asm_riscv64.s

     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.
    29  TEXT ·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.
    56  TEXT ·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
    77
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