diff options
| -rw-r--r-- | codegen.c | 77 | ||||
| -rw-r--r-- | tests/072.sh | 87 |
2 files changed, 148 insertions, 16 deletions
@@ -87,22 +87,39 @@ void codegen_ref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) { codegen_expr(g, ast->node_operand, GenMode_lval); } +// "reg" stores the address of the expression to be pushed. +void codegen_push_expr(const char* reg, int size) { + if (size == 1) { + printf(" movsx %s, BYTE PTR [%s]\n", reg, reg); + printf(" push %s\n", reg); + } else if (size == 2) { + unimplemented(); + } else if (size == 4) { + printf(" movsxd %s, DWORD PTR [%s]\n", reg, reg); + printf(" push %s\n", reg); + } else if (size == 8) { + printf(" mov %s, [%s]\n", reg, reg); + printf(" push %s\n", reg); + } else { + // Perform bitwise copy. Use r10 register as temporary space. + // Note: rsp must be aligned to 8. + printf(" sub rsp, %d\n", to_aligned(size, 8)); + int i; + for (i = 0; i < size; ++i) { + // Copy a sinle byte from the address that "reg" points to to the stack via r10 register. + printf(" mov r10b, [%s+%d]\n", reg, i); + printf(" mov [rsp+%d], r10b\n", i); + } + } +} + void codegen_lval2rval(Type* ty) { if (ty->kind == TypeKind_array) { return; } - int size = type_sizeof(ty); - printf(" pop rax\n"); - if (size == 1) { - printf(" movsx rax, BYTE PTR [rax]\n"); - } else if (size == 4) { - printf(" movsxd rax, DWORD PTR [rax]\n"); - } else { - printf(" mov rax, [rax]\n"); - } - printf(" push rax\n"); + codegen_push_expr("rax", type_sizeof(ty)); } void codegen_deref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) { @@ -181,6 +198,9 @@ void codegen_binary_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) { } void codegen_assign_expr(CodeGen* g, AstNode* ast) { + int sizeof_lhs = type_sizeof(ast->node_lhs->ty); + int sizeof_rhs = type_sizeof(ast->node_rhs->ty); + codegen_expr(g, ast->node_lhs, GenMode_lval); codegen_expr(g, ast->node_rhs, GenMode_rval); if (ast->node_op == TokenKind_assign) { @@ -201,16 +221,40 @@ void codegen_assign_expr(CodeGen* g, AstNode* ast) { } else { unreachable(); } - printf(" pop rdi\n"); - printf(" pop rax\n"); - if (type_sizeof(ast->node_lhs->ty) == 1) { + if (sizeof_lhs == 1) { + printf(" pop rdi\n"); + printf(" pop rax\n"); printf(" mov BYTE PTR [rax], dil\n"); - } else if (type_sizeof(ast->node_lhs->ty) == 4) { + printf(" push rdi\n"); + } else if (sizeof_lhs == 4) { + printf(" pop rdi\n"); + printf(" pop rax\n"); printf(" mov DWORD PTR [rax], edi\n"); - } else { + printf(" push rdi\n"); + } else if (sizeof_lhs == 8) { + printf(" pop rdi\n"); + printf(" pop rax\n"); printf(" mov [rax], rdi\n"); + printf(" push rdi\n"); + } else { + if (ast->node_op != TokenKind_assign) { + unimplemented(); + } + // Note: rsp must be aligned to 8. + int aligned_size = to_aligned(sizeof_lhs, 8); + printf(" mov rax, [rsp+%d]\n", aligned_size); + // Perform bitwise copy. Use r10 register as temporary space. + int i; + for (i = 0; i < aligned_size; ++i) { + // Copy a sinle byte from the stack to the address that rax points to via r10 register. + printf(" mov r10b, [rsp+%d]\n", i); + printf(" mov [rax+%d], r10b\n", i); + } + // Pop the RHS value and the LHS address. + printf(" add rsp, %d\n", aligned_size + 8); + // TODO: dummy + printf(" push 0\n"); } - printf(" push rdi\n"); } void codegen_func_call(CodeGen* g, AstNode* ast) { @@ -399,6 +443,7 @@ void codegen_continue_stmt(CodeGen* g, AstNode* ast) { void codegen_expr_stmt(CodeGen* g, AstNode* ast) { codegen_expr(g, ast->node_expr, GenMode_rval); + // TODO: the expression on the stack can be more than 8 bytes. printf(" pop rax\n"); } diff --git a/tests/072.sh b/tests/072.sh new file mode 100644 index 0000000..9e7ab9b --- /dev/null +++ b/tests/072.sh @@ -0,0 +1,87 @@ +set -e + +cat <<'EOF' > expected +123 456 +0 0 +123 456 +EOF + +bash ../../test_diff.sh <<'EOF' +struct S { + int a; + int b; +}; +typedef struct S S; + +void* calloc(); +int printf(); + +int main() { + S* s1 = calloc(1, sizeof(S)); + S* s2 = calloc(1, sizeof(S)); + s1->a = 123; + s1->b = 456; + printf("%d %d\n", s1->a, s1->b); + printf("%d %d\n", s2->a, s2->b); + *s2 = *s1; + printf("%d %d\n", s2->a, s2->b); +} +EOF + +cat <<'EOF' > expected +123 456 +0 0 +123 456 +EOF + +bash ../../test_diff.sh <<'EOF' +struct S { + long a; + long b; +}; +typedef struct S S; + +void* calloc(); +int printf(); + +int main() { + S* s1 = calloc(1, sizeof(S)); + S* s2 = calloc(1, sizeof(S)); + s1->a = 123; + s1->b = 456; + printf("%d %d\n", s1->a, s1->b); + printf("%d %d\n", s2->a, s2->b); + *s2 = *s1; + printf("%d %d\n", s2->a, s2->b); +} +EOF + +cat <<'EOF' > expected +123 456 +0 0 +123 456 +EOF + +bash ../../test_diff.sh <<'EOF' +struct S { + long a; + long b; +}; +typedef struct S S; + +void* calloc(); +int printf(); + +int main() { + S s1; + S s2; + s1.a = 123; + s1.b = 456; + s2.a = 0; + s2.b = 0; + printf("%d %d\n", s1.a, s1.b); + printf("%d %d\n", s2.a, s2.b); + s2 = s1; + printf("%d %d\n", s2.a, s2.b); +} +EOF |