asm_riscv64.s

Documentation: reflect

     1// Copyright 2019 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 "textflag.h"
     6#include "funcdata.h"
     7
     8// The frames of each of the two functions below contain two locals, at offsets
     9// that are known to the runtime.
    10//
    11// The first local is a bool called retValid with a whole pointer-word reserved
    12// for it on the stack. The purpose of this word is so that the runtime knows
    13// whether the stack-allocated return space contains valid values for stack
    14// scanning.
    15//
    16// The second local is an abi.RegArgs value whose offset is also known to the
    17// runtime, so that a stack map for it can be constructed, since it contains
    18// pointers visible to the GC.
    19#define LOCAL_RETVALID 40
    20#define LOCAL_REGARGS 48
    21
    22// The frame size of the functions below is
    23// 32 (args of callReflect/callMethod) + (8 bool with padding) + 392 (abi.RegArgs) = 432.
    24
    25// makeFuncStub is the code half of the function returned by MakeFunc.
    26// See the comment on the declaration of makeFuncStub in makefunc.go
    27// for more details.
    28// No arg size here, runtime pulls arg map out of the func value.
    29TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$432
    30	NO_LOCAL_POINTERS
    31	ADD	$LOCAL_REGARGS, SP, X25 // spillArgs using X25
    32	CALL	runtime·spillArgs(SB)
    33	MOV	CTXT, 32(SP) // save CTXT > args of moveMakeFuncArgPtrs < LOCAL_REGARGS
    34	MOV	CTXT, 8(SP)
    35	MOV	X25, 16(SP)
    36	CALL	·moveMakeFuncArgPtrs(SB)
    37	MOV	32(SP), CTXT // restore CTXT
    38
    39	MOV	CTXT, 8(SP)
    40	MOV	$argframe+0(FP), T0
    41	MOV	T0, 16(SP)
    42	MOV	ZERO, LOCAL_RETVALID(SP)
    43	ADD	$LOCAL_RETVALID, SP, T1
    44	MOV	T1, 24(SP)
    45	ADD	$LOCAL_REGARGS, SP, T1
    46	MOV	T1, 32(SP)
    47	CALL	·callReflect(SB)
    48	ADD	$LOCAL_REGARGS, SP, X25 // unspillArgs using X25
    49	CALL	runtime·unspillArgs(SB)
    50	RET
    51
    52// methodValueCall is the code half of the function returned by makeMethodValue.
    53// See the comment on the declaration of methodValueCall in makefunc.go
    54// for more details.
    55// No arg size here; runtime pulls arg map out of the func value.
    56TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$432
    57	NO_LOCAL_POINTERS
    58	ADD	$LOCAL_REGARGS, SP, X25 // spillArgs using X25
    59	CALL	runtime·spillArgs(SB)
    60	MOV	CTXT, 32(SP) // save CTXT
    61	MOV	CTXT, 8(SP)
    62	MOV	X25, 16(SP)
    63	CALL	·moveMakeFuncArgPtrs(SB)
    64	MOV	32(SP), CTXT // restore CTXT
    65	MOV	CTXT, 8(SP)
    66	MOV	$argframe+0(FP), T0
    67	MOV	T0, 16(SP)
    68	MOV	ZERO, LOCAL_RETVALID(SP)
    69	ADD	$LOCAL_RETVALID, SP, T1
    70	MOV	T1, 24(SP)
    71	ADD	$LOCAL_REGARGS, SP, T1
    72	MOV	T1, 32(SP) // frame size to 32+SP as callreflect args
    73	CALL	·callMethod(SB)
    74	ADD	$LOCAL_REGARGS, SP, X25 // unspillArgs using X25
    75	CALL	runtime·unspillArgs(SB)
    76	RET
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