diff --git a/src/abi.rs b/src/abi.rs
index 5600f1ba8a9df..f601cd95f2a68 100644
--- a/src/abi.rs
+++ b/src/abi.rs
@@ -1,4 +1,6 @@
-use gccjit::{FnAttribute, ToLValue, ToRValue, Type};
+#[cfg(feature = "master")]
+use gccjit::FnAttribute;
+use gccjit::{ToLValue, ToRValue, Type};
 use rustc_codegen_ssa::traits::{AbiBuilderMethods, BaseTypeMethods};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::bug;
@@ -101,6 +103,7 @@ pub struct FnAbiGcc<'gcc> {
     pub arguments_type: Vec<Type<'gcc>>,
     pub is_c_variadic: bool,
     pub on_stack_param_indices: FxHashSet<usize>,
+    #[cfg(feature = "master")]
     pub fn_attributes: Vec<FnAttribute<'gcc>>,
 }
 
@@ -129,6 +132,7 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
                     cx.type_void()
                 }
             };
+        #[cfg(feature = "master")]
         let mut non_null_args = Vec::new();
 
         #[cfg(feature = "master")]
@@ -190,14 +194,13 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
         } else {
             vec![FnAttribute::NonNull(non_null_args)]
         };
-        #[cfg(not(feature = "master"))]
-        let fn_attrs = Vec::new();
 
         FnAbiGcc {
             return_type,
             arguments_type: argument_tys,
             is_c_variadic: self.c_variadic,
             on_stack_param_indices,
+            #[cfg(feature = "master")]
             fn_attributes: fn_attrs,
         }
     }
diff --git a/src/common.rs b/src/common.rs
index 5f54cb16d8e2b..93fe27e547aef 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -424,35 +424,35 @@ impl<'gcc, 'tcx> TypeReflection<'gcc, 'tcx> for Type<'gcc> {
     }
 
     fn is_i8(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.i8_type
+        self.is_compatible_with(cx.i8_type)
     }
 
     fn is_u8(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.u8_type
+        self.is_compatible_with(cx.u8_type)
     }
 
     fn is_i16(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.i16_type
+        self.is_compatible_with(cx.i16_type)
     }
 
     fn is_u16(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.u16_type
+        self.is_compatible_with(cx.u16_type)
     }
 
     fn is_i32(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.i32_type
+        self.is_compatible_with(cx.i32_type)
     }
 
     fn is_u32(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.u32_type
+        self.is_compatible_with(cx.u32_type)
     }
 
     fn is_i64(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.i64_type
+        self.is_compatible_with(cx.i64_type)
     }
 
     fn is_u64(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
-        self.unqualified() == cx.u64_type
+        self.is_compatible_with(cx.u64_type)
     }
 
     fn is_i128(&self, cx: &CodegenCx<'gcc, 'tcx>) -> bool {
diff --git a/src/context.rs b/src/context.rs
index dcebd92a61c69..243556a0e5232 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -129,19 +129,39 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     pub fn new(context: &'gcc Context<'gcc>, codegen_unit: &'tcx CodegenUnit<'tcx>, tcx: TyCtxt<'tcx>, supports_128bit_integers: bool) -> Self {
         let check_overflow = tcx.sess.overflow_checks();
 
-        let i8_type = context.new_c_type(CType::Int8t);
-        let i16_type = context.new_c_type(CType::Int16t);
-        let i32_type = context.new_c_type(CType::Int32t);
-        let i64_type = context.new_c_type(CType::Int64t);
-        let u8_type = context.new_c_type(CType::UInt8t);
-        let u16_type = context.new_c_type(CType::UInt16t);
-        let u32_type = context.new_c_type(CType::UInt32t);
-        let u64_type = context.new_c_type(CType::UInt64t);
+        let create_type = |ctype, rust_type| {
+            let layout = tcx.layout_of(ParamEnv::reveal_all().and(rust_type)).unwrap();
+            let align = layout.align.abi.bytes();
+            #[cfg(feature="master")]
+            {
+                context.new_c_type(ctype).get_aligned(align)
+            }
+            #[cfg(not(feature="master"))]
+            {
+                // Since libgccjit 12 doesn't contain the fix to compare aligned integer types,
+                // only align u128 and i128.
+                if layout.ty.int_size_and_signed(tcx).0.bytes() == 16 {
+                    context.new_c_type(ctype).get_aligned(align)
+                }
+                else {
+                    context.new_c_type(ctype)
+                }
+            }
+        };
+
+        let i8_type = create_type(CType::Int8t, tcx.types.i8);
+        let i16_type = create_type(CType::Int16t, tcx.types.i16);
+        let i32_type = create_type(CType::Int32t, tcx.types.i32);
+        let i64_type = create_type(CType::Int64t, tcx.types.i64);
+        let u8_type = create_type(CType::UInt8t, tcx.types.u8);
+        let u16_type = create_type(CType::UInt16t, tcx.types.u16);
+        let u32_type = create_type(CType::UInt32t, tcx.types.u32);
+        let u64_type = create_type(CType::UInt64t, tcx.types.u64);
 
         let (i128_type, u128_type) =
             if supports_128bit_integers {
-                let i128_type = context.new_c_type(CType::Int128t).get_aligned(8); // TODO(antoyo): should the alignment be hard-coded?;
-                let u128_type = context.new_c_type(CType::UInt128t).get_aligned(8); // TODO(antoyo): should the alignment be hard-coded?;
+                let i128_type = create_type(CType::Int128t, tcx.types.i128);
+                let u128_type = create_type(CType::UInt128t, tcx.types.u128);
                 (i128_type, u128_type)
             }
             else {
diff --git a/src/declare.rs b/src/declare.rs
index 0b583c074dd23..247454fa58e14 100644
--- a/src/declare.rs
+++ b/src/declare.rs
@@ -85,10 +85,12 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             arguments_type,
             is_c_variadic,
             on_stack_param_indices,
+            #[cfg(feature="master")]
             fn_attributes,
         } = fn_abi.gcc_type(self);
         let func = declare_raw_fn(self, name, () /*fn_abi.llvm_cconv()*/, return_type, &arguments_type, is_c_variadic);
         self.on_stack_function_params.borrow_mut().insert(func, on_stack_param_indices);
+        #[cfg(feature="master")]
         for fn_attr in fn_attributes {
             func.add_attribute(fn_attr);
         }