diff options
Diffstat (limited to 'src/codegen')
| -rw-r--r-- | src/codegen/nasm.c | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/src/codegen/nasm.c b/src/codegen/nasm.c index e55c791..2f8de80 100644 --- a/src/codegen/nasm.c +++ b/src/codegen/nasm.c @@ -203,6 +203,7 @@ static bool emit_operand(struct Emitter* emitter, struct Expr* expr) return true; } case EXPR_BINARY: + case EXPR_DEREF: return false; } @@ -248,6 +249,7 @@ static bool expr_supported(struct Emitter* emitter, struct Expr* expr) { case EXPR_PRIMARY: case EXPR_MEMBER: + case EXPR_DEREF: return true; case EXPR_BINARY: if (expr->binary.right->kind != EXPR_PRIMARY && @@ -262,8 +264,41 @@ static bool expr_supported(struct Emitter* emitter, struct Expr* expr) return false; } +// dst = [address], zero-extending narrower loads into the full register +static void emit_load(struct Emitter* emitter, const char* dst, struct DerefExpr* deref) +{ + FILE* out = emitter->out; + switch (deref->size) + { + case STORE_SIZE_BYTE: + fprintf(out, "\tmovzx %s, byte [", dst); + break; + case STORE_SIZE_WORD: + fprintf(out, "\tmovzx %s, word [", dst); + break; + case STORE_SIZE_DWORD: + { + const char* dword = sized_register(text_token(dst), STORE_SIZE_DWORD); + fprintf(out, "\tmov %s, [", dword != NULL ? dword : dst); + break; + } + default: + fprintf(out, "\tmov %s, [", dst); + break; + } + + emit_operand(emitter, deref->address); + fprintf(out, "]\n"); +} + static void emit_expr_into(struct Emitter* emitter, const char* dst, struct Expr* expr) { + if (expr->kind == EXPR_DEREF) + { + emit_load(emitter, dst, &expr->deref); + return; + } + if (expr->kind == EXPR_BINARY) { emit_expr_into(emitter, dst, expr->binary.left); @@ -389,7 +424,8 @@ static void emit_assign(struct Emitter* emitter, struct AssignStatement* assign) const char* mnemonic = assign_mnemonic(assign->op.type); bool value_is_buffer = assign->value->kind == EXPR_PRIMARY && is_buffer_name(emitter, assign->value->primary.token); - if (mnemonic == NULL || assign->value->kind == EXPR_BINARY || value_is_buffer) + if (mnemonic == NULL || assign->value->kind == EXPR_BINARY + || assign->value->kind == EXPR_DEREF || value_is_buffer) { fprintf(emitter->out, "\t; TODO: unsupported assignment\n"); return; @@ -458,7 +494,7 @@ static void emit_call(struct Emitter* emitter, struct CallStatement* call) for (size_t i = 0; i < call->arg_count; i += 1) { - if (call->args[i]->kind == EXPR_BINARY) + if (call->args[i]->kind == EXPR_BINARY || call->args[i]->kind == EXPR_DEREF) { fprintf(emitter->out, "\t; TODO: unsupported call argument\n"); continue; @@ -478,7 +514,9 @@ static void emit_statement(struct Emitter* emitter, struct Statement* statement) static void emit_if(struct Emitter* emitter, struct IfStatement* branch) { const char* jump = jump_if_false(branch->comparison.type); - if (jump == NULL || branch->left->kind == EXPR_BINARY || branch->right->kind == EXPR_BINARY) + if (jump == NULL + || branch->left->kind == EXPR_BINARY || branch->left->kind == EXPR_DEREF + || branch->right->kind == EXPR_BINARY || branch->right->kind == EXPR_DEREF) { fprintf(emitter->out, "\t; TODO: unsupported if\n"); return; |