1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_RUNTIME_ARCH_X86_ASM_SUPPORT_X86_S_
18#define ART_RUNTIME_ARCH_X86_ASM_SUPPORT_X86_S_
19
20#include "asm_support_x86.h"
21#include "interpreter/cfi_asm_support.h"
22
23// Regular gas(1) & current clang/llvm assembler support named macro parameters.
24#define MACRO0(macro_name) .macro macro_name
25#define MACRO1(macro_name, macro_arg1) .macro macro_name macro_arg1
26#define MACRO2(macro_name, macro_arg1, macro_arg2) .macro macro_name macro_arg1, macro_arg2
27#define MACRO3(macro_name, macro_arg1, macro_arg2, macro_arg3) .macro macro_name macro_arg1, macro_arg2, macro_arg3
28#define MACRO4(macro_name, macro_arg1, macro_arg2, macro_arg3, macro_arg4) .macro macro_name macro_arg1, macro_arg2, macro_arg3, macro_arg4
29#define MACRO5(macro_name, macro_arg1, macro_arg2, macro_arg3, macro_arg4, macro_arg5) .macro macro_name macro_arg1, macro_arg2, macro_arg3, macro_arg4, macro_arg5
30#define END_MACRO .endm
31
32#if defined(__clang__)
33    // Clang/llvm does not support .altmacro. However, the clang/llvm preprocessor doesn't
34    // separate the backslash and parameter by a space. Everything just works.
35    #define RAW_VAR(name) \name
36    #define VAR(name) \name
37    #define CALLVAR(name) SYMBOL(\name)
38    #define PLT_VAR(name) \name@PLT
39    #define REG_VAR(name) %\name
40    #define CALL_MACRO(name) \name
41#else
42    // Regular gas(1) uses \argument_name for macro arguments.
43    // We need to turn on alternate macro syntax so we can use & instead or the preprocessor
44    // will screw us by inserting a space between the \ and the name. Even in this mode there's
45    // no special meaning to $, so literals are still just $x. The use of altmacro means % is a
46    // special character meaning care needs to be taken when passing registers as macro
47    // arguments.
48    .altmacro
49    #define RAW_VAR(name) name&
50    #define VAR(name) name&
51    #define CALLVAR(name) SYMBOL(name&)
52    #define PLT_VAR(name) name&@PLT
53    #define REG_VAR(name) %name
54    #define CALL_MACRO(name) name&
55#endif
56
57#define LITERAL(value) $value
58#if defined(__APPLE__)
59    #define MACRO_LITERAL(value) $(value)
60#else
61    #define MACRO_LITERAL(value) $value
62#endif
63
64#if defined(__APPLE__)
65    #define FUNCTION_TYPE(name)
66    #define SIZE(name)
67#else
68    #define FUNCTION_TYPE(name) .type name, @function
69    #define SIZE(name) .size name, .-name
70#endif
71
72    // CFI support.
73#if !defined(__APPLE__)
74    #define CFI_STARTPROC .cfi_startproc
75    #define CFI_ENDPROC .cfi_endproc
76    #define CFI_ADJUST_CFA_OFFSET(size) .cfi_adjust_cfa_offset size
77    #define CFI_DEF_CFA(reg,size) .cfi_def_cfa reg,size
78    #define CFI_DEF_CFA_REGISTER(reg) .cfi_def_cfa_register reg
79    #define CFI_RESTORE(reg) .cfi_restore reg
80    #define CFI_REL_OFFSET(reg,size) .cfi_rel_offset reg,size
81    #define CFI_REGISTER(orig_reg, current_reg) .cfi_register orig_reg, current_reg
82    #define CFI_REMEMBER_STATE .cfi_remember_state
83    // The spec is not clear whether the CFA is part of the saved state and tools
84    // differ in the behaviour, so explicitly set the CFA to avoid any ambiguity.
85    // The restored CFA state should match the CFA state during CFI_REMEMBER_STATE.
86    // `objdump -Wf libart.so | egrep "_cfa|_state"` is useful to audit the opcodes.
87    #define CFI_RESTORE_STATE_AND_DEF_CFA(reg,off) .cfi_restore_state .cfi_def_cfa reg,off
88    #define CFI_ESCAPE(...) .cfi_escape __VA_ARGS__
89#else
90    // Mac OS' doesn't like cfi_* directives.
91    #define CFI_STARTPROC
92    #define CFI_ENDPROC
93    #define CFI_ADJUST_CFA_OFFSET(size)
94    #define CFI_DEF_CFA(reg,size)
95    #define CFI_DEF_CFA_REGISTER(reg)
96    #define CFI_RESTORE(reg)
97    #define CFI_REL_OFFSET(reg,size)
98    #define CFI_REGISTER(orig_reg, current_reg)
99    #define CFI_REMEMBER_STATE
100    #define CFI_RESTORE_STATE_AND_DEF_CFA(reg,off)
101    #define CFI_ESCAPE(...)
102#endif
103
104#define CFI_REG_eax 0
105#define CFI_REG_ecx 1
106#define CFI_REG_edx 2
107#define CFI_REG_ebx 3
108#define CFI_REG_esp 4
109#define CFI_REG_ebp 5
110#define CFI_REG_esi 6
111#define CFI_REG_edi 7
112#define CFI_REG_eip 8
113
114#define CFI_REG(reg) CFI_REG_##reg
115
116MACRO3(CFI_EXPRESSION_BREG, n, b, offset)
117    .if (-0x40 <= (\offset)) && ((\offset) < 0x40)
118        CFI_EXPRESSION_BREG_1(\n, \b, \offset)
119    .elseif (-0x2000 <= (\offset)) && ((\offset) < 0x2000)
120        CFI_EXPRESSION_BREG_2(\n, \b, \offset)
121    .else
122        .error "Unsupported offset"
123    .endif
124END_MACRO
125
126    // Symbols. On a Mac, we need a leading underscore.
127#if !defined(__APPLE__)
128    #define SYMBOL(name) name
129    #define PLT_SYMBOL(name) name ## @PLT
130#else
131    // Mac OS' symbols have an _ prefix.
132    #define SYMBOL(name) _ ## name
133    #define PLT_SYMBOL(name) _ ## name
134#endif
135
136// Directive to hide a function symbol.
137#if defined(__APPLE__)
138    #define ASM_HIDDEN .private_extern
139#else
140    #define ASM_HIDDEN .hidden
141#endif
142
143    /* Cache alignment for function entry */
144MACRO0(ALIGN_FUNCTION_ENTRY)
145    // ART-compiled functions have OatQuickMethodHeader but assembly funtions do not.
146    // Prefix the assembly code with 0xFFs, which means there is no method header.
147    .byte 0xFF, 0xFF, 0xFF, 0xFF
148    // Cache alignment for function entry.
149    .balign 16, 0xFF
150END_MACRO
151
152MACRO2(DEFINE_FUNCTION_CUSTOM_CFA, c_name, cfa_offset)
153    FUNCTION_TYPE(SYMBOL(\c_name))
154    ASM_HIDDEN CALLVAR(c_name)
155    .globl CALLVAR(c_name)
156    ALIGN_FUNCTION_ENTRY
157CALLVAR(c_name):
158    CFI_STARTPROC
159    // Ensure we get an appropriate starting CFA.
160    CFI_DEF_CFA(esp, RAW_VAR(cfa_offset))
161END_MACRO
162
163MACRO1(DEFINE_FUNCTION, c_name)
164    DEFINE_FUNCTION_CUSTOM_CFA RAW_VAR(c_name), __SIZEOF_POINTER__
165END_MACRO
166
167MACRO1(END_FUNCTION, c_name)
168    CFI_ENDPROC
169    SIZE(SYMBOL(\c_name))
170END_MACRO
171
172MACRO1(PUSH, reg)
173    pushl REG_VAR(reg)
174    CFI_ADJUST_CFA_OFFSET(4)
175    CFI_REL_OFFSET(REG_VAR(reg), 0)
176END_MACRO
177
178MACRO1(POP, reg)
179    popl REG_VAR(reg)
180    CFI_ADJUST_CFA_OFFSET(-4)
181    CFI_RESTORE(REG_VAR(reg))
182END_MACRO
183
184// Arguments do not need .cfi_rel_offset as they are caller-saved and
185// therefore cannot hold caller's variables or unwinding data.
186MACRO1(PUSH_ARG, reg)
187    pushl REG_VAR(reg)
188    CFI_ADJUST_CFA_OFFSET(4)
189END_MACRO
190
191MACRO1(POP_ARG, reg)
192    popl REG_VAR(reg)
193    CFI_ADJUST_CFA_OFFSET(-4)
194END_MACRO
195
196MACRO1(CFI_RESTORE_REG, reg)
197    CFI_RESTORE(REG_VAR(reg))
198END_MACRO
199
200MACRO1(INCREASE_FRAME, frame_adjustment)
201    subl MACRO_LITERAL(RAW_VAR(frame_adjustment)), %esp
202    CFI_ADJUST_CFA_OFFSET((RAW_VAR(frame_adjustment)))
203END_MACRO
204
205MACRO1(DECREASE_FRAME, frame_adjustment)
206    addl MACRO_LITERAL(RAW_VAR(frame_adjustment)), %esp
207    CFI_ADJUST_CFA_OFFSET(-(RAW_VAR(frame_adjustment)))
208END_MACRO
209
210#define UNREACHABLE int3
211
212MACRO1(UNIMPLEMENTED,name)
213    FUNCTION_TYPE(\name)
214    .globl VAR(name)
215    ALIGN_FUNCTION_ENTRY
216VAR(name):
217    CFI_STARTPROC
218    UNREACHABLE
219    UNREACHABLE
220    CFI_ENDPROC
221    SIZE(\name)
222END_MACRO
223
224MACRO1(SETUP_GOT_NOSAVE, got_reg)
225#ifndef __APPLE__
226    .ifc VAR(got_reg), ebx
227      call __x86.get_pc_thunk.bx
228      addl $_GLOBAL_OFFSET_TABLE_, %ebx
229    .else
230      .error "Unknown GOT register \got_reg"
231    .endif
232#endif
233END_MACRO
234
235MACRO2(LOAD_RUNTIME_INSTANCE, reg, got_reg)
236    SETUP_GOT_NOSAVE \got_reg
237    // Load Runtime::instance_ from GOT.
238    movl SYMBOL(_ZN3art7Runtime9instance_E)@GOT(REG_VAR(got_reg)), REG_VAR(reg)
239    movl (REG_VAR(reg)), REG_VAR(reg)
240END_MACRO
241
242// Macros to poison (negate) the reference for heap poisoning.
243MACRO1(POISON_HEAP_REF, rRef)
244#ifdef USE_HEAP_POISONING
245    neg REG_VAR(rRef)
246#endif  // USE_HEAP_POISONING
247END_MACRO
248
249// Macros to unpoison (negate) the reference for heap poisoning.
250MACRO1(UNPOISON_HEAP_REF, rRef)
251#ifdef USE_HEAP_POISONING
252    neg REG_VAR(rRef)
253#endif  // USE_HEAP_POISONING
254END_MACRO
255
256    /*
257     * Macro that sets up the callee save frame to conform with
258     * Runtime::CreateCalleeSaveMethod(kSaveRefsAndArgs), except for pushing the method
259     */
260MACRO0(SETUP_SAVE_REFS_AND_ARGS_FRAME_REGISTERS_ONLY)
261    PUSH edi      // Save callee saves
262    PUSH esi
263    PUSH ebp
264    PUSH_ARG ebx  // Save args.
265    PUSH_ARG edx
266    PUSH_ARG ecx
267    // Create space for FPR args.
268    INCREASE_FRAME 4 * 8
269    // Save FPRs.
270    movsd %xmm0, 0(%esp)
271    movsd %xmm1, 8(%esp)
272    movsd %xmm2, 16(%esp)
273    movsd %xmm3, 24(%esp)
274
275    // Ugly compile-time check, but we only have the preprocessor.
276    // First +4: implicit return address pushed on stack when caller made call.
277    // Last +4: we're not pushing the method on the stack here.
278#if (FRAME_SIZE_SAVE_REFS_AND_ARGS != 4 + 6*4 + 4*8 + 4)
279#error "FRAME_SIZE_SAVE_REFS_AND_ARGS(X86) size not as expected."
280#endif
281END_MACRO
282
283MACRO0(RESTORE_SAVE_REFS_AND_ARGS_FRAME)
284    // Restore FPRs. EAX is still on the stack.
285    movsd 4(%esp), %xmm0
286    movsd 12(%esp), %xmm1
287    movsd 20(%esp), %xmm2
288    movsd 28(%esp), %xmm3
289
290    DECREASE_FRAME 36             // Remove FPRs and method pointer.
291
292    POP_ARG ecx                   // Restore args
293    POP_ARG edx
294    POP_ARG ebx
295    POP ebp                       // Restore callee saves
296    POP esi
297    POP edi
298END_MACRO
299
300    /*
301     * Macro that calls through to artDeliverPendingExceptionFromCode, where the pending
302     * exception is Thread::Current()->exception_ when the runtime method frame is ready.
303     */
304MACRO0(DELIVER_PENDING_EXCEPTION_FRAME_READY)
305    // Outgoing argument set up
306    INCREASE_FRAME 12                          // alignment padding
307    pushl %fs:THREAD_SELF_OFFSET               // pass Thread::Current()
308    CFI_ADJUST_CFA_OFFSET(4)
309    call SYMBOL(artDeliverPendingExceptionFromCode)  // artDeliverPendingExceptionFromCode(Thread*)
310    UNREACHABLE
311    CFI_ADJUST_CFA_OFFSET(-16)                 // Reset CFA in case there is more code afterwards.
312END_MACRO
313
314#endif  // ART_RUNTIME_ARCH_X86_ASM_SUPPORT_X86_S_
315