Implement bitwise shift operation

include/operator.hpp

@@ -18,6 +18,8 @@ enum class BinaryOperator : std::uint8_t {
   kAnd,
   kXor,
   kOr,
+  kShl,
+  kShr,
 };
 
 enum class UnaryOperator : std::uint8_t {

parser.y

@@ -305,8 +305,8 @@ add_expr: mul_expr { $$ = $1; }
 
 /* 6.5.7 Bitwise shift operators */
 shift_expr: add_expr { $$ = $1; }
-  | shift_expr SHIFT_LEFT add_expr
-  | shift_expr SHIFT_RIGHT add_expr
+  | shift_expr SHIFT_LEFT add_expr { $$ = std::make_unique<BinaryExprNode>(Loc(@2), BinaryOperator::kShl, $1, $3); }
+  | shift_expr SHIFT_RIGHT add_expr { $$ = std::make_unique<BinaryExprNode>(Loc(@2), BinaryOperator::kShr, $1, $3); }
   ;
 
 /* 6.5.8 Relational operators */

src/ast_dumper.cpp

@@ -41,6 +41,10 @@ std::string GetBinaryOperator(BinaryOperator op) {
       return "^";
     case BinaryOperator::kOr:
       return "|";
+    case BinaryOperator::kShl:
+      return "<<";
+    case BinaryOperator::kShr:
+      return ">>";
     default:
       return "Unknown";
   }

src/qbe_ir_generator.cpp

@@ -70,6 +70,13 @@ std::string GetBinaryOperator(BinaryOperator op) {
       return "xor";
     case BinaryOperator::kOr:
       return "or";
+    case BinaryOperator::kShl:
+      return "shl";
+    // NOTE: Arithmetic shift right (sar) is akin to dividing by a power of two
+    // for non-negative numbers. For negatives, it's implementation-defined, so
+    // we opt for arithmetic shifting.
+    case BinaryOperator::kShr:
+      return "sar";
     default:
       return "Unknown";
   }

test/codegen/bin_expr.c

@@ -3,5 +3,9 @@ int main() {
   __builtin_print(5 | 4);
   __builtin_print(5 ^ 4);
   __builtin_print(5 & 4);
+  __builtin_print(1 << 16);
+  __builtin_print(-1 << 31);
+  __builtin_print(65536 >> 16);
+  __builtin_print(-1 >> 16);
   return 0;
 }

test/codegen/bin_expr.exp

@@ -2,3 +2,7 @@
 5
 1
 4
+65536
+-2147483648
+1
+-1

test/typecheck/bin_expr.c

@@ -8,4 +8,6 @@ int main() {
   1 & 4;
   1 | 2;
   1 ^ 3;
+  1 << 16;
+  65536 >> 16;
 }

test/typecheck/bin_expr.exp

@@ -47,3 +47,11 @@ ProgramNode <1:1>
         BinaryExprNode <10:5> int ^
           IntConstExprNode <10:3> 1: int
           IntConstExprNode <10:7> 3: int
+      ExprStmtNode <11:3>
+        BinaryExprNode <11:5> int <<
+          IntConstExprNode <11:3> 1: int
+          IntConstExprNode <11:8> 16: int
+      ExprStmtNode <12:3>
+        BinaryExprNode <12:9> int >>
+          IntConstExprNode <12:3> 65536: int
+          IntConstExprNode <12:12> 16: int