Add Type::int_width for retrieving integer's bit width.

Author: huonw

src/librustc_trans/trans/base.rs

@@ -847,26 +847,24 @@ pub fn cast_shift_rhs<F, G>(op: ast::BinOp,
     G: FnOnce(ValueRef, Type) -> ValueRef,
 {
     // Shifts may have any size int on the rhs
-    unsafe {
-        if ast_util::is_shift_binop(op) {
-            let mut rhs_llty = val_ty(rhs);
-            let mut lhs_llty = val_ty(lhs);
-            if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
-            if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
-            let rhs_sz = llvm::LLVMGetIntTypeWidth(rhs_llty.to_ref());
-            let lhs_sz = llvm::LLVMGetIntTypeWidth(lhs_llty.to_ref());
-            if lhs_sz < rhs_sz {
-                trunc(rhs, lhs_llty)
-            } else if lhs_sz > rhs_sz {
-                // FIXME (#1877: If shifting by negative
-                // values becomes not undefined then this is wrong.
-                zext(rhs, lhs_llty)
-            } else {
-                rhs
-            }
+    if ast_util::is_shift_binop(op) {
+        let mut rhs_llty = val_ty(rhs);
+        let mut lhs_llty = val_ty(lhs);
+        if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
+        if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
+        let rhs_sz = rhs_llty.int_width();
+        let lhs_sz = lhs_llty.int_width();
+        if lhs_sz < rhs_sz {
+            trunc(rhs, lhs_llty)
+        } else if lhs_sz > rhs_sz {
+            // FIXME (#1877: If shifting by negative
+            // values becomes not undefined then this is wrong.
+            zext(rhs, lhs_llty)
         } else {
             rhs
         }
+    } else {
+        rhs
     }
 }
 

src/librustc_trans/trans/cabi_aarch64.rs

@@ -10,7 +10,6 @@
 
 #![allow(non_upper_case_globals)]
 
-use llvm;
 use llvm::{Integer, Pointer, Float, Double, Struct, Array, Vector};
 use llvm::{StructRetAttribute, ZExtAttribute};
 use trans::cabi::{FnType, ArgType};
@@ -30,11 +29,7 @@ fn align(off: uint, ty: Type) -> uint {
 
 fn ty_align(ty: Type) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-            }
-        }
+        Integer => ((ty.int_width() as uint) + 7) / 8,
         Pointer => 8,
         Float => 4,
         Double => 8,
@@ -61,11 +56,7 @@ fn ty_align(ty: Type) -> uint {
 
 fn ty_size(ty: Type) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-            }
-        }
+        Integer => ((ty.int_width() as uint) + 7) / 8,
         Pointer => 8,
         Float => 4,
         Double => 8,

src/librustc_trans/trans/cabi_arm.rs

@@ -10,7 +10,6 @@
 
 #![allow(non_upper_case_globals)]
 
-use llvm;
 use llvm::{Integer, Pointer, Float, Double, Struct, Array, Vector};
 use llvm::{StructRetAttribute, ZExtAttribute};
 use trans::cabi::{FnType, ArgType};
@@ -37,11 +36,7 @@ fn align(off: uint, ty: Type, align_fn: TyAlignFn) -> uint {
 
 fn general_ty_align(ty: Type) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-            }
-        }
+        Integer => ((ty.int_width() as uint) + 7) / 8,
         Pointer => 4,
         Float => 4,
         Double => 8,
@@ -75,11 +70,7 @@ fn general_ty_align(ty: Type) -> uint {
 //    /iPhoneOSABIReference/Articles/ARMv6FunctionCallingConventions.html
 fn ios_ty_align(ty: Type) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                cmp::min(4, ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8)
-            }
-        }
+        Integer => cmp::min(4, ((ty.int_width() as uint) + 7) / 8),
         Pointer => 4,
         Float => 4,
         Double => 4,
@@ -106,11 +97,7 @@ fn ios_ty_align(ty: Type) -> uint {
 
 fn ty_size(ty: Type, align_fn: TyAlignFn) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-            }
-        }
+        Integer => ((ty.int_width() as uint) + 7) / 8,
         Pointer => 4,
         Float => 4,
         Double => 8,

src/librustc_trans/trans/cabi_mips.rs

@@ -30,11 +30,7 @@ fn align(off: uint, ty: Type) -> uint {
 
 fn ty_align(ty: Type) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-            }
-        }
+        Integer => ((ty.int_width() as uint) + 7) / 8,
         Pointer => 4,
         Float => 4,
         Double => 8,
@@ -61,11 +57,7 @@ fn ty_align(ty: Type) -> uint {
 
 fn ty_size(ty: Type) -> uint {
     match ty.kind() {
-        Integer => {
-            unsafe {
-                ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-            }
-        }
+        Integer => ((ty.int_width() as uint) + 7) / 8,
         Pointer => 4,
         Float => 4,
         Double => 8,

src/librustc_trans/trans/cabi_x86_64.rs

@@ -14,7 +14,6 @@
 #![allow(non_upper_case_globals)]
 use self::RegClass::*;
 
-use llvm;
 use llvm::{Integer, Pointer, Float, Double};
 use llvm::{Struct, Array, Attribute, Vector};
 use llvm::{StructRetAttribute, ByValAttribute, ZExtAttribute};
@@ -94,11 +93,7 @@ fn classify_ty(ty: Type) -> Vec<RegClass> {
 
     fn ty_align(ty: Type) -> uint {
         match ty.kind() {
-            Integer => {
-                unsafe {
-                    ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-                }
-            }
+            Integer => ((ty.int_width() as uint) + 7) / 8,
             Pointer => 8,
             Float => 4,
             Double => 8,
@@ -125,11 +120,7 @@ fn classify_ty(ty: Type) -> Vec<RegClass> {
 
     fn ty_size(ty: Type) -> uint {
         match ty.kind() {
-            Integer => {
-                unsafe {
-                    ((llvm::LLVMGetIntTypeWidth(ty.to_ref()) as uint) + 7) / 8
-                }
-            }
+            Integer => (ty.int_width() as uint + 7) / 8,
             Pointer => 8,
             Float => 4,
             Double => 8,

src/librustc_trans/trans/expr.rs

@@ -1906,18 +1906,16 @@ fn int_cast(bcx: Block,
             signed: bool)
             -> ValueRef {
     let _icx = push_ctxt("int_cast");
-    unsafe {
-        let srcsz = llvm::LLVMGetIntTypeWidth(llsrctype.to_ref());
-        let dstsz = llvm::LLVMGetIntTypeWidth(lldsttype.to_ref());
-        return if dstsz == srcsz {
-            BitCast(bcx, llsrc, lldsttype)
-        } else if srcsz > dstsz {
-            TruncOrBitCast(bcx, llsrc, lldsttype)
-        } else if signed {
-            SExtOrBitCast(bcx, llsrc, lldsttype)
-        } else {
-            ZExtOrBitCast(bcx, llsrc, lldsttype)
-        };
+    let srcsz = llsrctype.int_width();
+    let dstsz = lldsttype.int_width();
+    return if dstsz == srcsz {
+        BitCast(bcx, llsrc, lldsttype)
+    } else if srcsz > dstsz {
+        TruncOrBitCast(bcx, llsrc, lldsttype)
+    } else if signed {
+        SExtOrBitCast(bcx, llsrc, lldsttype)
+    } else {
+        ZExtOrBitCast(bcx, llsrc, lldsttype)
     }
 }
 

src/librustc_trans/trans/type_.rs

@@ -333,6 +333,13 @@ impl Type {
             _ => panic!("llvm_float_width called on a non-float type")
         }
     }
+
+    /// Retrieve the bit width of the integer type `self`.
+    pub fn int_width(&self) -> u64 {
+        unsafe {
+            llvm::LLVMGetIntTypeWidth(self.to_ref()) as u64
+        }
+    }
 }