Add bitwise assembly helpers

std/dispatch.solc

@@ -82,11 +82,8 @@ forall name payability args rets fn
 => instance Method(name,payability,args,rets,fn):Selector {
     function compute(prx : Proxy(Method(name,payability,args,rets,fn))) -> bytes4 {
         // let hash : word = keccakLit(sigStr(prx));
-	let hash = keccakLit(sigStr(Proxy:Proxy(name))  + "(" + sigStr(Proxy:Proxy(args)) + ")");
-	let res : word;
-        assembly { res := shr(224, hash) }
-
-        return bytes4(res);
+        let hash = keccakLit(sigStr(Proxy:Proxy(name))  + "(" + sigStr(Proxy:Proxy(args)) + ")");
+        return bytes4(bshrWord(224, hash));
     }
 }
 

std/std.solc

@@ -49,6 +49,12 @@ export {
   bytes,
   bytes4(*),
   bytes32(*),
+  bandWord,
+  borWord,
+  bxorWord,
+  bnotWord,
+  bshlWord,
+  bshrWord,
   calldata(*),
   concatLit,
   eqWord,
@@ -411,6 +417,60 @@ function subWord(l: word, r: word) -> word {
     return rw;
 }
 
+// Bitwise AND
+function bandWord(x: word, y: word) -> word {
+    let res: word;
+    assembly {
+        res := and(x, y)
+    }
+    return res;
+}
+
+// Bitwise OR
+function borWord(x: word) -> word {
+    let res: word;
+    assembly {
+        res := or(x)
+    }
+    return res;
+}
+
+// Bitwise XOR
+function bxorWord(x: word) -> word {
+    let res: word;
+    assembly {
+        res := xor(x)
+    }
+    return res;
+}
+
+// Bitwise NOT
+function bnotWord(x: word) -> word {
+    let res: word;
+    assembly {
+        res := not(x)
+    }
+    return res;
+}
+
+// Bitwise SHL
+function bshlWord(x: word, y: word) -> word {
+    let res: word;
+    assembly {
+        res := shl(x, y)
+    }
+    return res;
+}
+
+// Bitwise SHR
+function bshrWord(x: word, y: word) -> word {
+    let res: word;
+    assembly {
+        res := shr(x, y)
+    }
+    return res;
+}
+
 instance word:Eq {
   function eq(x:word, y:word) -> bool {
     return eqWord(x, y);
@@ -1123,9 +1183,7 @@ instance bool:ABIEncode {
 }
 
 function round_up_to_mul_of_32(value:word) -> word {
-  let result : word;
-  assembly { result := and(add(value, 31), not(31)) }
-  return result;
+    return bandWord(value + 31, bnotWord(31));
 }
 
 function encodeIntoFromBytesLike(srcPtr:word, basePtr:word, offset:word, tail:word) -> word {