptr().cast(),
             )
         };
         Value::new(value_ref)
@@ -152,8 +152,8 @@ impl<'llvm> IRBuilder<'llvm> {
     ///
     /// Panics if LLVM API returns a `null` pointer.
     pub fn fcmpone(&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!");
+        debug_assert!(lhs.is_f64(), "fcmone: Expected f64 as lhs operand!");
+        debug_assert!(rhs.is_f64(), "fcmone: Expected f64 as rhs operand!");
 
         let value_ref = unsafe {
             LLVMBuildFCmp(
@@ -251,7 +251,7 @@ impl<'llvm> IRBuilder<'llvm> {
         &self,
         phi_type: Type<'llvm>,
         incoming: &[(Value<'llvm>, BasicBlock<'llvm>)],
-    ) -> Value<'llvm> {
+    ) -> PhiValue<'llvm> {
         let phi_ref =
             unsafe { LLVMBuildPhi(self.builder, phi_type.type_ref(), b"phi\0".as_ptr().cast()) };
         assert!(!phi_ref.is_null());
@@ -268,7 +268,7 @@ impl<'llvm> IRBuilder<'llvm> {
             }
         }
 
-        Value::new(phi_ref)
+        PhiValue::new(phi_ref)
     }
 }
 
diff --git a/src/llvm/mod.rs b/src/llvm/mod.rs
index c9f17b6..1eb9c57 100644
--- a/src/llvm/mod.rs
+++ b/src/llvm/mod.rs
@@ -33,7 +33,7 @@ pub use lljit::{LLJit, ResourceTracker};
 pub use module::Module;
 pub use pass_manager::FunctionPassManager;
 pub use type_::Type;
-pub use value::{FnValue, Value};
+pub use value::{FnValue, PhiValue, Value};
 
 struct Error<'llvm>(&'llvm mut libc::c_char);
 
diff --git a/src/llvm/value.rs b/src/llvm/value.rs
index 219c855..912c14e 100644
--- a/src/llvm/value.rs
+++ b/src/llvm/value.rs
@@ -1,9 +1,11 @@
+#![allow(unused)]
+
 use llvm_sys::{
     analysis::{LLVMVerifierFailureAction, LLVMVerifyFunction},
     core::{
-        LLVMAppendExistingBasicBlock, LLVMCountBasicBlocks, LLVMCountParams, LLVMDumpValue,
-        LLVMGetParam, LLVMGetReturnType, LLVMGetValueKind, LLVMGetValueName2, LLVMSetValueName2,
-        LLVMTypeOf,
+        LLVMAddIncoming, LLVMAppendExistingBasicBlock, LLVMCountBasicBlocks, LLVMCountParams,
+        LLVMDumpValue, LLVMGetParam, LLVMGetReturnType, LLVMGetValueKind, LLVMGetValueName2,
+        LLVMIsAFunction, LLVMIsAPHINode, LLVMSetValueName2, LLVMTypeOf,
     },
     prelude::LLVMValueRef,
     LLVMTypeKind, LLVMValueKind,
@@ -43,6 +45,18 @@ impl<'llvm> Value<'llvm> {
         unsafe { LLVMGetValueKind(self.value_ref()) }
     }
 
+    /// Check if value is `function` type.
+    pub(super) fn is_function(&self) -> bool {
+        let cast = unsafe { LLVMIsAFunction(self.value_ref()) };
+        !cast.is_null()
+    }
+
+    /// Check if value is `phinode` type.
+    pub(super) fn is_phinode(&self) -> bool {
+        let cast = unsafe { LLVMIsAPHINode(self.value_ref()) };
+        !cast.is_null()
+    }
+
     /// Dump the LLVM Value to stdout.
     pub fn dump(&self) {
         unsafe { LLVMDumpValue(self.value_ref()) };
@@ -117,9 +131,8 @@ impl<'llvm> FnValue<'llvm> {
     /// Panics if `value_ref` is a null pointer.
     pub(super) fn new(value_ref: LLVMValueRef) -> Self {
         let value = Value::new(value_ref);
-        debug_assert_eq!(
-            value.kind(),
-            LLVMValueKind::LLVMFunctionValueKind,
+        debug_assert!(
+            value.is_function(),
             "Expected a fn value when constructing FnValue!"
         );
 
@@ -175,3 +188,50 @@ impl<'llvm> FnValue<'llvm> {
         }
     }
 }
+
+/// Wrapper for a LLVM Value Reference specialized for contexts where phi values are needed.
+#[derive(Copy, Clone)]
+#[repr(transparent)]
+pub struct PhiValue<'llvm>(Value<'llvm>);
+
+impl<'llvm> Deref for PhiValue<'llvm> {
+    type Target = Value<'llvm>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<'llvm> PhiValue<'llvm> {
+    /// Create a new PhiValue instance.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `value_ref` is a null pointer.
+    pub(super) fn new(value_ref: LLVMValueRef) -> Self {
+        let value = Value::new(value_ref);
+        debug_assert!(
+            value.is_phinode(),
+            "Expected a phinode value when constructing PhiValue!"
+        );
+
+        PhiValue(value)
+    }
+
+    /// Add an incoming value to the end of a PHI list.
+    pub fn add_incoming(&self, ival: Value<'llvm>, ibb: BasicBlock<'llvm>) {
+        debug_assert_eq!(
+            ival.type_of().kind(),
+            self.type_of().kind(),
+            "Type of incoming phi value must be the same as the type used to build the phi node."
+        );
+
+        unsafe {
+            LLVMAddIncoming(
+                self.value_ref(),
+                &mut ival.value_ref() as _,
+                &mut ibb.bb_ref() as _,
+                1,
+            );
+        }
+    }
+}