logical or

LesleyLai · Jan 10, 2025 · ca2ea99 · ca2ea99
1 parent 001ec83
commit ca2ea99
Show file tree

Hide file tree

Showing 12 changed files with 138 additions and 42 deletions.
diff --git a/include/mcc/ir.h b/include/mcc/ir.h
@@ -70,6 +70,7 @@ typedef enum IRInstructionType {
   IR_JMP,
   // conditional jump
   // br <cond> <if_label> <else_label>
+  // jump to <if_label> if <cond> is not zero, otherwise jump to <else_label>
   IR_BR,
 
   IR_LABEL,

diff --git a/src/ir/ir_generator.c b/src/ir/ir_generator.c
@@ -153,6 +153,92 @@ static IRValue emit_ir_instructions_from_binary_expr(const Expr* expr,
   return dst;
 }
 
+static IRValue emit_ir_instructions_from_logical_and(const Expr* expr,
+                                                     IRGenContext* context)
+{
+  const IRValue lhs =
+      emit_ir_instructions_from_expr(expr->binary_op.lhs, context);
+  const StringView lhs_true_label =
+      create_fresh_label_name(context, "and_lhs_true");
+  const StringView rhs_true_label =
+      create_fresh_label_name(context, "and_rhs_true");
+  const StringView false_label = create_fresh_label_name(context, "and_false");
+  const StringView end_label = create_fresh_label_name(context, "and_end");
+
+  const IRValue result = ir_variable(string_view_from_c_str("result"));
+
+  // br lhs .and_lhs_true .and_false
+  push_instruction(context, ir_br(lhs, lhs_true_label, false_label));
+  // .and_lhs_true:
+  push_instruction(context, ir_label(lhs_true_label));
+
+  const IRValue rhs =
+      emit_ir_instructions_from_expr(expr->binary_op.rhs, context);
+
+  // br rhs .and_rhs_true .and_false
+  push_instruction(context, ir_br(rhs, rhs_true_label, false_label));
+
+  // .and_rhs_true:
+  // result = 1
+  // jmp .and_end
+  push_instruction(context, ir_label(rhs_true_label));
+  push_instruction(context, ir_unary_instr(IR_COPY, result, ir_constant(1)));
+  push_instruction(context, ir_jmp(end_label));
+
+  // .and_false:
+  // result = 0
+  push_instruction(context, ir_label(false_label));
+  push_instruction(context, ir_unary_instr(IR_COPY, result, ir_constant(0)));
+
+  // .and_end
+  push_instruction(context, ir_label(end_label));
+
+  return result;
+}
+
+static IRValue emit_ir_instructions_from_logical_or(const Expr* expr,
+                                                    IRGenContext* context)
+{
+  const IRValue lhs =
+      emit_ir_instructions_from_expr(expr->binary_op.lhs, context);
+  const StringView lhs_false_label =
+      create_fresh_label_name(context, "or_lhs_false");
+  const StringView rhs_false_label =
+      create_fresh_label_name(context, "or_rhs_false");
+  const StringView true_label = create_fresh_label_name(context, "or_true");
+  const StringView end_label = create_fresh_label_name(context, "or_end");
+
+  const IRValue result = ir_variable(string_view_from_c_str("result"));
+
+  // br lhs .or_true .or_lhs_false
+  push_instruction(context, ir_br(lhs, true_label, lhs_false_label));
+  // .or_lhs_false:
+  push_instruction(context, ir_label(lhs_false_label));
+
+  const IRValue rhs =
+      emit_ir_instructions_from_expr(expr->binary_op.rhs, context);
+
+  // br rhs .or_true .or_rhs_false
+  push_instruction(context, ir_br(rhs, true_label, rhs_false_label));
+
+  // .or_rhs_false:
+  // result = 0
+  // jmp .or_end
+  push_instruction(context, ir_label(rhs_false_label));
+  push_instruction(context, ir_unary_instr(IR_COPY, result, ir_constant(0)));
+  push_instruction(context, ir_jmp(end_label));
+
+  // .or_true:
+  // result = 1
+  push_instruction(context, ir_label(true_label));
+  push_instruction(context, ir_unary_instr(IR_COPY, result, ir_constant(1)));
+
+  // .or_end:
+  push_instruction(context, ir_label(end_label));
+
+  return result;
+}
+
 static IRValue emit_ir_instructions_from_expr(const Expr* expr,
                                               IRGenContext* context)
 {
@@ -177,45 +263,10 @@ static IRValue emit_ir_instructions_from_expr(const Expr* expr,
   }
   case EXPR_BINARY: {
     switch (expr->binary_op.binary_op_type) {
-    case BINARY_OP_AND: {
-      const IRValue lhs =
-          emit_ir_instructions_from_expr(expr->binary_op.lhs, context);
-      const StringView lhs_true_label =
-          create_fresh_label_name(context, "and_lhs_true");
-      const StringView rhs_true_label =
-          create_fresh_label_name(context, "and_rhs_true");
-      const StringView false_label =
-          create_fresh_label_name(context, "and_false");
-      const StringView end_label = create_fresh_label_name(context, "and_end");
-
-      const IRValue result = ir_variable(string_view_from_c_str("result"));
-
-      push_instruction(context, ir_br(lhs, lhs_true_label, false_label));
-      push_instruction(context, ir_label(lhs_true_label));
-
-      const IRValue rhs =
-          emit_ir_instructions_from_expr(expr->binary_op.rhs, context);
-
-      push_instruction(context, ir_br(rhs, rhs_true_label, false_label));
-
-      // .if2:
-      // result = 1
-      push_instruction(context, ir_label(rhs_true_label));
-      push_instruction(context,
-                       ir_unary_instr(IR_COPY, result, ir_constant(1)));
-      push_instruction(context, ir_jmp(end_label));
-
-      // .false
-      push_instruction(context, ir_label(false_label));
-      // result = 0
-      push_instruction(context,
-                       ir_unary_instr(IR_COPY, result, ir_constant(0)));
-
-      push_instruction(context, ir_label(end_label));
-
-      return result;
-    }
-    case BINARY_OP_OR: MCC_UNIMPLEMENTED();
+    case BINARY_OP_AND:
+      return emit_ir_instructions_from_logical_and(expr, context);
+    case BINARY_OP_OR:
+      return emit_ir_instructions_from_logical_or(expr, context);
     default: return emit_ir_instructions_from_binary_expr(expr, context);
     }
   }

diff --git a/src/x86/x86_from_ir.c b/src/x86/x86_from_ir.c
@@ -222,8 +222,21 @@ X86FunctionDef x86_function_from_ir(const IRFunctionDef* ir_function,
                                             }});
 
           break;
+          // If the else_label is directly follow this instruction
         } else if (string_view_eq(next_instruction->label, else_label)) {
-          MCC_UNIMPLEMENTED();
+          // cmp cond, 0
+          push_instruction(&instructions,
+                           binary_instruction(X86_INST_CMP, X86_SZ_4, cond,
+                                              immediate_operand(0)));
+          // jne .if_label
+          push_instruction(&instructions,
+                           (X86Instruction){.typ = X86_INST_JMPCC,
+                                            .jmpcc = {
+                                                .cond = X86_COND_NE,
+                                                .label = if_label,
+                                            }});
+
+          break;
         }
       }
 

diff --git a/test/test_data/basics/logical/and_false.c b/test/test_data/basics/logical/and_false.c
@@ -1,5 +1,5 @@
 // RETURN: 0
 int main(void)
 {
-  return (-1 && 0) + (0 && 42);
+  return (-1 && 0) + (0 && 42) + (0 && 0);
 }
diff --git a/test/test_data/basics/logical/and.c → test/test_data/basics/logical/and_true.c b/test/test_data/basics/logical/and.c → test/test_data/basics/logical/and_true.c
diff --git a/test/test_data/basics/logical/multi_short_circuit.c b/test/test_data/basics/logical/multi_short_circuit.c
@@ -0,0 +1,5 @@
+// RETURN: 0
+int main(void)
+{
+  return 0 || 0 && (1 / 0);
+}
diff --git a/test/test_data/basics/logical/or_false.c b/test/test_data/basics/logical/or_false.c
@@ -0,0 +1,5 @@
+// RETURN: 0
+int main(void)
+{
+  return 0 || 0;
+}
diff --git a/test/test_data/basics/logical/or_short_circuit.c b/test/test_data/basics/logical/or_short_circuit.c
@@ -0,0 +1,5 @@
+// RETURN: 1
+int main(void)
+{
+  return 1 || (1 / 0);
+}
diff --git a/test/test_data/basics/logical/or_true.c b/test/test_data/basics/logical/or_true.c
@@ -0,0 +1,5 @@
+// RETURN: 3
+int main(void)
+{
+  return (1 || 0) + (2 || 3) + (0 || 4);
+}
diff --git a/test/test_data/basics/logical/precedence.c b/test/test_data/basics/logical/precedence.c
@@ -0,0 +1,5 @@
+// RETURN: 1
+int main(void)
+{
+  return 1 || 0 && 2;
+}
diff --git a/test/test_data/basics/logical/precedence2.c b/test/test_data/basics/logical/precedence2.c
@@ -0,0 +1,5 @@
+// RETURN: 1
+int main(void)
+{
+  return 2 == 2 || 0;
+}
diff --git a/test/unit_tests/CMakeLists.txt b/test/unit_tests/CMakeLists.txt
@@ -8,7 +8,8 @@ add_executable(mcc_unit_tests
         string_test.cpp
         formatting_test.cpp
         lexer_test.cpp
-        dynarray_test.cpp)
+        dynarray_test.cpp
+)
 target_link_libraries(mcc_unit_tests PUBLIC mcc_lib mcc::compiler_warnings Catch2::Catch2WithMain fmt::fmt)
 
 add_test(NAME mcc COMMAND mcc_unit_tests)