github.com/twelsh-aw/go/src@v0.0.0-20230516233729-a56fe86a7c81/runtime/asm_amd64.s (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "go_asm.h"
     6  #include "go_tls.h"
     7  #include "funcdata.h"
     8  #include "textflag.h"
     9  #include "cgo/abi_amd64.h"
    10  
    11  // _rt0_amd64 is common startup code for most amd64 systems when using
    12  // internal linking. This is the entry point for the program from the
    13  // kernel for an ordinary -buildmode=exe program. The stack holds the
    14  // number of arguments and the C-style argv.
    15  TEXT _rt0_amd64(SB),NOSPLIT,$-8
    16  	MOVQ	0(SP), DI	// argc
    17  	LEAQ	8(SP), SI	// argv
    18  	JMP	runtime·rt0_go(SB)
    19  
    20  // main is common startup code for most amd64 systems when using
    21  // external linking. The C startup code will call the symbol "main"
    22  // passing argc and argv in the usual C ABI registers DI and SI.
    23  TEXT main(SB),NOSPLIT,$-8
    24  	JMP	runtime·rt0_go(SB)
    25  
    26  // _rt0_amd64_lib is common startup code for most amd64 systems when
    27  // using -buildmode=c-archive or -buildmode=c-shared. The linker will
    28  // arrange to invoke this function as a global constructor (for
    29  // c-archive) or when the shared library is loaded (for c-shared).
    30  // We expect argc and argv to be passed in the usual C ABI registers
    31  // DI and SI.
    32  TEXT _rt0_amd64_lib(SB),NOSPLIT|NOFRAME,$0
    33  	// Transition from C ABI to Go ABI.
    34  	PUSH_REGS_HOST_TO_ABI0()
    35  
    36  	MOVQ	DI, _rt0_amd64_lib_argc<>(SB)
    37  	MOVQ	SI, _rt0_amd64_lib_argv<>(SB)
    38  
    39  	// Synchronous initialization.
    40  	CALL	runtime·libpreinit(SB)
    41  
    42  	// Create a new thread to finish Go runtime initialization.
    43  	MOVQ	_cgo_sys_thread_create(SB), AX
    44  	TESTQ	AX, AX
    45  	JZ	nocgo
    46  
    47  	// We're calling back to C.
    48  	// Align stack per ELF ABI requirements.
    49  	MOVQ	SP, BX  // Callee-save in C ABI
    50  	ANDQ	$~15, SP
    51  	MOVQ	$_rt0_amd64_lib_go(SB), DI
    52  	MOVQ	$0, SI
    53  	CALL	AX
    54  	MOVQ	BX, SP
    55  	JMP	restore
    56  
    57  nocgo:
    58  	ADJSP	$16
    59  	MOVQ	$0x800000, 0(SP)		// stacksize
    60  	MOVQ	$_rt0_amd64_lib_go(SB), AX
    61  	MOVQ	AX, 8(SP)			// fn
    62  	CALL	runtime·newosproc0(SB)
    63  	ADJSP	$-16
    64  
    65  restore:
    66  	POP_REGS_HOST_TO_ABI0()
    67  	RET
    68  
    69  // _rt0_amd64_lib_go initializes the Go runtime.
    70  // This is started in a separate thread by _rt0_amd64_lib.
    71  TEXT _rt0_amd64_lib_go(SB),NOSPLIT,$0
    72  	MOVQ	_rt0_amd64_lib_argc<>(SB), DI
    73  	MOVQ	_rt0_amd64_lib_argv<>(SB), SI
    74  	JMP	runtime·rt0_go(SB)
    75  
    76  DATA _rt0_amd64_lib_argc<>(SB)/8, $0
    77  GLOBL _rt0_amd64_lib_argc<>(SB),NOPTR, $8
    78  DATA _rt0_amd64_lib_argv<>(SB)/8, $0
    79  GLOBL _rt0_amd64_lib_argv<>(SB),NOPTR, $8
    80  
    81  #ifdef GOAMD64_v2
    82  DATA bad_cpu_msg<>+0x00(SB)/84, $"This program can only be run on AMD64 processors with v2 microarchitecture support.\n"
    83  #endif
    84  
    85  #ifdef GOAMD64_v3
    86  DATA bad_cpu_msg<>+0x00(SB)/84, $"This program can only be run on AMD64 processors with v3 microarchitecture support.\n"
    87  #endif
    88  
    89  #ifdef GOAMD64_v4
    90  DATA bad_cpu_msg<>+0x00(SB)/84, $"This program can only be run on AMD64 processors with v4 microarchitecture support.\n"
    91  #endif
    92  
    93  GLOBL bad_cpu_msg<>(SB), RODATA, $84
    94  
    95  // Define a list of AMD64 microarchitecture level features
    96  // https://en.wikipedia.org/wiki/X86-64#Microarchitecture_levels
    97  
    98                       // SSE3     SSSE3    CMPXCHNG16 SSE4.1    SSE4.2    POPCNT
    99  #define V2_FEATURES_CX (1 << 0 | 1 << 9 | 1 << 13  | 1 << 19 | 1 << 20 | 1 << 23)
   100                           // LAHF/SAHF
   101  #define V2_EXT_FEATURES_CX (1 << 0)
   102                                        // FMA       MOVBE     OSXSAVE   AVX       F16C
   103  #define V3_FEATURES_CX (V2_FEATURES_CX | 1 << 12 | 1 << 22 | 1 << 27 | 1 << 28 | 1 << 29)
   104                                                // ABM (FOR LZNCT)
   105  #define V3_EXT_FEATURES_CX (V2_EXT_FEATURES_CX | 1 << 5)
   106                           // BMI1     AVX2     BMI2
   107  #define V3_EXT_FEATURES_BX (1 << 3 | 1 << 5 | 1 << 8)
   108                         // XMM      YMM
   109  #define V3_OS_SUPPORT_AX (1 << 1 | 1 << 2)
   110  
   111  #define V4_FEATURES_CX V3_FEATURES_CX
   112  
   113  #define V4_EXT_FEATURES_CX V3_EXT_FEATURES_CX
   114                                                // AVX512F   AVX512DQ  AVX512CD  AVX512BW  AVX512VL
   115  #define V4_EXT_FEATURES_BX (V3_EXT_FEATURES_BX | 1 << 16 | 1 << 17 | 1 << 28 | 1 << 30 | 1 << 31)
   116                                            // OPMASK   ZMM
   117  #define V4_OS_SUPPORT_AX (V3_OS_SUPPORT_AX | 1 << 5 | (1 << 6 | 1 << 7))
   118  
   119  #ifdef GOAMD64_v2
   120  #define NEED_MAX_CPUID 0x80000001
   121  #define NEED_FEATURES_CX V2_FEATURES_CX
   122  #define NEED_EXT_FEATURES_CX V2_EXT_FEATURES_CX
   123  #endif
   124  
   125  #ifdef GOAMD64_v3
   126  #define NEED_MAX_CPUID 0x80000001
   127  #define NEED_FEATURES_CX V3_FEATURES_CX
   128  #define NEED_EXT_FEATURES_CX V3_EXT_FEATURES_CX
   129  #define NEED_EXT_FEATURES_BX V3_EXT_FEATURES_BX
   130  #define NEED_OS_SUPPORT_AX V3_OS_SUPPORT_AX
   131  #endif
   132  
   133  #ifdef GOAMD64_v4
   134  #define NEED_MAX_CPUID 0x80000001
   135  #define NEED_FEATURES_CX V4_FEATURES_CX
   136  #define NEED_EXT_FEATURES_CX V4_EXT_FEATURES_CX
   137  #define NEED_EXT_FEATURES_BX V4_EXT_FEATURES_BX
   138  
   139  // Darwin requires a different approach to check AVX512 support, see CL 285572.
   140  #ifdef GOOS_darwin
   141  #define NEED_OS_SUPPORT_AX V3_OS_SUPPORT_AX
   142  // These values are from:
   143  // https://github.com/apple/darwin-xnu/blob/xnu-4570.1.46/osfmk/i386/cpu_capabilities.h
   144  #define commpage64_base_address         0x00007fffffe00000
   145  #define commpage64_cpu_capabilities64   (commpage64_base_address+0x010)
   146  #define commpage64_version              (commpage64_base_address+0x01E)
   147  #define hasAVX512F                      0x0000004000000000
   148  #define hasAVX512CD                     0x0000008000000000
   149  #define hasAVX512DQ                     0x0000010000000000
   150  #define hasAVX512BW                     0x0000020000000000
   151  #define hasAVX512VL                     0x0000100000000000
   152  #define NEED_DARWIN_SUPPORT             (hasAVX512F | hasAVX512DQ | hasAVX512CD | hasAVX512BW | hasAVX512VL)
   153  #else
   154  #define NEED_OS_SUPPORT_AX V4_OS_SUPPORT_AX
   155  #endif
   156  
   157  #endif
   158  
   159  TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
   160  	// copy arguments forward on an even stack
   161  	MOVQ	DI, AX		// argc
   162  	MOVQ	SI, BX		// argv
   163  	SUBQ	$(5*8), SP		// 3args 2auto
   164  	ANDQ	$~15, SP
   165  	MOVQ	AX, 24(SP)
   166  	MOVQ	BX, 32(SP)
   167  
   168  	// create istack out of the given (operating system) stack.
   169  	// _cgo_init may update stackguard.
   170  	MOVQ	$runtime·g0(SB), DI
   171  	LEAQ	(-64*1024)(SP), BX
   172  	MOVQ	BX, g_stackguard0(DI)
   173  	MOVQ	BX, g_stackguard1(DI)
   174  	MOVQ	BX, (g_stack+stack_lo)(DI)
   175  	MOVQ	SP, (g_stack+stack_hi)(DI)
   176  
   177  	// find out information about the processor we're on
   178  	MOVL	$0, AX
   179  	CPUID
   180  	CMPL	AX, $0
   181  	JE	nocpuinfo
   182  
   183  	CMPL	BX, $0x756E6547  // "Genu"
   184  	JNE	notintel
   185  	CMPL	DX, $0x49656E69  // "ineI"
   186  	JNE	notintel
   187  	CMPL	CX, $0x6C65746E  // "ntel"
   188  	JNE	notintel
   189  	MOVB	$1, runtime·isIntel(SB)
   190  
   191  notintel:
   192  	// Load EAX=1 cpuid flags
   193  	MOVL	$1, AX
   194  	CPUID
   195  	MOVL	AX, runtime·processorVersionInfo(SB)
   196  
   197  nocpuinfo:
   198  	// if there is an _cgo_init, call it.
   199  	MOVQ	_cgo_init(SB), AX
   200  	TESTQ	AX, AX
   201  	JZ	needtls
   202  	// arg 1: g0, already in DI
   203  	MOVQ	$setg_gcc<>(SB), SI // arg 2: setg_gcc
   204  	MOVQ	$0, DX	// arg 3, 4: not used when using platform's TLS
   205  	MOVQ	$0, CX
   206  #ifdef GOOS_android
   207  	MOVQ	$runtime·tls_g(SB), DX 	// arg 3: &tls_g
   208  	// arg 4: TLS base, stored in slot 0 (Android's TLS_SLOT_SELF).
   209  	// Compensate for tls_g (+16).
   210  	MOVQ	-16(TLS), CX
   211  #endif
   212  #ifdef GOOS_windows
   213  	MOVQ	$runtime·tls_g(SB), DX 	// arg 3: &tls_g
   214  	// Adjust for the Win64 calling convention.
   215  	MOVQ	CX, R9 // arg 4
   216  	MOVQ	DX, R8 // arg 3
   217  	MOVQ	SI, DX // arg 2
   218  	MOVQ	DI, CX // arg 1
   219  #endif
   220  	CALL	AX
   221  
   222  	// update stackguard after _cgo_init
   223  	MOVQ	$runtime·g0(SB), CX
   224  	MOVQ	(g_stack+stack_lo)(CX), AX
   225  	ADDQ	$const_stackGuard, AX
   226  	MOVQ	AX, g_stackguard0(CX)
   227  	MOVQ	AX, g_stackguard1(CX)
   228  
   229  #ifndef GOOS_windows
   230  	JMP ok
   231  #endif
   232  needtls:
   233  #ifdef GOOS_plan9
   234  	// skip TLS setup on Plan 9
   235  	JMP ok
   236  #endif
   237  #ifdef GOOS_solaris
   238  	// skip TLS setup on Solaris
   239  	JMP ok
   240  #endif
   241  #ifdef GOOS_illumos
   242  	// skip TLS setup on illumos
   243  	JMP ok
   244  #endif
   245  #ifdef GOOS_darwin
   246  	// skip TLS setup on Darwin
   247  	JMP ok
   248  #endif
   249  #ifdef GOOS_openbsd
   250  	// skip TLS setup on OpenBSD
   251  	JMP ok
   252  #endif
   253  
   254  #ifdef GOOS_windows
   255  	CALL	runtime·wintls(SB)
   256  #endif
   257  
   258  	LEAQ	runtime·m0+m_tls(SB), DI
   259  	CALL	runtime·settls(SB)
   260  
   261  	// store through it, to make sure it works
   262  	get_tls(BX)
   263  	MOVQ	$0x123, g(BX)
   264  	MOVQ	runtime·m0+m_tls(SB), AX
   265  	CMPQ	AX, $0x123
   266  	JEQ 2(PC)
   267  	CALL	runtime·abort(SB)
   268  ok:
   269  	// set the per-goroutine and per-mach "registers"
   270  	get_tls(BX)
   271  	LEAQ	runtime·g0(SB), CX
   272  	MOVQ	CX, g(BX)
   273  	LEAQ	runtime·m0(SB), AX
   274  
   275  	// save m->g0 = g0
   276  	MOVQ	CX, m_g0(AX)
   277  	// save m0 to g0->m
   278  	MOVQ	AX, g_m(CX)
   279  
   280  	CLD				// convention is D is always left cleared
   281  
   282  	// Check GOAMD64 requirements
   283  	// We need to do this after setting up TLS, so that
   284  	// we can report an error if there is a failure. See issue 49586.
   285  #ifdef NEED_FEATURES_CX
   286  	MOVL	$0, AX
   287  	CPUID
   288  	CMPL	AX, $0
   289  	JE	bad_cpu
   290  	MOVL	$1, AX
   291  	CPUID
   292  	ANDL	$NEED_FEATURES_CX, CX
   293  	CMPL	CX, $NEED_FEATURES_CX
   294  	JNE	bad_cpu
   295  #endif
   296  
   297  #ifdef NEED_MAX_CPUID
   298  	MOVL	$0x80000000, AX
   299  	CPUID
   300  	CMPL	AX, $NEED_MAX_CPUID
   301  	JL	bad_cpu
   302  #endif
   303  
   304  #ifdef NEED_EXT_FEATURES_BX
   305  	MOVL	$7, AX
   306  	MOVL	$0, CX
   307  	CPUID
   308  	ANDL	$NEED_EXT_FEATURES_BX, BX
   309  	CMPL	BX, $NEED_EXT_FEATURES_BX
   310  	JNE	bad_cpu
   311  #endif
   312  
   313  #ifdef NEED_EXT_FEATURES_CX
   314  	MOVL	$0x80000001, AX
   315  	CPUID
   316  	ANDL	$NEED_EXT_FEATURES_CX, CX
   317  	CMPL	CX, $NEED_EXT_FEATURES_CX
   318  	JNE	bad_cpu
   319  #endif
   320  
   321  #ifdef NEED_OS_SUPPORT_AX
   322  	XORL    CX, CX
   323  	XGETBV
   324  	ANDL	$NEED_OS_SUPPORT_AX, AX
   325  	CMPL	AX, $NEED_OS_SUPPORT_AX
   326  	JNE	bad_cpu
   327  #endif
   328  
   329  #ifdef NEED_DARWIN_SUPPORT
   330  	MOVQ	$commpage64_version, BX
   331  	CMPW	(BX), $13  // cpu_capabilities64 undefined in versions < 13
   332  	JL	bad_cpu
   333  	MOVQ	$commpage64_cpu_capabilities64, BX
   334  	MOVQ	(BX), BX
   335  	MOVQ	$NEED_DARWIN_SUPPORT, CX
   336  	ANDQ	CX, BX
   337  	CMPQ	BX, CX
   338  	JNE	bad_cpu
   339  #endif
   340  
   341  	CALL	runtime·check(SB)
   342  
   343  	MOVL	24(SP), AX		// copy argc
   344  	MOVL	AX, 0(SP)
   345  	MOVQ	32(SP), AX		// copy argv
   346  	MOVQ	AX, 8(SP)
   347  	CALL	runtime·args(SB)
   348  	CALL	runtime·osinit(SB)
   349  	CALL	runtime·schedinit(SB)
   350  
   351  	// create a new goroutine to start program
   352  	MOVQ	$runtime·mainPC(SB), AX		// entry
   353  	PUSHQ	AX
   354  	CALL	runtime·newproc(SB)
   355  	POPQ	AX
   356  
   357  	// start this M
   358  	CALL	runtime·mstart(SB)
   359  
   360  	CALL	runtime·abort(SB)	// mstart should never return
   361  	RET
   362  
   363  bad_cpu: // show that the program requires a certain microarchitecture level.
   364  	MOVQ	$2, 0(SP)
   365  	MOVQ	$bad_cpu_msg<>(SB), AX
   366  	MOVQ	AX, 8(SP)
   367  	MOVQ	$84, 16(SP)
   368  	CALL	runtime·write(SB)
   369  	MOVQ	$1, 0(SP)
   370  	CALL	runtime·exit(SB)
   371  	CALL	runtime·abort(SB)
   372  	RET
   373  
   374  	// Prevent dead-code elimination of debugCallV2, which is
   375  	// intended to be called by debuggers.
   376  	MOVQ	$runtime·debugCallV2<ABIInternal>(SB), AX
   377  	RET
   378  
   379  // mainPC is a function value for runtime.main, to be passed to newproc.
   380  // The reference to runtime.main is made via ABIInternal, since the
   381  // actual function (not the ABI0 wrapper) is needed by newproc.
   382  DATA	runtime·mainPC+0(SB)/8,$runtime·main<ABIInternal>(SB)
   383  GLOBL	runtime·mainPC(SB),RODATA,$8
   384  
   385  TEXT runtime·breakpoint(SB),NOSPLIT,$0-0
   386  	BYTE	$0xcc
   387  	RET
   388  
   389  TEXT runtime·asminit(SB),NOSPLIT,$0-0
   390  	// No per-thread init.
   391  	RET
   392  
   393  TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME|NOFRAME,$0
   394  	CALL	runtime·mstart0(SB)
   395  	RET // not reached
   396  
   397  /*
   398   *  go-routine
   399   */
   400  
   401  // func gogo(buf *gobuf)
   402  // restore state from Gobuf; longjmp
   403  TEXT runtime·gogo(SB), NOSPLIT, $0-8
   404  	MOVQ	buf+0(FP), BX		// gobuf
   405  	MOVQ	gobuf_g(BX), DX
   406  	MOVQ	0(DX), CX		// make sure g != nil
   407  	JMP	gogo<>(SB)
   408  
   409  TEXT gogo<>(SB), NOSPLIT, $0
   410  	get_tls(CX)
   411  	MOVQ	DX, g(CX)
   412  	MOVQ	DX, R14		// set the g register
   413  	MOVQ	gobuf_sp(BX), SP	// restore SP
   414  	MOVQ	gobuf_ret(BX), AX
   415  	MOVQ	gobuf_ctxt(BX), DX
   416  	MOVQ	gobuf_bp(BX), BP
   417  	MOVQ	$0, gobuf_sp(BX)	// clear to help garbage collector
   418  	MOVQ	$0, gobuf_ret(BX)
   419  	MOVQ	$0, gobuf_ctxt(BX)
   420  	MOVQ	$0, gobuf_bp(BX)
   421  	MOVQ	gobuf_pc(BX), BX
   422  	JMP	BX
   423  
   424  // func mcall(fn func(*g))
   425  // Switch to m->g0's stack, call fn(g).
   426  // Fn must never return. It should gogo(&g->sched)
   427  // to keep running g.
   428  TEXT runtime·mcall<ABIInternal>(SB), NOSPLIT, $0-8
   429  	MOVQ	AX, DX	// DX = fn
   430  
   431  	// Save state in g->sched. The caller's SP and PC are restored by gogo to
   432  	// resume execution in the caller's frame (implicit return). The caller's BP
   433  	// is also restored to support frame pointer unwinding.
   434  	MOVQ	SP, BX	// hide (SP) reads from vet
   435  	MOVQ	8(BX), BX	// caller's PC
   436  	MOVQ	BX, (g_sched+gobuf_pc)(R14)
   437  	LEAQ	fn+0(FP), BX	// caller's SP
   438  	MOVQ	BX, (g_sched+gobuf_sp)(R14)
   439  	// Get the caller's frame pointer by dereferencing BP. Storing BP as it is
   440  	// can cause a frame pointer cycle, see CL 476235.
   441  	MOVQ	(BP), BX // caller's BP
   442  	MOVQ	BX, (g_sched+gobuf_bp)(R14)
   443  
   444  	// switch to m->g0 & its stack, call fn
   445  	MOVQ	g_m(R14), BX
   446  	MOVQ	m_g0(BX), SI	// SI = g.m.g0
   447  	CMPQ	SI, R14	// if g == m->g0 call badmcall
   448  	JNE	goodm
   449  	JMP	runtime·badmcall(SB)
   450  goodm:
   451  	MOVQ	R14, AX		// AX (and arg 0) = g
   452  	MOVQ	SI, R14		// g = g.m.g0
   453  	get_tls(CX)		// Set G in TLS
   454  	MOVQ	R14, g(CX)
   455  	MOVQ	(g_sched+gobuf_sp)(R14), SP	// sp = g0.sched.sp
   456  	PUSHQ	AX	// open up space for fn's arg spill slot
   457  	MOVQ	0(DX), R12
   458  	CALL	R12		// fn(g)
   459  	POPQ	AX
   460  	JMP	runtime·badmcall2(SB)
   461  	RET
   462  
   463  // systemstack_switch is a dummy routine that systemstack leaves at the bottom
   464  // of the G stack. We need to distinguish the routine that
   465  // lives at the bottom of the G stack from the one that lives
   466  // at the top of the system stack because the one at the top of
   467  // the system stack terminates the stack walk (see topofstack()).
   468  // The frame layout needs to match systemstack
   469  // so that it can pretend to be systemstack_switch.
   470  TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0
   471  	UNDEF
   472  	// Make sure this function is not leaf,
   473  	// so the frame is saved.
   474  	CALL	runtime·abort(SB)
   475  	RET
   476  
   477  // func systemstack(fn func())
   478  TEXT runtime·systemstack(SB), NOSPLIT, $0-8
   479  	MOVQ	fn+0(FP), DI	// DI = fn
   480  	get_tls(CX)
   481  	MOVQ	g(CX), AX	// AX = g
   482  	MOVQ	g_m(AX), BX	// BX = m
   483  
   484  	CMPQ	AX, m_gsignal(BX)
   485  	JEQ	noswitch
   486  
   487  	MOVQ	m_g0(BX), DX	// DX = g0
   488  	CMPQ	AX, DX
   489  	JEQ	noswitch
   490  
   491  	CMPQ	AX, m_curg(BX)
   492  	JNE	bad
   493  
   494  	// Switch stacks.
   495  	// The original frame pointer is stored in BP,
   496  	// which is useful for stack unwinding.
   497  	// Save our state in g->sched. Pretend to
   498  	// be systemstack_switch if the G stack is scanned.
   499  	CALL	gosave_systemstack_switch<>(SB)
   500  
   501  	// switch to g0
   502  	MOVQ	DX, g(CX)
   503  	MOVQ	DX, R14 // set the g register
   504  	MOVQ	(g_sched+gobuf_sp)(DX), SP
   505  
   506  	// call target function
   507  	MOVQ	DI, DX
   508  	MOVQ	0(DI), DI
   509  	CALL	DI
   510  
   511  	// switch back to g
   512  	get_tls(CX)
   513  	MOVQ	g(CX), AX
   514  	MOVQ	g_m(AX), BX
   515  	MOVQ	m_curg(BX), AX
   516  	MOVQ	AX, g(CX)
   517  	MOVQ	(g_sched+gobuf_sp)(AX), SP
   518  	MOVQ	(g_sched+gobuf_bp)(AX), BP
   519  	MOVQ	$0, (g_sched+gobuf_sp)(AX)
   520  	MOVQ	$0, (g_sched+gobuf_bp)(AX)
   521  	RET
   522  
   523  noswitch:
   524  	// already on m stack; tail call the function
   525  	// Using a tail call here cleans up tracebacks since we won't stop
   526  	// at an intermediate systemstack.
   527  	MOVQ	DI, DX
   528  	MOVQ	0(DI), DI
   529  	// The function epilogue is not called on a tail call.
   530  	// Pop BP from the stack to simulate it.
   531  	POPQ	BP
   532  	JMP	DI
   533  
   534  bad:
   535  	// Bad: g is not gsignal, not g0, not curg. What is it?
   536  	MOVQ	$runtime·badsystemstack(SB), AX
   537  	CALL	AX
   538  	INT	$3
   539  
   540  
   541  /*
   542   * support for morestack
   543   */
   544  
   545  // Called during function prolog when more stack is needed.
   546  //
   547  // The traceback routines see morestack on a g0 as being
   548  // the top of a stack (for example, morestack calling newstack
   549  // calling the scheduler calling newm calling gc), so we must
   550  // record an argument size. For that purpose, it has no arguments.
   551  TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
   552  	// Cannot grow scheduler stack (m->g0).
   553  	get_tls(CX)
   554  	MOVQ	g(CX), BX
   555  	MOVQ	g_m(BX), BX
   556  	MOVQ	m_g0(BX), SI
   557  	CMPQ	g(CX), SI
   558  	JNE	3(PC)
   559  	CALL	runtime·badmorestackg0(SB)
   560  	CALL	runtime·abort(SB)
   561  
   562  	// Cannot grow signal stack (m->gsignal).
   563  	MOVQ	m_gsignal(BX), SI
   564  	CMPQ	g(CX), SI
   565  	JNE	3(PC)
   566  	CALL	runtime·badmorestackgsignal(SB)
   567  	CALL	runtime·abort(SB)
   568  
   569  	// Called from f.
   570  	// Set m->morebuf to f's caller.
   571  	NOP	SP	// tell vet SP changed - stop checking offsets
   572  	MOVQ	8(SP), AX	// f's caller's PC
   573  	MOVQ	AX, (m_morebuf+gobuf_pc)(BX)
   574  	LEAQ	16(SP), AX	// f's caller's SP
   575  	MOVQ	AX, (m_morebuf+gobuf_sp)(BX)
   576  	get_tls(CX)
   577  	MOVQ	g(CX), SI
   578  	MOVQ	SI, (m_morebuf+gobuf_g)(BX)
   579  
   580  	// Set g->sched to context in f.
   581  	MOVQ	0(SP), AX // f's PC
   582  	MOVQ	AX, (g_sched+gobuf_pc)(SI)
   583  	LEAQ	8(SP), AX // f's SP
   584  	MOVQ	AX, (g_sched+gobuf_sp)(SI)
   585  	MOVQ	BP, (g_sched+gobuf_bp)(SI)
   586  	MOVQ	DX, (g_sched+gobuf_ctxt)(SI)
   587  
   588  	// Call newstack on m->g0's stack.
   589  	MOVQ	m_g0(BX), BX
   590  	MOVQ	BX, g(CX)
   591  	MOVQ	(g_sched+gobuf_sp)(BX), SP
   592  	MOVQ	(g_sched+gobuf_bp)(BX), BP
   593  	CALL	runtime·newstack(SB)
   594  	CALL	runtime·abort(SB)	// crash if newstack returns
   595  	RET
   596  
   597  // morestack but not preserving ctxt.
   598  TEXT runtime·morestack_noctxt(SB),NOSPLIT,$0
   599  	MOVL	$0, DX
   600  	JMP	runtime·morestack(SB)
   601  
   602  // spillArgs stores return values from registers to a *internal/abi.RegArgs in R12.
   603  TEXT ·spillArgs(SB),NOSPLIT,$0-0
   604  	MOVQ AX, 0(R12)
   605  	MOVQ BX, 8(R12)
   606  	MOVQ CX, 16(R12)
   607  	MOVQ DI, 24(R12)
   608  	MOVQ SI, 32(R12)
   609  	MOVQ R8, 40(R12)
   610  	MOVQ R9, 48(R12)
   611  	MOVQ R10, 56(R12)
   612  	MOVQ R11, 64(R12)
   613  	MOVQ X0, 72(R12)
   614  	MOVQ X1, 80(R12)
   615  	MOVQ X2, 88(R12)
   616  	MOVQ X3, 96(R12)
   617  	MOVQ X4, 104(R12)
   618  	MOVQ X5, 112(R12)
   619  	MOVQ X6, 120(R12)
   620  	MOVQ X7, 128(R12)
   621  	MOVQ X8, 136(R12)
   622  	MOVQ X9, 144(R12)
   623  	MOVQ X10, 152(R12)
   624  	MOVQ X11, 160(R12)
   625  	MOVQ X12, 168(R12)
   626  	MOVQ X13, 176(R12)
   627  	MOVQ X14, 184(R12)
   628  	RET
   629  
   630  // unspillArgs loads args into registers from a *internal/abi.RegArgs in R12.
   631  TEXT ·unspillArgs(SB),NOSPLIT,$0-0
   632  	MOVQ 0(R12), AX
   633  	MOVQ 8(R12), BX
   634  	MOVQ 16(R12), CX
   635  	MOVQ 24(R12), DI
   636  	MOVQ 32(R12), SI
   637  	MOVQ 40(R12), R8
   638  	MOVQ 48(R12), R9
   639  	MOVQ 56(R12), R10
   640  	MOVQ 64(R12), R11
   641  	MOVQ 72(R12), X0
   642  	MOVQ 80(R12), X1
   643  	MOVQ 88(R12), X2
   644  	MOVQ 96(R12), X3
   645  	MOVQ 104(R12), X4
   646  	MOVQ 112(R12), X5
   647  	MOVQ 120(R12), X6
   648  	MOVQ 128(R12), X7
   649  	MOVQ 136(R12), X8
   650  	MOVQ 144(R12), X9
   651  	MOVQ 152(R12), X10
   652  	MOVQ 160(R12), X11
   653  	MOVQ 168(R12), X12
   654  	MOVQ 176(R12), X13
   655  	MOVQ 184(R12), X14
   656  	RET
   657  
   658  // reflectcall: call a function with the given argument list
   659  // func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
   660  // we don't have variable-sized frames, so we use a small number
   661  // of constant-sized-frame functions to encode a few bits of size in the pc.
   662  // Caution: ugly multiline assembly macros in your future!
   663  
   664  #define DISPATCH(NAME,MAXSIZE)		\
   665  	CMPQ	CX, $MAXSIZE;		\
   666  	JA	3(PC);			\
   667  	MOVQ	$NAME(SB), AX;		\
   668  	JMP	AX
   669  // Note: can't just "JMP NAME(SB)" - bad inlining results.
   670  
   671  TEXT ·reflectcall(SB), NOSPLIT, $0-48
   672  	MOVLQZX frameSize+32(FP), CX
   673  	DISPATCH(runtime·call16, 16)
   674  	DISPATCH(runtime·call32, 32)
   675  	DISPATCH(runtime·call64, 64)
   676  	DISPATCH(runtime·call128, 128)
   677  	DISPATCH(runtime·call256, 256)
   678  	DISPATCH(runtime·call512, 512)
   679  	DISPATCH(runtime·call1024, 1024)
   680  	DISPATCH(runtime·call2048, 2048)
   681  	DISPATCH(runtime·call4096, 4096)
   682  	DISPATCH(runtime·call8192, 8192)
   683  	DISPATCH(runtime·call16384, 16384)
   684  	DISPATCH(runtime·call32768, 32768)
   685  	DISPATCH(runtime·call65536, 65536)
   686  	DISPATCH(runtime·call131072, 131072)
   687  	DISPATCH(runtime·call262144, 262144)
   688  	DISPATCH(runtime·call524288, 524288)
   689  	DISPATCH(runtime·call1048576, 1048576)
   690  	DISPATCH(runtime·call2097152, 2097152)
   691  	DISPATCH(runtime·call4194304, 4194304)
   692  	DISPATCH(runtime·call8388608, 8388608)
   693  	DISPATCH(runtime·call16777216, 16777216)
   694  	DISPATCH(runtime·call33554432, 33554432)
   695  	DISPATCH(runtime·call67108864, 67108864)
   696  	DISPATCH(runtime·call134217728, 134217728)
   697  	DISPATCH(runtime·call268435456, 268435456)
   698  	DISPATCH(runtime·call536870912, 536870912)
   699  	DISPATCH(runtime·call1073741824, 1073741824)
   700  	MOVQ	$runtime·badreflectcall(SB), AX
   701  	JMP	AX
   702  
   703  #define CALLFN(NAME,MAXSIZE)			\
   704  TEXT NAME(SB), WRAPPER, $MAXSIZE-48;		\
   705  	NO_LOCAL_POINTERS;			\
   706  	/* copy arguments to stack */		\
   707  	MOVQ	stackArgs+16(FP), SI;		\
   708  	MOVLQZX stackArgsSize+24(FP), CX;		\
   709  	MOVQ	SP, DI;				\
   710  	REP;MOVSB;				\
   711  	/* set up argument registers */		\
   712  	MOVQ    regArgs+40(FP), R12;		\
   713  	CALL    ·unspillArgs(SB);		\
   714  	/* call function */			\
   715  	MOVQ	f+8(FP), DX;			\
   716  	PCDATA  $PCDATA_StackMapIndex, $0;	\
   717  	MOVQ	(DX), R12;			\
   718  	CALL	R12;				\
   719  	/* copy register return values back */		\
   720  	MOVQ    regArgs+40(FP), R12;		\
   721  	CALL    ·spillArgs(SB);		\
   722  	MOVLQZX	stackArgsSize+24(FP), CX;		\
   723  	MOVLQZX	stackRetOffset+28(FP), BX;		\
   724  	MOVQ	stackArgs+16(FP), DI;		\
   725  	MOVQ	stackArgsType+0(FP), DX;		\
   726  	MOVQ	SP, SI;				\
   727  	ADDQ	BX, DI;				\
   728  	ADDQ	BX, SI;				\
   729  	SUBQ	BX, CX;				\
   730  	CALL	callRet<>(SB);			\
   731  	RET
   732  
   733  // callRet copies return values back at the end of call*. This is a
   734  // separate function so it can allocate stack space for the arguments
   735  // to reflectcallmove. It does not follow the Go ABI; it expects its
   736  // arguments in registers.
   737  TEXT callRet<>(SB), NOSPLIT, $40-0
   738  	NO_LOCAL_POINTERS
   739  	MOVQ	DX, 0(SP)
   740  	MOVQ	DI, 8(SP)
   741  	MOVQ	SI, 16(SP)
   742  	MOVQ	CX, 24(SP)
   743  	MOVQ	R12, 32(SP)
   744  	CALL	runtime·reflectcallmove(SB)
   745  	RET
   746  
   747  CALLFN(·call16, 16)
   748  CALLFN(·call32, 32)
   749  CALLFN(·call64, 64)
   750  CALLFN(·call128, 128)
   751  CALLFN(·call256, 256)
   752  CALLFN(·call512, 512)
   753  CALLFN(·call1024, 1024)
   754  CALLFN(·call2048, 2048)
   755  CALLFN(·call4096, 4096)
   756  CALLFN(·call8192, 8192)
   757  CALLFN(·call16384, 16384)
   758  CALLFN(·call32768, 32768)
   759  CALLFN(·call65536, 65536)
   760  CALLFN(·call131072, 131072)
   761  CALLFN(·call262144, 262144)
   762  CALLFN(·call524288, 524288)
   763  CALLFN(·call1048576, 1048576)
   764  CALLFN(·call2097152, 2097152)
   765  CALLFN(·call4194304, 4194304)
   766  CALLFN(·call8388608, 8388608)
   767  CALLFN(·call16777216, 16777216)
   768  CALLFN(·call33554432, 33554432)
   769  CALLFN(·call67108864, 67108864)
   770  CALLFN(·call134217728, 134217728)
   771  CALLFN(·call268435456, 268435456)
   772  CALLFN(·call536870912, 536870912)
   773  CALLFN(·call1073741824, 1073741824)
   774  
   775  TEXT runtime·procyield(SB),NOSPLIT,$0-0
   776  	MOVL	cycles+0(FP), AX
   777  again:
   778  	PAUSE
   779  	SUBL	$1, AX
   780  	JNZ	again
   781  	RET
   782  
   783  
   784  TEXT ·publicationBarrier<ABIInternal>(SB),NOSPLIT,$0-0
   785  	// Stores are already ordered on x86, so this is just a
   786  	// compile barrier.
   787  	RET
   788  
   789  // Save state of caller into g->sched,
   790  // but using fake PC from systemstack_switch.
   791  // Must only be called from functions with frame pointer
   792  // and without locals ($0) or else unwinding from
   793  // systemstack_switch is incorrect.
   794  // Smashes R9.
   795  TEXT gosave_systemstack_switch<>(SB),NOSPLIT|NOFRAME,$0
   796  	// Take systemstack_switch PC and add 8 bytes to skip
   797  	// the prologue. The final location does not matter
   798  	// as long as we are between the prologue and the epilogue.
   799  	MOVQ	$runtime·systemstack_switch+8(SB), R9
   800  	MOVQ	R9, (g_sched+gobuf_pc)(R14)
   801  	LEAQ	8(SP), R9
   802  	MOVQ	R9, (g_sched+gobuf_sp)(R14)
   803  	MOVQ	$0, (g_sched+gobuf_ret)(R14)
   804  	MOVQ	BP, (g_sched+gobuf_bp)(R14)
   805  	// Assert ctxt is zero. See func save.
   806  	MOVQ	(g_sched+gobuf_ctxt)(R14), R9
   807  	TESTQ	R9, R9
   808  	JZ	2(PC)
   809  	CALL	runtime·abort(SB)
   810  	RET
   811  
   812  // func asmcgocall_no_g(fn, arg unsafe.Pointer)
   813  // Call fn(arg) aligned appropriately for the gcc ABI.
   814  // Called on a system stack, and there may be no g yet (during needm).
   815  TEXT ·asmcgocall_no_g(SB),NOSPLIT,$32-16
   816  	MOVQ	fn+0(FP), AX
   817  	MOVQ	arg+8(FP), BX
   818  	MOVQ	SP, DX
   819  	ANDQ	$~15, SP	// alignment
   820  	MOVQ	DX, 8(SP)
   821  	MOVQ	BX, DI		// DI = first argument in AMD64 ABI
   822  	MOVQ	BX, CX		// CX = first argument in Win64
   823  	CALL	AX
   824  	MOVQ	8(SP), DX
   825  	MOVQ	DX, SP
   826  	RET
   827  
   828  // func asmcgocall(fn, arg unsafe.Pointer) int32
   829  // Call fn(arg) on the scheduler stack,
   830  // aligned appropriately for the gcc ABI.
   831  // See cgocall.go for more details.
   832  TEXT ·asmcgocall(SB),NOSPLIT,$0-20
   833  	MOVQ	fn+0(FP), AX
   834  	MOVQ	arg+8(FP), BX
   835  
   836  	MOVQ	SP, DX
   837  
   838  	// Figure out if we need to switch to m->g0 stack.
   839  	// We get called to create new OS threads too, and those
   840  	// come in on the m->g0 stack already. Or we might already
   841  	// be on the m->gsignal stack.
   842  	get_tls(CX)
   843  	MOVQ	g(CX), DI
   844  	CMPQ	DI, $0
   845  	JEQ	nosave
   846  	MOVQ	g_m(DI), R8
   847  	MOVQ	m_gsignal(R8), SI
   848  	CMPQ	DI, SI
   849  	JEQ	nosave
   850  	MOVQ	m_g0(R8), SI
   851  	CMPQ	DI, SI
   852  	JEQ	nosave
   853  
   854  	// Switch to system stack.
   855  	// The original frame pointer is stored in BP,
   856  	// which is useful for stack unwinding.
   857  	CALL	gosave_systemstack_switch<>(SB)
   858  	MOVQ	SI, g(CX)
   859  	MOVQ	(g_sched+gobuf_sp)(SI), SP
   860  
   861  	// Now on a scheduling stack (a pthread-created stack).
   862  	// Make sure we have enough room for 4 stack-backed fast-call
   863  	// registers as per windows amd64 calling convention.
   864  	SUBQ	$64, SP
   865  	ANDQ	$~15, SP	// alignment for gcc ABI
   866  	MOVQ	DI, 48(SP)	// save g
   867  	MOVQ	(g_stack+stack_hi)(DI), DI
   868  	SUBQ	DX, DI
   869  	MOVQ	DI, 40(SP)	// save depth in stack (can't just save SP, as stack might be copied during a callback)
   870  	MOVQ	BX, DI		// DI = first argument in AMD64 ABI
   871  	MOVQ	BX, CX		// CX = first argument in Win64
   872  	CALL	AX
   873  
   874  	// Restore registers, g, stack pointer.
   875  	get_tls(CX)
   876  	MOVQ	48(SP), DI
   877  	MOVQ	(g_stack+stack_hi)(DI), SI
   878  	SUBQ	40(SP), SI
   879  	MOVQ	DI, g(CX)
   880  	MOVQ	SI, SP
   881  
   882  	MOVL	AX, ret+16(FP)
   883  	RET
   884  
   885  nosave:
   886  	// Running on a system stack, perhaps even without a g.
   887  	// Having no g can happen during thread creation or thread teardown
   888  	// (see needm/dropm on Solaris, for example).
   889  	// This code is like the above sequence but without saving/restoring g
   890  	// and without worrying about the stack moving out from under us
   891  	// (because we're on a system stack, not a goroutine stack).
   892  	// The above code could be used directly if already on a system stack,
   893  	// but then the only path through this code would be a rare case on Solaris.
   894  	// Using this code for all "already on system stack" calls exercises it more,
   895  	// which should help keep it correct.
   896  	SUBQ	$64, SP
   897  	ANDQ	$~15, SP
   898  	MOVQ	$0, 48(SP)		// where above code stores g, in case someone looks during debugging
   899  	MOVQ	DX, 40(SP)	// save original stack pointer
   900  	MOVQ	BX, DI		// DI = first argument in AMD64 ABI
   901  	MOVQ	BX, CX		// CX = first argument in Win64
   902  	CALL	AX
   903  	MOVQ	40(SP), SI	// restore original stack pointer
   904  	MOVQ	SI, SP
   905  	MOVL	AX, ret+16(FP)
   906  	RET
   907  
   908  #ifdef GOOS_windows
   909  // Dummy TLS that's used on Windows so that we don't crash trying
   910  // to restore the G register in needm. needm and its callees are
   911  // very careful never to actually use the G, the TLS just can't be
   912  // unset since we're in Go code.
   913  GLOBL zeroTLS<>(SB),RODATA,$const_tlsSize
   914  #endif
   915  
   916  // func cgocallback(fn, frame unsafe.Pointer, ctxt uintptr)
   917  // See cgocall.go for more details.
   918  TEXT ·cgocallback(SB),NOSPLIT,$24-24
   919  	NO_LOCAL_POINTERS
   920  
   921  	// If g is nil, Go did not create the current thread.
   922  	// Call needm to obtain one m for temporary use.
   923  	// In this case, we're running on the thread stack, so there's
   924  	// lots of space, but the linker doesn't know. Hide the call from
   925  	// the linker analysis by using an indirect call through AX.
   926  	get_tls(CX)
   927  #ifdef GOOS_windows
   928  	MOVL	$0, BX
   929  	CMPQ	CX, $0
   930  	JEQ	2(PC)
   931  #endif
   932  	MOVQ	g(CX), BX
   933  	CMPQ	BX, $0
   934  	JEQ	needm
   935  	MOVQ	g_m(BX), BX
   936  	MOVQ	BX, savedm-8(SP)	// saved copy of oldm
   937  	JMP	havem
   938  needm:
   939  #ifdef GOOS_windows
   940  	// Set up a dummy TLS value. needm is careful not to use it,
   941  	// but it needs to be there to prevent autogenerated code from
   942  	// crashing when it loads from it.
   943  	// We don't need to clear it or anything later because needm
   944  	// will set up TLS properly.
   945  	MOVQ	$zeroTLS<>(SB), DI
   946  	CALL	runtime·settls(SB)
   947  #endif
   948  	// On some platforms (Windows) we cannot call needm through
   949  	// an ABI wrapper because there's no TLS set up, and the ABI
   950  	// wrapper will try to restore the G register (R14) from TLS.
   951  	// Clear X15 because Go expects it and we're not calling
   952  	// through a wrapper, but otherwise avoid setting the G
   953  	// register in the wrapper and call needm directly. It
   954  	// takes no arguments and doesn't return any values so
   955  	// there's no need to handle that. Clear R14 so that there's
   956  	// a bad value in there, in case needm tries to use it.
   957  	XORPS	X15, X15
   958  	XORQ    R14, R14
   959  	MOVQ	$runtime·needm<ABIInternal>(SB), AX
   960  	CALL	AX
   961  	MOVQ	$0, savedm-8(SP) // dropm on return
   962  	get_tls(CX)
   963  	MOVQ	g(CX), BX
   964  	MOVQ	g_m(BX), BX
   965  
   966  	// Set m->sched.sp = SP, so that if a panic happens
   967  	// during the function we are about to execute, it will
   968  	// have a valid SP to run on the g0 stack.
   969  	// The next few lines (after the havem label)
   970  	// will save this SP onto the stack and then write
   971  	// the same SP back to m->sched.sp. That seems redundant,
   972  	// but if an unrecovered panic happens, unwindm will
   973  	// restore the g->sched.sp from the stack location
   974  	// and then systemstack will try to use it. If we don't set it here,
   975  	// that restored SP will be uninitialized (typically 0) and
   976  	// will not be usable.
   977  	MOVQ	m_g0(BX), SI
   978  	MOVQ	SP, (g_sched+gobuf_sp)(SI)
   979  
   980  havem:
   981  	// Now there's a valid m, and we're running on its m->g0.
   982  	// Save current m->g0->sched.sp on stack and then set it to SP.
   983  	// Save current sp in m->g0->sched.sp in preparation for
   984  	// switch back to m->curg stack.
   985  	// NOTE: unwindm knows that the saved g->sched.sp is at 0(SP).
   986  	MOVQ	m_g0(BX), SI
   987  	MOVQ	(g_sched+gobuf_sp)(SI), AX
   988  	MOVQ	AX, 0(SP)
   989  	MOVQ	SP, (g_sched+gobuf_sp)(SI)
   990  
   991  	// Switch to m->curg stack and call runtime.cgocallbackg.
   992  	// Because we are taking over the execution of m->curg
   993  	// but *not* resuming what had been running, we need to
   994  	// save that information (m->curg->sched) so we can restore it.
   995  	// We can restore m->curg->sched.sp easily, because calling
   996  	// runtime.cgocallbackg leaves SP unchanged upon return.
   997  	// To save m->curg->sched.pc, we push it onto the curg stack and
   998  	// open a frame the same size as cgocallback's g0 frame.
   999  	// Once we switch to the curg stack, the pushed PC will appear
  1000  	// to be the return PC of cgocallback, so that the traceback
  1001  	// will seamlessly trace back into the earlier calls.
  1002  	MOVQ	m_curg(BX), SI
  1003  	MOVQ	SI, g(CX)
  1004  	MOVQ	(g_sched+gobuf_sp)(SI), DI  // prepare stack as DI
  1005  	MOVQ	(g_sched+gobuf_pc)(SI), BX
  1006  	MOVQ	BX, -8(DI)  // "push" return PC on the g stack
  1007  	// Gather our arguments into registers.
  1008  	MOVQ	fn+0(FP), BX
  1009  	MOVQ	frame+8(FP), CX
  1010  	MOVQ	ctxt+16(FP), DX
  1011  	// Compute the size of the frame, including return PC and, if
  1012  	// GOEXPERIMENT=framepointer, the saved base pointer
  1013  	LEAQ	fn+0(FP), AX
  1014  	SUBQ	SP, AX   // AX is our actual frame size
  1015  	SUBQ	AX, DI   // Allocate the same frame size on the g stack
  1016  	MOVQ	DI, SP
  1017  
  1018  	MOVQ	BX, 0(SP)
  1019  	MOVQ	CX, 8(SP)
  1020  	MOVQ	DX, 16(SP)
  1021  	MOVQ	$runtime·cgocallbackg(SB), AX
  1022  	CALL	AX	// indirect call to bypass nosplit check. We're on a different stack now.
  1023  
  1024  	// Compute the size of the frame again. FP and SP have
  1025  	// completely different values here than they did above,
  1026  	// but only their difference matters.
  1027  	LEAQ	fn+0(FP), AX
  1028  	SUBQ	SP, AX
  1029  
  1030  	// Restore g->sched (== m->curg->sched) from saved values.
  1031  	get_tls(CX)
  1032  	MOVQ	g(CX), SI
  1033  	MOVQ	SP, DI
  1034  	ADDQ	AX, DI
  1035  	MOVQ	-8(DI), BX
  1036  	MOVQ	BX, (g_sched+gobuf_pc)(SI)
  1037  	MOVQ	DI, (g_sched+gobuf_sp)(SI)
  1038  
  1039  	// Switch back to m->g0's stack and restore m->g0->sched.sp.
  1040  	// (Unlike m->curg, the g0 goroutine never uses sched.pc,
  1041  	// so we do not have to restore it.)
  1042  	MOVQ	g(CX), BX
  1043  	MOVQ	g_m(BX), BX
  1044  	MOVQ	m_g0(BX), SI
  1045  	MOVQ	SI, g(CX)
  1046  	MOVQ	(g_sched+gobuf_sp)(SI), SP
  1047  	MOVQ	0(SP), AX
  1048  	MOVQ	AX, (g_sched+gobuf_sp)(SI)
  1049  
  1050  	// If the m on entry was nil, we called needm above to borrow an m
  1051  	// for the duration of the call. Since the call is over, return it with dropm.
  1052  	MOVQ	savedm-8(SP), BX
  1053  	CMPQ	BX, $0
  1054  	JNE	done
  1055  	MOVQ	$runtime·dropm(SB), AX
  1056  	CALL	AX
  1057  #ifdef GOOS_windows
  1058  	// We need to clear the TLS pointer in case the next
  1059  	// thread that comes into Go tries to reuse that space
  1060  	// but uses the same M.
  1061  	XORQ	DI, DI
  1062  	CALL	runtime·settls(SB)
  1063  #endif
  1064  done:
  1065  
  1066  	// Done!
  1067  	RET
  1068  
  1069  // func setg(gg *g)
  1070  // set g. for use by needm.
  1071  TEXT runtime·setg(SB), NOSPLIT, $0-8
  1072  	MOVQ	gg+0(FP), BX
  1073  	get_tls(CX)
  1074  	MOVQ	BX, g(CX)
  1075  	RET
  1076  
  1077  // void setg_gcc(G*); set g called from gcc.
  1078  TEXT setg_gcc<>(SB),NOSPLIT,$0
  1079  	get_tls(AX)
  1080  	MOVQ	DI, g(AX)
  1081  	MOVQ	DI, R14 // set the g register
  1082  	RET
  1083  
  1084  TEXT runtime·abort(SB),NOSPLIT,$0-0
  1085  	INT	$3
  1086  loop:
  1087  	JMP	loop
  1088  
  1089  // check that SP is in range [g->stack.lo, g->stack.hi)
  1090  TEXT runtime·stackcheck(SB), NOSPLIT|NOFRAME, $0-0
  1091  	get_tls(CX)
  1092  	MOVQ	g(CX), AX
  1093  	CMPQ	(g_stack+stack_hi)(AX), SP
  1094  	JHI	2(PC)
  1095  	CALL	runtime·abort(SB)
  1096  	CMPQ	SP, (g_stack+stack_lo)(AX)
  1097  	JHI	2(PC)
  1098  	CALL	runtime·abort(SB)
  1099  	RET
  1100  
  1101  // func cputicks() int64
  1102  TEXT runtime·cputicks(SB),NOSPLIT,$0-0
  1103  	CMPB	internal∕cpu·X86+const_offsetX86HasRDTSCP(SB), $1
  1104  	JNE	fences
  1105  	// Instruction stream serializing RDTSCP is supported.
  1106  	// RDTSCP is supported by Intel Nehalem (2008) and
  1107  	// AMD K8 Rev. F (2006) and newer.
  1108  	RDTSCP
  1109  done:
  1110  	SHLQ	$32, DX
  1111  	ADDQ	DX, AX
  1112  	MOVQ	AX, ret+0(FP)
  1113  	RET
  1114  fences:
  1115  	// MFENCE is instruction stream serializing and flushes the
  1116  	// store buffers on AMD. The serialization semantics of LFENCE on AMD
  1117  	// are dependent on MSR C001_1029 and CPU generation.
  1118  	// LFENCE on Intel does wait for all previous instructions to have executed.
  1119  	// Intel recommends MFENCE;LFENCE in its manuals before RDTSC to have all
  1120  	// previous instructions executed and all previous loads and stores to globally visible.
  1121  	// Using MFENCE;LFENCE here aligns the serializing properties without
  1122  	// runtime detection of CPU manufacturer.
  1123  	MFENCE
  1124  	LFENCE
  1125  	RDTSC
  1126  	JMP done
  1127  
  1128  // func memhash(p unsafe.Pointer, h, s uintptr) uintptr
  1129  // hash function using AES hardware instructions
  1130  TEXT runtime·memhash<ABIInternal>(SB),NOSPLIT,$0-32
  1131  	// AX = ptr to data
  1132  	// BX = seed
  1133  	// CX = size
  1134  	CMPB	runtime·useAeshash(SB), $0
  1135  	JEQ	noaes
  1136  	JMP	aeshashbody<>(SB)
  1137  noaes:
  1138  	JMP	runtime·memhashFallback<ABIInternal>(SB)
  1139  
  1140  // func strhash(p unsafe.Pointer, h uintptr) uintptr
  1141  TEXT runtime·strhash<ABIInternal>(SB),NOSPLIT,$0-24
  1142  	// AX = ptr to string struct
  1143  	// BX = seed
  1144  	CMPB	runtime·useAeshash(SB), $0
  1145  	JEQ	noaes
  1146  	MOVQ	8(AX), CX	// length of string
  1147  	MOVQ	(AX), AX	// string data
  1148  	JMP	aeshashbody<>(SB)
  1149  noaes:
  1150  	JMP	runtime·strhashFallback<ABIInternal>(SB)
  1151  
  1152  // AX: data
  1153  // BX: hash seed
  1154  // CX: length
  1155  // At return: AX = return value
  1156  TEXT aeshashbody<>(SB),NOSPLIT,$0-0
  1157  	// Fill an SSE register with our seeds.
  1158  	MOVQ	BX, X0				// 64 bits of per-table hash seed
  1159  	PINSRW	$4, CX, X0			// 16 bits of length
  1160  	PSHUFHW $0, X0, X0			// repeat length 4 times total
  1161  	MOVO	X0, X1				// save unscrambled seed
  1162  	PXOR	runtime·aeskeysched(SB), X0	// xor in per-process seed
  1163  	AESENC	X0, X0				// scramble seed
  1164  
  1165  	CMPQ	CX, $16
  1166  	JB	aes0to15
  1167  	JE	aes16
  1168  	CMPQ	CX, $32
  1169  	JBE	aes17to32
  1170  	CMPQ	CX, $64
  1171  	JBE	aes33to64
  1172  	CMPQ	CX, $128
  1173  	JBE	aes65to128
  1174  	JMP	aes129plus
  1175  
  1176  aes0to15:
  1177  	TESTQ	CX, CX
  1178  	JE	aes0
  1179  
  1180  	ADDQ	$16, AX
  1181  	TESTW	$0xff0, AX
  1182  	JE	endofpage
  1183  
  1184  	// 16 bytes loaded at this address won't cross
  1185  	// a page boundary, so we can load it directly.
  1186  	MOVOU	-16(AX), X1
  1187  	ADDQ	CX, CX
  1188  	MOVQ	$masks<>(SB), AX
  1189  	PAND	(AX)(CX*8), X1
  1190  final1:
  1191  	PXOR	X0, X1	// xor data with seed
  1192  	AESENC	X1, X1	// scramble combo 3 times
  1193  	AESENC	X1, X1
  1194  	AESENC	X1, X1
  1195  	MOVQ	X1, AX	// return X1
  1196  	RET
  1197  
  1198  endofpage:
  1199  	// address ends in 1111xxxx. Might be up against
  1200  	// a page boundary, so load ending at last byte.
  1201  	// Then shift bytes down using pshufb.
  1202  	MOVOU	-32(AX)(CX*1), X1
  1203  	ADDQ	CX, CX
  1204  	MOVQ	$shifts<>(SB), AX
  1205  	PSHUFB	(AX)(CX*8), X1
  1206  	JMP	final1
  1207  
  1208  aes0:
  1209  	// Return scrambled input seed
  1210  	AESENC	X0, X0
  1211  	MOVQ	X0, AX	// return X0
  1212  	RET
  1213  
  1214  aes16:
  1215  	MOVOU	(AX), X1
  1216  	JMP	final1
  1217  
  1218  aes17to32:
  1219  	// make second starting seed
  1220  	PXOR	runtime·aeskeysched+16(SB), X1
  1221  	AESENC	X1, X1
  1222  
  1223  	// load data to be hashed
  1224  	MOVOU	(AX), X2
  1225  	MOVOU	-16(AX)(CX*1), X3
  1226  
  1227  	// xor with seed
  1228  	PXOR	X0, X2
  1229  	PXOR	X1, X3
  1230  
  1231  	// scramble 3 times
  1232  	AESENC	X2, X2
  1233  	AESENC	X3, X3
  1234  	AESENC	X2, X2
  1235  	AESENC	X3, X3
  1236  	AESENC	X2, X2
  1237  	AESENC	X3, X3
  1238  
  1239  	// combine results
  1240  	PXOR	X3, X2
  1241  	MOVQ	X2, AX	// return X2
  1242  	RET
  1243  
  1244  aes33to64:
  1245  	// make 3 more starting seeds
  1246  	MOVO	X1, X2
  1247  	MOVO	X1, X3
  1248  	PXOR	runtime·aeskeysched+16(SB), X1
  1249  	PXOR	runtime·aeskeysched+32(SB), X2
  1250  	PXOR	runtime·aeskeysched+48(SB), X3
  1251  	AESENC	X1, X1
  1252  	AESENC	X2, X2
  1253  	AESENC	X3, X3
  1254  
  1255  	MOVOU	(AX), X4
  1256  	MOVOU	16(AX), X5
  1257  	MOVOU	-32(AX)(CX*1), X6
  1258  	MOVOU	-16(AX)(CX*1), X7
  1259  
  1260  	PXOR	X0, X4
  1261  	PXOR	X1, X5
  1262  	PXOR	X2, X6
  1263  	PXOR	X3, X7
  1264  
  1265  	AESENC	X4, X4
  1266  	AESENC	X5, X5
  1267  	AESENC	X6, X6
  1268  	AESENC	X7, X7
  1269  
  1270  	AESENC	X4, X4
  1271  	AESENC	X5, X5
  1272  	AESENC	X6, X6
  1273  	AESENC	X7, X7
  1274  
  1275  	AESENC	X4, X4
  1276  	AESENC	X5, X5
  1277  	AESENC	X6, X6
  1278  	AESENC	X7, X7
  1279  
  1280  	PXOR	X6, X4
  1281  	PXOR	X7, X5
  1282  	PXOR	X5, X4
  1283  	MOVQ	X4, AX	// return X4
  1284  	RET
  1285  
  1286  aes65to128:
  1287  	// make 7 more starting seeds
  1288  	MOVO	X1, X2
  1289  	MOVO	X1, X3
  1290  	MOVO	X1, X4
  1291  	MOVO	X1, X5
  1292  	MOVO	X1, X6
  1293  	MOVO	X1, X7
  1294  	PXOR	runtime·aeskeysched+16(SB), X1
  1295  	PXOR	runtime·aeskeysched+32(SB), X2
  1296  	PXOR	runtime·aeskeysched+48(SB), X3
  1297  	PXOR	runtime·aeskeysched+64(SB), X4
  1298  	PXOR	runtime·aeskeysched+80(SB), X5
  1299  	PXOR	runtime·aeskeysched+96(SB), X6
  1300  	PXOR	runtime·aeskeysched+112(SB), X7
  1301  	AESENC	X1, X1
  1302  	AESENC	X2, X2
  1303  	AESENC	X3, X3
  1304  	AESENC	X4, X4
  1305  	AESENC	X5, X5
  1306  	AESENC	X6, X6
  1307  	AESENC	X7, X7
  1308  
  1309  	// load data
  1310  	MOVOU	(AX), X8
  1311  	MOVOU	16(AX), X9
  1312  	MOVOU	32(AX), X10
  1313  	MOVOU	48(AX), X11
  1314  	MOVOU	-64(AX)(CX*1), X12
  1315  	MOVOU	-48(AX)(CX*1), X13
  1316  	MOVOU	-32(AX)(CX*1), X14
  1317  	MOVOU	-16(AX)(CX*1), X15
  1318  
  1319  	// xor with seed
  1320  	PXOR	X0, X8
  1321  	PXOR	X1, X9
  1322  	PXOR	X2, X10
  1323  	PXOR	X3, X11
  1324  	PXOR	X4, X12
  1325  	PXOR	X5, X13
  1326  	PXOR	X6, X14
  1327  	PXOR	X7, X15
  1328  
  1329  	// scramble 3 times
  1330  	AESENC	X8, X8
  1331  	AESENC	X9, X9
  1332  	AESENC	X10, X10
  1333  	AESENC	X11, X11
  1334  	AESENC	X12, X12
  1335  	AESENC	X13, X13
  1336  	AESENC	X14, X14
  1337  	AESENC	X15, X15
  1338  
  1339  	AESENC	X8, X8
  1340  	AESENC	X9, X9
  1341  	AESENC	X10, X10
  1342  	AESENC	X11, X11
  1343  	AESENC	X12, X12
  1344  	AESENC	X13, X13
  1345  	AESENC	X14, X14
  1346  	AESENC	X15, X15
  1347  
  1348  	AESENC	X8, X8
  1349  	AESENC	X9, X9
  1350  	AESENC	X10, X10
  1351  	AESENC	X11, X11
  1352  	AESENC	X12, X12
  1353  	AESENC	X13, X13
  1354  	AESENC	X14, X14
  1355  	AESENC	X15, X15
  1356  
  1357  	// combine results
  1358  	PXOR	X12, X8
  1359  	PXOR	X13, X9
  1360  	PXOR	X14, X10
  1361  	PXOR	X15, X11
  1362  	PXOR	X10, X8
  1363  	PXOR	X11, X9
  1364  	PXOR	X9, X8
  1365  	// X15 must be zero on return
  1366  	PXOR	X15, X15
  1367  	MOVQ	X8, AX	// return X8
  1368  	RET
  1369  
  1370  aes129plus:
  1371  	// make 7 more starting seeds
  1372  	MOVO	X1, X2
  1373  	MOVO	X1, X3
  1374  	MOVO	X1, X4
  1375  	MOVO	X1, X5
  1376  	MOVO	X1, X6
  1377  	MOVO	X1, X7
  1378  	PXOR	runtime·aeskeysched+16(SB), X1
  1379  	PXOR	runtime·aeskeysched+32(SB), X2
  1380  	PXOR	runtime·aeskeysched+48(SB), X3
  1381  	PXOR	runtime·aeskeysched+64(SB), X4
  1382  	PXOR	runtime·aeskeysched+80(SB), X5
  1383  	PXOR	runtime·aeskeysched+96(SB), X6
  1384  	PXOR	runtime·aeskeysched+112(SB), X7
  1385  	AESENC	X1, X1
  1386  	AESENC	X2, X2
  1387  	AESENC	X3, X3
  1388  	AESENC	X4, X4
  1389  	AESENC	X5, X5
  1390  	AESENC	X6, X6
  1391  	AESENC	X7, X7
  1392  
  1393  	// start with last (possibly overlapping) block
  1394  	MOVOU	-128(AX)(CX*1), X8
  1395  	MOVOU	-112(AX)(CX*1), X9
  1396  	MOVOU	-96(AX)(CX*1), X10
  1397  	MOVOU	-80(AX)(CX*1), X11
  1398  	MOVOU	-64(AX)(CX*1), X12
  1399  	MOVOU	-48(AX)(CX*1), X13
  1400  	MOVOU	-32(AX)(CX*1), X14
  1401  	MOVOU	-16(AX)(CX*1), X15
  1402  
  1403  	// xor in seed
  1404  	PXOR	X0, X8
  1405  	PXOR	X1, X9
  1406  	PXOR	X2, X10
  1407  	PXOR	X3, X11
  1408  	PXOR	X4, X12
  1409  	PXOR	X5, X13
  1410  	PXOR	X6, X14
  1411  	PXOR	X7, X15
  1412  
  1413  	// compute number of remaining 128-byte blocks
  1414  	DECQ	CX
  1415  	SHRQ	$7, CX
  1416  
  1417  aesloop:
  1418  	// scramble state
  1419  	AESENC	X8, X8
  1420  	AESENC	X9, X9
  1421  	AESENC	X10, X10
  1422  	AESENC	X11, X11
  1423  	AESENC	X12, X12
  1424  	AESENC	X13, X13
  1425  	AESENC	X14, X14
  1426  	AESENC	X15, X15
  1427  
  1428  	// scramble state, xor in a block
  1429  	MOVOU	(AX), X0
  1430  	MOVOU	16(AX), X1
  1431  	MOVOU	32(AX), X2
  1432  	MOVOU	48(AX), X3
  1433  	AESENC	X0, X8
  1434  	AESENC	X1, X9
  1435  	AESENC	X2, X10
  1436  	AESENC	X3, X11
  1437  	MOVOU	64(AX), X4
  1438  	MOVOU	80(AX), X5
  1439  	MOVOU	96(AX), X6
  1440  	MOVOU	112(AX), X7
  1441  	AESENC	X4, X12
  1442  	AESENC	X5, X13
  1443  	AESENC	X6, X14
  1444  	AESENC	X7, X15
  1445  
  1446  	ADDQ	$128, AX
  1447  	DECQ	CX
  1448  	JNE	aesloop
  1449  
  1450  	// 3 more scrambles to finish
  1451  	AESENC	X8, X8
  1452  	AESENC	X9, X9
  1453  	AESENC	X10, X10
  1454  	AESENC	X11, X11
  1455  	AESENC	X12, X12
  1456  	AESENC	X13, X13
  1457  	AESENC	X14, X14
  1458  	AESENC	X15, X15
  1459  	AESENC	X8, X8
  1460  	AESENC	X9, X9
  1461  	AESENC	X10, X10
  1462  	AESENC	X11, X11
  1463  	AESENC	X12, X12
  1464  	AESENC	X13, X13
  1465  	AESENC	X14, X14
  1466  	AESENC	X15, X15
  1467  	AESENC	X8, X8
  1468  	AESENC	X9, X9
  1469  	AESENC	X10, X10
  1470  	AESENC	X11, X11
  1471  	AESENC	X12, X12
  1472  	AESENC	X13, X13
  1473  	AESENC	X14, X14
  1474  	AESENC	X15, X15
  1475  
  1476  	PXOR	X12, X8
  1477  	PXOR	X13, X9
  1478  	PXOR	X14, X10
  1479  	PXOR	X15, X11
  1480  	PXOR	X10, X8
  1481  	PXOR	X11, X9
  1482  	PXOR	X9, X8
  1483  	// X15 must be zero on return
  1484  	PXOR	X15, X15
  1485  	MOVQ	X8, AX	// return X8
  1486  	RET
  1487  
  1488  // func memhash32(p unsafe.Pointer, h uintptr) uintptr
  1489  // ABIInternal for performance.
  1490  TEXT runtime·memhash32<ABIInternal>(SB),NOSPLIT,$0-24
  1491  	// AX = ptr to data
  1492  	// BX = seed
  1493  	CMPB	runtime·useAeshash(SB), $0
  1494  	JEQ	noaes
  1495  	MOVQ	BX, X0	// X0 = seed
  1496  	PINSRD	$2, (AX), X0	// data
  1497  	AESENC	runtime·aeskeysched+0(SB), X0
  1498  	AESENC	runtime·aeskeysched+16(SB), X0
  1499  	AESENC	runtime·aeskeysched+32(SB), X0
  1500  	MOVQ	X0, AX	// return X0
  1501  	RET
  1502  noaes:
  1503  	JMP	runtime·memhash32Fallback<ABIInternal>(SB)
  1504  
  1505  // func memhash64(p unsafe.Pointer, h uintptr) uintptr
  1506  // ABIInternal for performance.
  1507  TEXT runtime·memhash64<ABIInternal>(SB),NOSPLIT,$0-24
  1508  	// AX = ptr to data
  1509  	// BX = seed
  1510  	CMPB	runtime·useAeshash(SB), $0
  1511  	JEQ	noaes
  1512  	MOVQ	BX, X0	// X0 = seed
  1513  	PINSRQ	$1, (AX), X0	// data
  1514  	AESENC	runtime·aeskeysched+0(SB), X0
  1515  	AESENC	runtime·aeskeysched+16(SB), X0
  1516  	AESENC	runtime·aeskeysched+32(SB), X0
  1517  	MOVQ	X0, AX	// return X0
  1518  	RET
  1519  noaes:
  1520  	JMP	runtime·memhash64Fallback<ABIInternal>(SB)
  1521  
  1522  // simple mask to get rid of data in the high part of the register.
  1523  DATA masks<>+0x00(SB)/8, $0x0000000000000000
  1524  DATA masks<>+0x08(SB)/8, $0x0000000000000000
  1525  DATA masks<>+0x10(SB)/8, $0x00000000000000ff
  1526  DATA masks<>+0x18(SB)/8, $0x0000000000000000
  1527  DATA masks<>+0x20(SB)/8, $0x000000000000ffff
  1528  DATA masks<>+0x28(SB)/8, $0x0000000000000000
  1529  DATA masks<>+0x30(SB)/8, $0x0000000000ffffff
  1530  DATA masks<>+0x38(SB)/8, $0x0000000000000000
  1531  DATA masks<>+0x40(SB)/8, $0x00000000ffffffff
  1532  DATA masks<>+0x48(SB)/8, $0x0000000000000000
  1533  DATA masks<>+0x50(SB)/8, $0x000000ffffffffff
  1534  DATA masks<>+0x58(SB)/8, $0x0000000000000000
  1535  DATA masks<>+0x60(SB)/8, $0x0000ffffffffffff
  1536  DATA masks<>+0x68(SB)/8, $0x0000000000000000
  1537  DATA masks<>+0x70(SB)/8, $0x00ffffffffffffff
  1538  DATA masks<>+0x78(SB)/8, $0x0000000000000000
  1539  DATA masks<>+0x80(SB)/8, $0xffffffffffffffff
  1540  DATA masks<>+0x88(SB)/8, $0x0000000000000000
  1541  DATA masks<>+0x90(SB)/8, $0xffffffffffffffff
  1542  DATA masks<>+0x98(SB)/8, $0x00000000000000ff
  1543  DATA masks<>+0xa0(SB)/8, $0xffffffffffffffff
  1544  DATA masks<>+0xa8(SB)/8, $0x000000000000ffff
  1545  DATA masks<>+0xb0(SB)/8, $0xffffffffffffffff
  1546  DATA masks<>+0xb8(SB)/8, $0x0000000000ffffff
  1547  DATA masks<>+0xc0(SB)/8, $0xffffffffffffffff
  1548  DATA masks<>+0xc8(SB)/8, $0x00000000ffffffff
  1549  DATA masks<>+0xd0(SB)/8, $0xffffffffffffffff
  1550  DATA masks<>+0xd8(SB)/8, $0x000000ffffffffff
  1551  DATA masks<>+0xe0(SB)/8, $0xffffffffffffffff
  1552  DATA masks<>+0xe8(SB)/8, $0x0000ffffffffffff
  1553  DATA masks<>+0xf0(SB)/8, $0xffffffffffffffff
  1554  DATA masks<>+0xf8(SB)/8, $0x00ffffffffffffff
  1555  GLOBL masks<>(SB),RODATA,$256
  1556  
  1557  // func checkASM() bool
  1558  TEXT ·checkASM(SB),NOSPLIT,$0-1
  1559  	// check that masks<>(SB) and shifts<>(SB) are aligned to 16-byte
  1560  	MOVQ	$masks<>(SB), AX
  1561  	MOVQ	$shifts<>(SB), BX
  1562  	ORQ	BX, AX
  1563  	TESTQ	$15, AX
  1564  	SETEQ	ret+0(FP)
  1565  	RET
  1566  
  1567  // these are arguments to pshufb. They move data down from
  1568  // the high bytes of the register to the low bytes of the register.
  1569  // index is how many bytes to move.
  1570  DATA shifts<>+0x00(SB)/8, $0x0000000000000000
  1571  DATA shifts<>+0x08(SB)/8, $0x0000000000000000
  1572  DATA shifts<>+0x10(SB)/8, $0xffffffffffffff0f
  1573  DATA shifts<>+0x18(SB)/8, $0xffffffffffffffff
  1574  DATA shifts<>+0x20(SB)/8, $0xffffffffffff0f0e
  1575  DATA shifts<>+0x28(SB)/8, $0xffffffffffffffff
  1576  DATA shifts<>+0x30(SB)/8, $0xffffffffff0f0e0d
  1577  DATA shifts<>+0x38(SB)/8, $0xffffffffffffffff
  1578  DATA shifts<>+0x40(SB)/8, $0xffffffff0f0e0d0c
  1579  DATA shifts<>+0x48(SB)/8, $0xffffffffffffffff
  1580  DATA shifts<>+0x50(SB)/8, $0xffffff0f0e0d0c0b
  1581  DATA shifts<>+0x58(SB)/8, $0xffffffffffffffff
  1582  DATA shifts<>+0x60(SB)/8, $0xffff0f0e0d0c0b0a
  1583  DATA shifts<>+0x68(SB)/8, $0xffffffffffffffff
  1584  DATA shifts<>+0x70(SB)/8, $0xff0f0e0d0c0b0a09
  1585  DATA shifts<>+0x78(SB)/8, $0xffffffffffffffff
  1586  DATA shifts<>+0x80(SB)/8, $0x0f0e0d0c0b0a0908
  1587  DATA shifts<>+0x88(SB)/8, $0xffffffffffffffff
  1588  DATA shifts<>+0x90(SB)/8, $0x0e0d0c0b0a090807
  1589  DATA shifts<>+0x98(SB)/8, $0xffffffffffffff0f
  1590  DATA shifts<>+0xa0(SB)/8, $0x0d0c0b0a09080706
  1591  DATA shifts<>+0xa8(SB)/8, $0xffffffffffff0f0e
  1592  DATA shifts<>+0xb0(SB)/8, $0x0c0b0a0908070605
  1593  DATA shifts<>+0xb8(SB)/8, $0xffffffffff0f0e0d
  1594  DATA shifts<>+0xc0(SB)/8, $0x0b0a090807060504
  1595  DATA shifts<>+0xc8(SB)/8, $0xffffffff0f0e0d0c
  1596  DATA shifts<>+0xd0(SB)/8, $0x0a09080706050403
  1597  DATA shifts<>+0xd8(SB)/8, $0xffffff0f0e0d0c0b
  1598  DATA shifts<>+0xe0(SB)/8, $0x0908070605040302
  1599  DATA shifts<>+0xe8(SB)/8, $0xffff0f0e0d0c0b0a
  1600  DATA shifts<>+0xf0(SB)/8, $0x0807060504030201
  1601  DATA shifts<>+0xf8(SB)/8, $0xff0f0e0d0c0b0a09
  1602  GLOBL shifts<>(SB),RODATA,$256
  1603  
  1604  TEXT runtime·return0(SB), NOSPLIT, $0
  1605  	MOVL	$0, AX
  1606  	RET
  1607  
  1608  
  1609  // Called from cgo wrappers, this function returns g->m->curg.stack.hi.
  1610  // Must obey the gcc calling convention.
  1611  TEXT _cgo_topofstack(SB),NOSPLIT,$0
  1612  	get_tls(CX)
  1613  	MOVQ	g(CX), AX
  1614  	MOVQ	g_m(AX), AX
  1615  	MOVQ	m_curg(AX), AX
  1616  	MOVQ	(g_stack+stack_hi)(AX), AX
  1617  	RET
  1618  
  1619  // The top-most function running on a goroutine
  1620  // returns to goexit+PCQuantum.
  1621  TEXT runtime·goexit(SB),NOSPLIT|TOPFRAME|NOFRAME,$0-0
  1622  	BYTE	$0x90	// NOP
  1623  	CALL	runtime·goexit1(SB)	// does not return
  1624  	// traceback from goexit1 must hit code range of goexit
  1625  	BYTE	$0x90	// NOP
  1626  
  1627  // This is called from .init_array and follows the platform, not Go, ABI.
  1628  TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
  1629  	PUSHQ	R15 // The access to global variables below implicitly uses R15, which is callee-save
  1630  	MOVQ	runtime·lastmoduledatap(SB), AX
  1631  	MOVQ	DI, moduledata_next(AX)
  1632  	MOVQ	DI, runtime·lastmoduledatap(SB)
  1633  	POPQ	R15
  1634  	RET
  1635  
  1636  // Initialize special registers then jump to sigpanic.
  1637  // This function is injected from the signal handler for panicking
  1638  // signals. It is quite painful to set X15 in the signal context,
  1639  // so we do it here.
  1640  TEXT ·sigpanic0(SB),NOSPLIT,$0-0
  1641  	get_tls(R14)
  1642  	MOVQ	g(R14), R14
  1643  #ifndef GOOS_plan9
  1644  	XORPS	X15, X15
  1645  #endif
  1646  	JMP	·sigpanic<ABIInternal>(SB)
  1647  
  1648  // gcWriteBarrier informs the GC about heap pointer writes.
  1649  //
  1650  // gcWriteBarrier returns space in a write barrier buffer which
  1651  // should be filled in by the caller.
  1652  // gcWriteBarrier does NOT follow the Go ABI. It accepts the
  1653  // number of bytes of buffer needed in R11, and returns a pointer
  1654  // to the buffer space in R11.
  1655  // It clobbers FLAGS. It does not clobber any general-purpose registers,
  1656  // but may clobber others (e.g., SSE registers).
  1657  // Typical use would be, when doing *(CX+88) = AX
  1658  //     CMPL    $0, runtime.writeBarrier(SB)
  1659  //     JEQ     dowrite
  1660  //     CALL    runtime.gcBatchBarrier2(SB)
  1661  //     MOVQ    AX, (R11)
  1662  //     MOVQ    88(CX), DX
  1663  //     MOVQ    DX, 8(R11)
  1664  // dowrite:
  1665  //     MOVQ    AX, 88(CX)
  1666  TEXT gcWriteBarrier<>(SB),NOSPLIT,$112
  1667  	// Save the registers clobbered by the fast path. This is slightly
  1668  	// faster than having the caller spill these.
  1669  	MOVQ	R12, 96(SP)
  1670  	MOVQ	R13, 104(SP)
  1671  retry:
  1672  	// TODO: Consider passing g.m.p in as an argument so they can be shared
  1673  	// across a sequence of write barriers.
  1674  	MOVQ	g_m(R14), R13
  1675  	MOVQ	m_p(R13), R13
  1676  	// Get current buffer write position.
  1677  	MOVQ	(p_wbBuf+wbBuf_next)(R13), R12	// original next position
  1678  	ADDQ	R11, R12			// new next position
  1679  	// Is the buffer full?
  1680  	CMPQ	R12, (p_wbBuf+wbBuf_end)(R13)
  1681  	JA	flush
  1682  	// Commit to the larger buffer.
  1683  	MOVQ	R12, (p_wbBuf+wbBuf_next)(R13)
  1684  	// Make return value (the original next position)
  1685  	SUBQ	R11, R12
  1686  	MOVQ	R12, R11
  1687  	// Restore registers.
  1688  	MOVQ	96(SP), R12
  1689  	MOVQ	104(SP), R13
  1690  	RET
  1691  
  1692  flush:
  1693  	// Save all general purpose registers since these could be
  1694  	// clobbered by wbBufFlush and were not saved by the caller.
  1695  	// It is possible for wbBufFlush to clobber other registers
  1696  	// (e.g., SSE registers), but the compiler takes care of saving
  1697  	// those in the caller if necessary. This strikes a balance
  1698  	// with registers that are likely to be used.
  1699  	//
  1700  	// We don't have type information for these, but all code under
  1701  	// here is NOSPLIT, so nothing will observe these.
  1702  	//
  1703  	// TODO: We could strike a different balance; e.g., saving X0
  1704  	// and not saving GP registers that are less likely to be used.
  1705  	MOVQ	DI, 0(SP)
  1706  	MOVQ	AX, 8(SP)
  1707  	MOVQ	BX, 16(SP)
  1708  	MOVQ	CX, 24(SP)
  1709  	MOVQ	DX, 32(SP)
  1710  	// DI already saved
  1711  	MOVQ	SI, 40(SP)
  1712  	MOVQ	BP, 48(SP)
  1713  	MOVQ	R8, 56(SP)
  1714  	MOVQ	R9, 64(SP)
  1715  	MOVQ	R10, 72(SP)
  1716  	MOVQ	R11, 80(SP)
  1717  	// R12 already saved
  1718  	// R13 already saved
  1719  	// R14 is g
  1720  	MOVQ	R15, 88(SP)
  1721  
  1722  	CALL	runtime·wbBufFlush(SB)
  1723  
  1724  	MOVQ	0(SP), DI
  1725  	MOVQ	8(SP), AX
  1726  	MOVQ	16(SP), BX
  1727  	MOVQ	24(SP), CX
  1728  	MOVQ	32(SP), DX
  1729  	MOVQ	40(SP), SI
  1730  	MOVQ	48(SP), BP
  1731  	MOVQ	56(SP), R8
  1732  	MOVQ	64(SP), R9
  1733  	MOVQ	72(SP), R10
  1734  	MOVQ	80(SP), R11
  1735  	MOVQ	88(SP), R15
  1736  	JMP	retry
  1737  
  1738  TEXT runtime·gcWriteBarrier1<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1739  	MOVL   $8, R11
  1740  	JMP     gcWriteBarrier<>(SB)
  1741  TEXT runtime·gcWriteBarrier2<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1742  	MOVL   $16, R11
  1743  	JMP     gcWriteBarrier<>(SB)
  1744  TEXT runtime·gcWriteBarrier3<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1745  	MOVL   $24, R11
  1746  	JMP     gcWriteBarrier<>(SB)
  1747  TEXT runtime·gcWriteBarrier4<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1748  	MOVL   $32, R11
  1749  	JMP     gcWriteBarrier<>(SB)
  1750  TEXT runtime·gcWriteBarrier5<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1751  	MOVL   $40, R11
  1752  	JMP     gcWriteBarrier<>(SB)
  1753  TEXT runtime·gcWriteBarrier6<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1754  	MOVL   $48, R11
  1755  	JMP     gcWriteBarrier<>(SB)
  1756  TEXT runtime·gcWriteBarrier7<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1757  	MOVL   $56, R11
  1758  	JMP     gcWriteBarrier<>(SB)
  1759  TEXT runtime·gcWriteBarrier8<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  1760  	MOVL   $64, R11
  1761  	JMP     gcWriteBarrier<>(SB)
  1762  
  1763  DATA	debugCallFrameTooLarge<>+0x00(SB)/20, $"call frame too large"
  1764  GLOBL	debugCallFrameTooLarge<>(SB), RODATA, $20	// Size duplicated below
  1765  
  1766  // debugCallV2 is the entry point for debugger-injected function
  1767  // calls on running goroutines. It informs the runtime that a
  1768  // debug call has been injected and creates a call frame for the
  1769  // debugger to fill in.
  1770  //
  1771  // To inject a function call, a debugger should:
  1772  // 1. Check that the goroutine is in state _Grunning and that
  1773  //    there are at least 256 bytes free on the stack.
  1774  // 2. Push the current PC on the stack (updating SP).
  1775  // 3. Write the desired argument frame size at SP-16 (using the SP
  1776  //    after step 2).
  1777  // 4. Save all machine registers (including flags and XMM registers)
  1778  //    so they can be restored later by the debugger.
  1779  // 5. Set the PC to debugCallV2 and resume execution.
  1780  //
  1781  // If the goroutine is in state _Grunnable, then it's not generally
  1782  // safe to inject a call because it may return out via other runtime
  1783  // operations. Instead, the debugger should unwind the stack to find
  1784  // the return to non-runtime code, add a temporary breakpoint there,
  1785  // and inject the call once that breakpoint is hit.
  1786  //
  1787  // If the goroutine is in any other state, it's not safe to inject a call.
  1788  //
  1789  // This function communicates back to the debugger by setting R12 and
  1790  // invoking INT3 to raise a breakpoint signal. See the comments in the
  1791  // implementation for the protocol the debugger is expected to
  1792  // follow. InjectDebugCall in the runtime tests demonstrates this protocol.
  1793  //
  1794  // The debugger must ensure that any pointers passed to the function
  1795  // obey escape analysis requirements. Specifically, it must not pass
  1796  // a stack pointer to an escaping argument. debugCallV2 cannot check
  1797  // this invariant.
  1798  //
  1799  // This is ABIInternal because Go code injects its PC directly into new
  1800  // goroutine stacks.
  1801  TEXT runtime·debugCallV2<ABIInternal>(SB),NOSPLIT,$152-0
  1802  	// Save all registers that may contain pointers so they can be
  1803  	// conservatively scanned.
  1804  	//
  1805  	// We can't do anything that might clobber any of these
  1806  	// registers before this.
  1807  	MOVQ	R15, r15-(14*8+8)(SP)
  1808  	MOVQ	R14, r14-(13*8+8)(SP)
  1809  	MOVQ	R13, r13-(12*8+8)(SP)
  1810  	MOVQ	R12, r12-(11*8+8)(SP)
  1811  	MOVQ	R11, r11-(10*8+8)(SP)
  1812  	MOVQ	R10, r10-(9*8+8)(SP)
  1813  	MOVQ	R9, r9-(8*8+8)(SP)
  1814  	MOVQ	R8, r8-(7*8+8)(SP)
  1815  	MOVQ	DI, di-(6*8+8)(SP)
  1816  	MOVQ	SI, si-(5*8+8)(SP)
  1817  	MOVQ	BP, bp-(4*8+8)(SP)
  1818  	MOVQ	BX, bx-(3*8+8)(SP)
  1819  	MOVQ	DX, dx-(2*8+8)(SP)
  1820  	// Save the frame size before we clobber it. Either of the last
  1821  	// saves could clobber this depending on whether there's a saved BP.
  1822  	MOVQ	frameSize-24(FP), DX	// aka -16(RSP) before prologue
  1823  	MOVQ	CX, cx-(1*8+8)(SP)
  1824  	MOVQ	AX, ax-(0*8+8)(SP)
  1825  
  1826  	// Save the argument frame size.
  1827  	MOVQ	DX, frameSize-128(SP)
  1828  
  1829  	// Perform a safe-point check.
  1830  	MOVQ	retpc-8(FP), AX	// Caller's PC
  1831  	MOVQ	AX, 0(SP)
  1832  	CALL	runtime·debugCallCheck(SB)
  1833  	MOVQ	8(SP), AX
  1834  	TESTQ	AX, AX
  1835  	JZ	good
  1836  	// The safety check failed. Put the reason string at the top
  1837  	// of the stack.
  1838  	MOVQ	AX, 0(SP)
  1839  	MOVQ	16(SP), AX
  1840  	MOVQ	AX, 8(SP)
  1841  	// Set R12 to 8 and invoke INT3. The debugger should get the
  1842  	// reason a call can't be injected from the top of the stack
  1843  	// and resume execution.
  1844  	MOVQ	$8, R12
  1845  	BYTE	$0xcc
  1846  	JMP	restore
  1847  
  1848  good:
  1849  	// Registers are saved and it's safe to make a call.
  1850  	// Open up a call frame, moving the stack if necessary.
  1851  	//
  1852  	// Once the frame is allocated, this will set R12 to 0 and
  1853  	// invoke INT3. The debugger should write the argument
  1854  	// frame for the call at SP, set up argument registers, push
  1855  	// the trapping PC on the stack, set the PC to the function to
  1856  	// call, set RDX to point to the closure (if a closure call),
  1857  	// and resume execution.
  1858  	//
  1859  	// If the function returns, this will set R12 to 1 and invoke
  1860  	// INT3. The debugger can then inspect any return value saved
  1861  	// on the stack at SP and in registers and resume execution again.
  1862  	//
  1863  	// If the function panics, this will set R12 to 2 and invoke INT3.
  1864  	// The interface{} value of the panic will be at SP. The debugger
  1865  	// can inspect the panic value and resume execution again.
  1866  #define DEBUG_CALL_DISPATCH(NAME,MAXSIZE)	\
  1867  	CMPQ	AX, $MAXSIZE;			\
  1868  	JA	5(PC);				\
  1869  	MOVQ	$NAME(SB), AX;			\
  1870  	MOVQ	AX, 0(SP);			\
  1871  	CALL	runtime·debugCallWrap(SB);	\
  1872  	JMP	restore
  1873  
  1874  	MOVQ	frameSize-128(SP), AX
  1875  	DEBUG_CALL_DISPATCH(debugCall32<>, 32)
  1876  	DEBUG_CALL_DISPATCH(debugCall64<>, 64)
  1877  	DEBUG_CALL_DISPATCH(debugCall128<>, 128)
  1878  	DEBUG_CALL_DISPATCH(debugCall256<>, 256)
  1879  	DEBUG_CALL_DISPATCH(debugCall512<>, 512)
  1880  	DEBUG_CALL_DISPATCH(debugCall1024<>, 1024)
  1881  	DEBUG_CALL_DISPATCH(debugCall2048<>, 2048)
  1882  	DEBUG_CALL_DISPATCH(debugCall4096<>, 4096)
  1883  	DEBUG_CALL_DISPATCH(debugCall8192<>, 8192)
  1884  	DEBUG_CALL_DISPATCH(debugCall16384<>, 16384)
  1885  	DEBUG_CALL_DISPATCH(debugCall32768<>, 32768)
  1886  	DEBUG_CALL_DISPATCH(debugCall65536<>, 65536)
  1887  	// The frame size is too large. Report the error.
  1888  	MOVQ	$debugCallFrameTooLarge<>(SB), AX
  1889  	MOVQ	AX, 0(SP)
  1890  	MOVQ	$20, 8(SP) // length of debugCallFrameTooLarge string
  1891  	MOVQ	$8, R12
  1892  	BYTE	$0xcc
  1893  	JMP	restore
  1894  
  1895  restore:
  1896  	// Calls and failures resume here.
  1897  	//
  1898  	// Set R12 to 16 and invoke INT3. The debugger should restore
  1899  	// all registers except RIP and RSP and resume execution.
  1900  	MOVQ	$16, R12
  1901  	BYTE	$0xcc
  1902  	// We must not modify flags after this point.
  1903  
  1904  	// Restore pointer-containing registers, which may have been
  1905  	// modified from the debugger's copy by stack copying.
  1906  	MOVQ	ax-(0*8+8)(SP), AX
  1907  	MOVQ	cx-(1*8+8)(SP), CX
  1908  	MOVQ	dx-(2*8+8)(SP), DX
  1909  	MOVQ	bx-(3*8+8)(SP), BX
  1910  	MOVQ	bp-(4*8+8)(SP), BP
  1911  	MOVQ	si-(5*8+8)(SP), SI
  1912  	MOVQ	di-(6*8+8)(SP), DI
  1913  	MOVQ	r8-(7*8+8)(SP), R8
  1914  	MOVQ	r9-(8*8+8)(SP), R9
  1915  	MOVQ	r10-(9*8+8)(SP), R10
  1916  	MOVQ	r11-(10*8+8)(SP), R11
  1917  	MOVQ	r12-(11*8+8)(SP), R12
  1918  	MOVQ	r13-(12*8+8)(SP), R13
  1919  	MOVQ	r14-(13*8+8)(SP), R14
  1920  	MOVQ	r15-(14*8+8)(SP), R15
  1921  
  1922  	RET
  1923  
  1924  // runtime.debugCallCheck assumes that functions defined with the
  1925  // DEBUG_CALL_FN macro are safe points to inject calls.
  1926  #define DEBUG_CALL_FN(NAME,MAXSIZE)		\
  1927  TEXT NAME(SB),WRAPPER,$MAXSIZE-0;		\
  1928  	NO_LOCAL_POINTERS;			\
  1929  	MOVQ	$0, R12;				\
  1930  	BYTE	$0xcc;				\
  1931  	MOVQ	$1, R12;				\
  1932  	BYTE	$0xcc;				\
  1933  	RET
  1934  DEBUG_CALL_FN(debugCall32<>, 32)
  1935  DEBUG_CALL_FN(debugCall64<>, 64)
  1936  DEBUG_CALL_FN(debugCall128<>, 128)
  1937  DEBUG_CALL_FN(debugCall256<>, 256)
  1938  DEBUG_CALL_FN(debugCall512<>, 512)
  1939  DEBUG_CALL_FN(debugCall1024<>, 1024)
  1940  DEBUG_CALL_FN(debugCall2048<>, 2048)
  1941  DEBUG_CALL_FN(debugCall4096<>, 4096)
  1942  DEBUG_CALL_FN(debugCall8192<>, 8192)
  1943  DEBUG_CALL_FN(debugCall16384<>, 16384)
  1944  DEBUG_CALL_FN(debugCall32768<>, 32768)
  1945  DEBUG_CALL_FN(debugCall65536<>, 65536)
  1946  
  1947  // func debugCallPanicked(val interface{})
  1948  TEXT runtime·debugCallPanicked(SB),NOSPLIT,$16-16
  1949  	// Copy the panic value to the top of stack.
  1950  	MOVQ	val_type+0(FP), AX
  1951  	MOVQ	AX, 0(SP)
  1952  	MOVQ	val_data+8(FP), AX
  1953  	MOVQ	AX, 8(SP)
  1954  	MOVQ	$2, R12
  1955  	BYTE	$0xcc
  1956  	RET
  1957  
  1958  // Note: these functions use a special calling convention to save generated code space.
  1959  // Arguments are passed in registers, but the space for those arguments are allocated
  1960  // in the caller's stack frame. These stubs write the args into that stack space and
  1961  // then tail call to the corresponding runtime handler.
  1962  // The tail call makes these stubs disappear in backtraces.
  1963  // Defined as ABIInternal since they do not use the stack-based Go ABI.
  1964  TEXT runtime·panicIndex<ABIInternal>(SB),NOSPLIT,$0-16
  1965  	MOVQ	CX, BX
  1966  	JMP	runtime·goPanicIndex<ABIInternal>(SB)
  1967  TEXT runtime·panicIndexU<ABIInternal>(SB),NOSPLIT,$0-16
  1968  	MOVQ	CX, BX
  1969  	JMP	runtime·goPanicIndexU<ABIInternal>(SB)
  1970  TEXT runtime·panicSliceAlen<ABIInternal>(SB),NOSPLIT,$0-16
  1971  	MOVQ	CX, AX
  1972  	MOVQ	DX, BX
  1973  	JMP	runtime·goPanicSliceAlen<ABIInternal>(SB)
  1974  TEXT runtime·panicSliceAlenU<ABIInternal>(SB),NOSPLIT,$0-16
  1975  	MOVQ	CX, AX
  1976  	MOVQ	DX, BX
  1977  	JMP	runtime·goPanicSliceAlenU<ABIInternal>(SB)
  1978  TEXT runtime·panicSliceAcap<ABIInternal>(SB),NOSPLIT,$0-16
  1979  	MOVQ	CX, AX
  1980  	MOVQ	DX, BX
  1981  	JMP	runtime·goPanicSliceAcap<ABIInternal>(SB)
  1982  TEXT runtime·panicSliceAcapU<ABIInternal>(SB),NOSPLIT,$0-16
  1983  	MOVQ	CX, AX
  1984  	MOVQ	DX, BX
  1985  	JMP	runtime·goPanicSliceAcapU<ABIInternal>(SB)
  1986  TEXT runtime·panicSliceB<ABIInternal>(SB),NOSPLIT,$0-16
  1987  	MOVQ	CX, BX
  1988  	JMP	runtime·goPanicSliceB<ABIInternal>(SB)
  1989  TEXT runtime·panicSliceBU<ABIInternal>(SB),NOSPLIT,$0-16
  1990  	MOVQ	CX, BX
  1991  	JMP	runtime·goPanicSliceBU<ABIInternal>(SB)
  1992  TEXT runtime·panicSlice3Alen<ABIInternal>(SB),NOSPLIT,$0-16
  1993  	MOVQ	DX, AX
  1994  	JMP	runtime·goPanicSlice3Alen<ABIInternal>(SB)
  1995  TEXT runtime·panicSlice3AlenU<ABIInternal>(SB),NOSPLIT,$0-16
  1996  	MOVQ	DX, AX
  1997  	JMP	runtime·goPanicSlice3AlenU<ABIInternal>(SB)
  1998  TEXT runtime·panicSlice3Acap<ABIInternal>(SB),NOSPLIT,$0-16
  1999  	MOVQ	DX, AX
  2000  	JMP	runtime·goPanicSlice3Acap<ABIInternal>(SB)
  2001  TEXT runtime·panicSlice3AcapU<ABIInternal>(SB),NOSPLIT,$0-16
  2002  	MOVQ	DX, AX
  2003  	JMP	runtime·goPanicSlice3AcapU<ABIInternal>(SB)
  2004  TEXT runtime·panicSlice3B<ABIInternal>(SB),NOSPLIT,$0-16
  2005  	MOVQ	CX, AX
  2006  	MOVQ	DX, BX
  2007  	JMP	runtime·goPanicSlice3B<ABIInternal>(SB)
  2008  TEXT runtime·panicSlice3BU<ABIInternal>(SB),NOSPLIT,$0-16
  2009  	MOVQ	CX, AX
  2010  	MOVQ	DX, BX
  2011  	JMP	runtime·goPanicSlice3BU<ABIInternal>(SB)
  2012  TEXT runtime·panicSlice3C<ABIInternal>(SB),NOSPLIT,$0-16
  2013  	MOVQ	CX, BX
  2014  	JMP	runtime·goPanicSlice3C<ABIInternal>(SB)
  2015  TEXT runtime·panicSlice3CU<ABIInternal>(SB),NOSPLIT,$0-16
  2016  	MOVQ	CX, BX
  2017  	JMP	runtime·goPanicSlice3CU<ABIInternal>(SB)
  2018  TEXT runtime·panicSliceConvert<ABIInternal>(SB),NOSPLIT,$0-16
  2019  	MOVQ	DX, AX
  2020  	JMP	runtime·goPanicSliceConvert<ABIInternal>(SB)
  2021  
  2022  #ifdef GOOS_android
  2023  // Use the free TLS_SLOT_APP slot #2 on Android Q.
  2024  // Earlier androids are set up in gcc_android.c.
  2025  DATA runtime·tls_g+0(SB)/8, $16
  2026  GLOBL runtime·tls_g+0(SB), NOPTR, $8
  2027  #endif
  2028  #ifdef GOOS_windows
  2029  GLOBL runtime·tls_g+0(SB), NOPTR, $8
  2030  #endif
  2031  
  2032  // The compiler and assembler's -spectre=ret mode rewrites
  2033  // all indirect CALL AX / JMP AX instructions to be
  2034  // CALL retpolineAX / JMP retpolineAX.
  2035  // See https://support.google.com/faqs/answer/7625886.
  2036  #define RETPOLINE(reg) \
  2037  	/*   CALL setup */     BYTE $0xE8; BYTE $(2+2); BYTE $0; BYTE $0; BYTE $0;	\
  2038  	/* nospec: */									\
  2039  	/*   PAUSE */           BYTE $0xF3; BYTE $0x90;					\
  2040  	/*   JMP nospec */      BYTE $0xEB; BYTE $-(2+2);				\
  2041  	/* setup: */									\
  2042  	/*   MOVQ AX, 0(SP) */  BYTE $0x48|((reg&8)>>1); BYTE $0x89;			\
  2043  	                        BYTE $0x04|((reg&7)<<3); BYTE $0x24;			\
  2044  	/*   RET */             BYTE $0xC3
  2045  
  2046  TEXT runtime·retpolineAX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(0)
  2047  TEXT runtime·retpolineCX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(1)
  2048  TEXT runtime·retpolineDX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(2)
  2049  TEXT runtime·retpolineBX(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(3)
  2050  /* SP is 4, can't happen / magic encodings */
  2051  TEXT runtime·retpolineBP(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(5)
  2052  TEXT runtime·retpolineSI(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(6)
  2053  TEXT runtime·retpolineDI(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(7)
  2054  TEXT runtime·retpolineR8(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(8)
  2055  TEXT runtime·retpolineR9(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(9)
  2056  TEXT runtime·retpolineR10(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(10)
  2057  TEXT runtime·retpolineR11(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(11)
  2058  TEXT runtime·retpolineR12(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(12)
  2059  TEXT runtime·retpolineR13(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(13)
  2060  TEXT runtime·retpolineR14(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(14)
  2061  TEXT runtime·retpolineR15(SB),NOSPLIT|NOFRAME,$0; RETPOLINE(15)
  2062  
  2063  TEXT ·getcallerfp<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
  2064  	MOVQ BP, AX
  2065  	RET