Auto merge of #25770 - dotdash:bool_transmute, r=eddyb

Fixes #25746

Author: bors

src/librustc_trans/trans/base.rs

@@ -785,7 +785,7 @@ pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
         if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
             let val = llvm::LLVMGetInitializer(global);
             if !val.is_null() {
-                return from_arg_ty(cx, val, t);
+                return to_arg_ty(cx, val, t);
             }
         }
     }
@@ -807,7 +807,7 @@ pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
         llvm::LLVMSetAlignment(val, align);
     }
 
-    from_arg_ty(cx, val, t)
+    to_arg_ty(cx, val, t)
 }
 
 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
@@ -817,21 +817,21 @@ pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t
         return;
     }
 
-    let store = Store(cx, to_arg_ty(cx, v, t), to_arg_ty_ptr(cx, dst, t));
+    let store = Store(cx, from_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 {
+pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
     if ty::type_is_bool(ty) {
         ZExt(bcx, val, Type::i8(bcx.ccx()))
     } else {
         val
     }
 }
 
-pub fn from_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
+pub fn to_arg_ty(bcx: Block, val: ValueRef, ty: Ty) -> ValueRef {
     if ty::type_is_bool(ty) {
         Trunc(bcx, val, Type::i1(bcx.ccx()))
     } else {

src/librustc_trans/trans/intrinsic.rs

@@ -223,7 +223,7 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
                     let val = if datum.kind.is_by_ref() {
                         load_ty(bcx, datum.val, datum.ty)
                     } else {
-                        datum.val
+                        from_arg_ty(bcx, datum.val, datum.ty)
                     };
 
                     let cast_val = BitCast(bcx, val, llret_ty);
@@ -490,12 +490,12 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
             unsafe {
                 llvm::LLVMSetAlignment(load, type_of::align_of(ccx, tp_ty));
             }
-            from_arg_ty(bcx, load, tp_ty)
+            to_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);
+            let val = from_arg_ty(bcx, llargs[1], tp_ty);
             let store = VolatileStore(bcx, val, ptr);
             unsafe {
                 llvm::LLVMSetAlignment(store, type_of::align_of(ccx, tp_ty));
@@ -777,8 +777,8 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
 
                     let tp_ty = *substs.types.get(FnSpace, 0);
                     let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
-                    let cmp = to_arg_ty(bcx, llargs[1], tp_ty);
-                    let src = to_arg_ty(bcx, llargs[2], tp_ty);
+                    let cmp = from_arg_ty(bcx, llargs[1], tp_ty);
+                    let src = from_arg_ty(bcx, llargs[2], tp_ty);
                     let res = AtomicCmpXchg(bcx, ptr, cmp, src, order,
                                             strongest_failure_ordering);
                     ExtractValue(bcx, res, 0)
@@ -787,12 +787,12 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
                 "load" => {
                     let tp_ty = *substs.types.get(FnSpace, 0);
                     let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
-                    from_arg_ty(bcx, AtomicLoad(bcx, ptr, order), tp_ty)
+                    to_arg_ty(bcx, AtomicLoad(bcx, ptr, order), tp_ty)
                 }
                 "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);
+                    let val = from_arg_ty(bcx, llargs[1], tp_ty);
                     AtomicStore(bcx, val, ptr, order);
                     C_nil(ccx)
                 }
@@ -826,7 +826,7 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
 
                     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);
+                    let val = from_arg_ty(bcx, llargs[1], tp_ty);
                     AtomicRMW(bcx, atom_op, ptr, val, order)
                 }
             }

src/test/run-pass/issue-25746-bool-transmute.rs

@@ -0,0 +1,20 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::mem::transmute;
+
+fn main() {
+    unsafe {
+        let _: i8 = transmute(false);
+        let _: i8 = transmute(true);
+        let _: bool = transmute(0u8);
+        let _: bool = transmute(1u8);
+    }
+}