91 //
92 // Generates code that causes a NULL OS exception if the content of reg is NULL.
93 // If the accessed location is M[reg + offset] and the offset is known, provide the
94 // offset. No explicit code generation is needed if the offset is within a certain
95 // range (0 <= offset <= page_size).
96
97 void null_check(Register reg, int offset = -1);
98 static bool needs_explicit_null_check(intptr_t offset);
99
100 void test_klass_is_value(Register klass, Register temp_reg, Label& is_value);
101
102 void test_field_is_flattenable(Register flags, Register temp_reg, Label& is_flattenable);
103 void test_field_is_not_flattenable(Register flags, Register temp_reg, Label& notFlattenable);
104 void test_field_is_flattened(Register flags, Register temp_reg, Label& is_flattened);
105 void test_value_is_not_buffered(Register value, Register temp_reg, Label& not_buffered);
106
107 // Check klass/oops is flat value type array (oop->_klass->_layout_helper & vt_bit)
108 void test_flat_array_klass(Register klass, Register temp_reg, Label& is_flat_array);
109 void test_flat_array_oop(Register oop, Register temp_reg, Label& is_flat_array);
110
111 // Required platform-specific helpers for Label::patch_instructions.
112 // They _shadow_ the declarations in AbstractAssembler, which are undefined.
113 void pd_patch_instruction(address branch, address target) {
114 unsigned char op = branch[0];
115 assert(op == 0xE8 /* call */ ||
116 op == 0xE9 /* jmp */ ||
117 op == 0xEB /* short jmp */ ||
118 (op & 0xF0) == 0x70 /* short jcc */ ||
119 op == 0x0F && (branch[1] & 0xF0) == 0x80 /* jcc */ ||
120 op == 0xC7 && branch[1] == 0xF8 /* xbegin */,
121 "Invalid opcode at patch point");
122
123 if (op == 0xEB || (op & 0xF0) == 0x70) {
124 // short offset operators (jmp and jcc)
125 char* disp = (char*) &branch[1];
126 int imm8 = target - (address) &disp[1];
127 guarantee(this->is8bit(imm8), "Short forward jump exceeds 8-bit offset");
128 *disp = imm8;
129 } else {
130 int* disp = (int*) &branch[(op == 0x0F || op == 0xC7)? 2: 1];
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91 //
92 // Generates code that causes a NULL OS exception if the content of reg is NULL.
93 // If the accessed location is M[reg + offset] and the offset is known, provide the
94 // offset. No explicit code generation is needed if the offset is within a certain
95 // range (0 <= offset <= page_size).
96
97 void null_check(Register reg, int offset = -1);
98 static bool needs_explicit_null_check(intptr_t offset);
99
100 void test_klass_is_value(Register klass, Register temp_reg, Label& is_value);
101
102 void test_field_is_flattenable(Register flags, Register temp_reg, Label& is_flattenable);
103 void test_field_is_not_flattenable(Register flags, Register temp_reg, Label& notFlattenable);
104 void test_field_is_flattened(Register flags, Register temp_reg, Label& is_flattened);
105 void test_value_is_not_buffered(Register value, Register temp_reg, Label& not_buffered);
106
107 // Check klass/oops is flat value type array (oop->_klass->_layout_helper & vt_bit)
108 void test_flat_array_klass(Register klass, Register temp_reg, Label& is_flat_array);
109 void test_flat_array_oop(Register oop, Register temp_reg, Label& is_flat_array);
110
111 void test_oop_is_value(Register oop, Register temp, Label* is_value, Label* is_not_value);
112
113 // Required platform-specific helpers for Label::patch_instructions.
114 // They _shadow_ the declarations in AbstractAssembler, which are undefined.
115 void pd_patch_instruction(address branch, address target) {
116 unsigned char op = branch[0];
117 assert(op == 0xE8 /* call */ ||
118 op == 0xE9 /* jmp */ ||
119 op == 0xEB /* short jmp */ ||
120 (op & 0xF0) == 0x70 /* short jcc */ ||
121 op == 0x0F && (branch[1] & 0xF0) == 0x80 /* jcc */ ||
122 op == 0xC7 && branch[1] == 0xF8 /* xbegin */,
123 "Invalid opcode at patch point");
124
125 if (op == 0xEB || (op & 0xF0) == 0x70) {
126 // short offset operators (jmp and jcc)
127 char* disp = (char*) &branch[1];
128 int imm8 = target - (address) &disp[1];
129 guarantee(this->is8bit(imm8), "Short forward jump exceeds 8-bit offset");
130 *disp = imm8;
131 } else {
132 int* disp = (int*) &branch[(op == 0x0F || op == 0xC7)? 2: 1];
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