Emit correct alignment information for loads/store of small aggregates

src/librustc_trans/trans/adt.rs

@@ -880,7 +880,7 @@ pub fn trans_set_discr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, r: &Repr<'tcx>,
         CEnum(ity, min, max) => {
             assert_discr_in_range(ity, min, max, discr);
             Store(bcx, C_integral(ll_inttype(bcx.ccx(), ity), discr as u64, true),
-                  val)
+                  val);
         }
         General(ity, ref cases, dtor) => {
             if dtor_active(dtor) {
@@ -889,7 +889,7 @@ pub fn trans_set_discr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, r: &Repr<'tcx>,
                 Store(bcx, C_u8(bcx.ccx(), DTOR_NEEDED as usize), ptr);
             }
             Store(bcx, C_integral(ll_inttype(bcx.ccx(), ity), discr as u64, true),
-                  GEPi(bcx, val, &[0, 0]))
+                  GEPi(bcx, val, &[0, 0]));
         }
         Univariant(ref st, dtor) => {
             assert_eq!(discr, 0);
@@ -901,14 +901,14 @@ pub fn trans_set_discr<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, r: &Repr<'tcx>,
         RawNullablePointer { nndiscr, nnty, ..} => {
             if discr != nndiscr {
                 let llptrty = type_of::sizing_type_of(bcx.ccx(), nnty);
-                Store(bcx, C_null(llptrty), val)
+                Store(bcx, C_null(llptrty), val);
             }
         }
         StructWrappedNullablePointer { nndiscr, ref discrfield, .. } => {
             if discr != nndiscr {
                 let llptrptr = GEPi(bcx, val, &discrfield[..]);
                 let llptrty = val_ty(llptrptr).element_type();
-                Store(bcx, C_null(llptrty), llptrptr)
+                Store(bcx, C_null(llptrty), llptrptr);
             }
         }
     }

src/librustc_trans/trans/base.rs

@@ -765,9 +765,14 @@ pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
     }
 
     let ptr = to_arg_ty_ptr(cx, ptr, t);
+    let align = type_of::align_of(cx.ccx(), t);
 
     if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
-        return Load(cx, ptr);
+        let load = Load(cx, ptr);
+        unsafe {
+            llvm::LLVMSetAlignment(load, align);
+        }
+        return load;
     }
 
     unsafe {
@@ -793,13 +798,24 @@ pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
         Load(cx, ptr)
     };
 
+    unsafe {
+        llvm::LLVMSetAlignment(val, align);
+    }
+
     from_arg_ty(cx, val, t)
 }
 
 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
 /// differs from the type used for SSA values.
 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
-    Store(cx, to_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
+    if cx.unreachable.get() {
+        return;
+    }
+
+    let store = Store(cx, to_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
+    unsafe {
+        llvm::LLVMSetAlignment(store, type_of::align_of(cx.ccx(), t));
+    }
 }
 
 pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {

src/librustc_trans/trans/build.rs

@@ -646,13 +646,13 @@ pub fn LoadNonNull(cx: Block, ptr: ValueRef) -> ValueRef {
     }
 }
 
-pub fn Store(cx: Block, val: ValueRef, ptr: ValueRef) {
-    if cx.unreachable.get() { return; }
+pub fn Store(cx: Block, val: ValueRef, ptr: ValueRef) -> ValueRef {
+    if cx.unreachable.get() { return C_nil(cx.ccx()); }
     B(cx).store(val, ptr)
 }
 
-pub fn VolatileStore(cx: Block, val: ValueRef, ptr: ValueRef) {
-    if cx.unreachable.get() { return; }
+pub fn VolatileStore(cx: Block, val: ValueRef, ptr: ValueRef) -> ValueRef {
+    if cx.unreachable.get() { return C_nil(cx.ccx()); }
     B(cx).volatile_store(val, ptr)
 }
 

src/librustc_trans/trans/builder.rs

@@ -509,18 +509,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         value
     }
 
-    pub fn store(&self, val: ValueRef, ptr: ValueRef) {
+    pub fn store(&self, val: ValueRef, ptr: ValueRef) -> ValueRef {
         debug!("Store {} -> {}",
                self.ccx.tn().val_to_string(val),
                self.ccx.tn().val_to_string(ptr));
         assert!(!self.llbuilder.is_null());
         self.count_insn("store");
         unsafe {
-            llvm::LLVMBuildStore(self.llbuilder, val, ptr);
+            llvm::LLVMBuildStore(self.llbuilder, val, ptr)
         }
     }
 
-    pub fn volatile_store(&self, val: ValueRef, ptr: ValueRef) {
+    pub fn volatile_store(&self, val: ValueRef, ptr: ValueRef) -> ValueRef {
         debug!("Store {} -> {}",
                self.ccx.tn().val_to_string(val),
                self.ccx.tn().val_to_string(ptr));
@@ -529,6 +529,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         unsafe {
             let insn = llvm::LLVMBuildStore(self.llbuilder, val, ptr);
             llvm::LLVMSetVolatile(insn, llvm::True);
+            insn
         }
     }
 

src/librustc_trans/trans/foreign.rs

@@ -802,7 +802,9 @@ pub fn trans_rust_fn_with_foreign_abi<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                     // appropriately sized integer and we have to convert it
                     let tmp = builder.bitcast(llforeign_arg,
                                               type_of::arg_type_of(ccx, rust_ty).ptr_to());
-                    builder.load(tmp)
+                    let load = builder.load(tmp);
+                    llvm::LLVMSetAlignment(load, type_of::align_of(ccx, rust_ty));
+                    load
                 } else {
                     builder.load(llforeign_arg)
                 }

src/librustc_trans/trans/intrinsic.rs

@@ -456,13 +456,20 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
         (_, "volatile_load") => {
             let tp_ty = *substs.types.get(FnSpace, 0);
             let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
-            from_arg_ty(bcx, VolatileLoad(bcx, ptr), tp_ty)
+            let load = VolatileLoad(bcx, ptr);
+            unsafe {
+                llvm::LLVMSetAlignment(load, type_of::align_of(ccx, tp_ty));
+            }
+            from_arg_ty(bcx, load, tp_ty)
         },
         (_, "volatile_store") => {
             let tp_ty = *substs.types.get(FnSpace, 0);
             let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
             let val = to_arg_ty(bcx, llargs[1], tp_ty);
-            VolatileStore(bcx, val, ptr);
+            let store = VolatileStore(bcx, val, ptr);
+            unsafe {
+                llvm::LLVMSetAlignment(store, type_of::align_of(ccx, tp_ty));
+            }
             C_nil(ccx)
         },