feat: implement shift operators

4 files changed, 63 insertions, 4 deletions

diff --git a/codegen.c b/codegen.c
index 92a8619..f717c25 100644
--- a/codegen.c
+++ b/codegen.c
@@ -174,6 +174,13 @@ void codegen_binary_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
         printf("  mov rax, rdx\n");
     } else if (ast->node_op == TokenKind_or) {
         printf("  or rax, rdi\n");
+    } else if (ast->node_op == TokenKind_lshift) {
+        printf("  mov rcx, rdi\n");
+        printf("  shl rax, cl\n");
+    } else if (ast->node_op == TokenKind_rshift) {
+        // TODO: check if the operand is signed or unsigned
+        printf("  mov rcx, rdi\n");
+        printf("  sar rax, cl\n");
     } else if (ast->node_op == TokenKind_eq) {
         printf("  cmp rax, rdi\n");
         printf("  sete al\n");
diff --git a/parse.c b/parse.c
index a0b2ff3..fb5c751 100644
--- a/parse.c
+++ b/parse.c
@@ -597,21 +597,36 @@ AstNode* parse_additive_expr(Parser* p) {
     return lhs;
 }
 
-AstNode* parse_relational_expr(Parser* p) {
+AstNode* parse_shift_expr(Parser* p) {
     AstNode* lhs = parse_additive_expr(p);
     while (1) {
         TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_lt || op == TokenKind_le) {
+        if (op == TokenKind_lshift || op == TokenKind_rshift) {
             next_token(p);
             AstNode* rhs = parse_additive_expr(p);
             lhs = ast_new_binary_expr(op, lhs, rhs);
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_relational_expr(Parser* p) {
+    AstNode* lhs = parse_shift_expr(p);
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_lt || op == TokenKind_le) {
+            next_token(p);
+            AstNode* rhs = parse_shift_expr(p);
+            lhs = ast_new_binary_expr(op, lhs, rhs);
         } else if (op == TokenKind_gt) {
             next_token(p);
-            AstNode* rhs = parse_additive_expr(p);
+            AstNode* rhs = parse_shift_expr(p);
             lhs = ast_new_binary_expr(TokenKind_lt, rhs, lhs);
         } else if (op == TokenKind_ge) {
             next_token(p);
-            AstNode* rhs = parse_additive_expr(p);
+            AstNode* rhs = parse_shift_expr(p);
             lhs = ast_new_binary_expr(TokenKind_le, rhs, lhs);
         } else {
             break;
diff --git a/preprocess.c b/preprocess.c
index 776fe4b..cfc8659 100644
--- a/preprocess.c
+++ b/preprocess.c
@@ -68,6 +68,7 @@ enum TokenKind {
     TokenKind_keyword__Imaginary,
 
     TokenKind_le,
+    TokenKind_lshift,
     TokenKind_lt,
     TokenKind_literal_int,
     TokenKind_literal_str,
@@ -82,6 +83,7 @@ enum TokenKind {
     TokenKind_percent,
     TokenKind_plus,
     TokenKind_plusplus,
+    TokenKind_rshift,
     TokenKind_semicolon,
     TokenKind_slash,
     TokenKind_star,
@@ -220,6 +222,8 @@ const char* token_kind_stringify(TokenKind k) {
         return "_Imaginary";
     else if (k == TokenKind_le)
         return "le";
+    else if (k == TokenKind_lshift)
+        return "<<";
     else if (k == TokenKind_lt)
         return "lt";
     else if (k == TokenKind_literal_int)
@@ -248,6 +252,8 @@ const char* token_kind_stringify(TokenKind k) {
         return "+";
     else if (k == TokenKind_plusplus)
         return "++";
+    else if (k == TokenKind_rshift)
+        return ">>";
     else if (k == TokenKind_semicolon)
         return ";";
     else if (k == TokenKind_slash)
@@ -616,6 +622,9 @@ void pp_tokenize_all(Preprocessor* pp) {
             if (pp->src[pp->pos] == '=') {
                 ++pp->pos;
                 tok->kind = TokenKind_le;
+            } else if (pp->src[pp->pos] == '<') {
+                ++pp->pos;
+                tok->kind = TokenKind_lshift;
             } else {
                 tok->kind = TokenKind_lt;
             }
@@ -623,6 +632,9 @@ void pp_tokenize_all(Preprocessor* pp) {
             if (pp->src[pp->pos] == '=') {
                 ++pp->pos;
                 tok->kind = TokenKind_ge;
+            } else if (pp->src[pp->pos] == '>') {
+                ++pp->pos;
+                tok->kind = TokenKind_rshift;
             } else {
                 tok->kind = TokenKind_gt;
             }
diff --git a/tests/089.sh b/tests/089.sh
new file mode 100644
index 0000000..d0faca3
--- /dev/null
+++ b/tests/089.sh
@@ -0,0 +1,25 @@
+set -e
+
+cat <<'EOF' > expected
+8
+336
+EOF
+bash ../../test_diff.sh <<'EOF'
+int printf();
+int main() {
+    printf("%d\n", 1 << 3);
+    printf("%d\n", 21 << 4);
+}
+EOF
+
+cat <<'EOF' > expected
+13
+0
+EOF
+bash ../../test_diff.sh <<'EOF'
+int printf();
+int main() {
+    printf("%d\n", 111 >> 3);
+    printf("%d\n", 15 >> 14);
+}
+EOF