asm_amd64.s

Documentation: reflect

     1  // Copyright 2012 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  #include "go_asm.h"
     8  
     9  // The frames of each of the two functions below contain two locals, at offsets
    10  // that are known to the runtime.
    11  //
    12  // The first local is a bool called retValid with a whole pointer-word reserved
    13  // for it on the stack. The purpose of this word is so that the runtime knows
    14  // whether the stack-allocated return space contains valid values for stack
    15  // scanning.
    16  //
    17  // The second local is an abi.RegArgs value whose offset is also known to the
    18  // runtime, so that a stack map for it can be constructed, since it contains
    19  // pointers visible to the GC.
    20  #define LOCAL_RETVALID 32
    21  #define LOCAL_REGARGS 40
    22  
    23  // makeFuncStub is the code half of the function returned by MakeFunc.
    24  // See the comment on the declaration of makeFuncStub in makefunc.go
    25  // for more details.
    26  // No arg size here; runtime pulls arg map out of the func value.
    27  // makeFuncStub must be ABIInternal because it is placed directly
    28  // in function values.
    29  // This frame contains two locals. See the comment above LOCAL_RETVALID.
    30  TEXT ·makeFuncStub<ABIInternal>(SB),(NOSPLIT|WRAPPER),$312
    31  	NO_LOCAL_POINTERS
    32  	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
    33  	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
    34  	LEAQ	LOCAL_REGARGS(SP), R12
    35  	CALL	runtime·spillArgs<ABIInternal>(SB)
    36  	MOVQ	DX, 24(SP) // outside of moveMakeFuncArgPtrs's arg area
    37  	MOVQ	DX, 0(SP)
    38  	MOVQ	R12, 8(SP)
    39  	CALL	·moveMakeFuncArgPtrs(SB)
    40  	MOVQ	24(SP), DX
    41  	MOVQ	DX, 0(SP)
    42  	LEAQ	argframe+0(FP), CX
    43  	MOVQ	CX, 8(SP)
    44  	MOVB	$0, LOCAL_RETVALID(SP)
    45  	LEAQ	LOCAL_RETVALID(SP), AX
    46  	MOVQ	AX, 16(SP)
    47  	LEAQ	LOCAL_REGARGS(SP), AX
    48  	MOVQ	AX, 24(SP)
    49  	CALL	·callReflect(SB)
    50  	LEAQ	LOCAL_REGARGS(SP), R12
    51  	CALL	runtime·unspillArgs<ABIInternal>(SB)
    52  	RET
    53  
    54  // methodValueCall is the code half of the function returned by makeMethodValue.
    55  // See the comment on the declaration of methodValueCall in makefunc.go
    56  // for more details.
    57  // No arg size here; runtime pulls arg map out of the func value.
    58  // methodValueCall must be ABIInternal because it is placed directly
    59  // in function values.
    60  // This frame contains two locals. See the comment above LOCAL_RETVALID.
    61  TEXT ·methodValueCall<ABIInternal>(SB),(NOSPLIT|WRAPPER),$312
    62  	NO_LOCAL_POINTERS
    63  	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
    64  	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
    65  	LEAQ	LOCAL_REGARGS(SP), R12
    66  	CALL	runtime·spillArgs<ABIInternal>(SB)
    67  	MOVQ	DX, 24(SP) // outside of moveMakeFuncArgPtrs's arg area
    68  	MOVQ	DX, 0(SP)
    69  	MOVQ	R12, 8(SP)
    70  	CALL	·moveMakeFuncArgPtrs(SB)
    71  	MOVQ	24(SP), DX
    72  	MOVQ	DX, 0(SP)
    73  	LEAQ	argframe+0(FP), CX
    74  	MOVQ	CX, 8(SP)
    75  	MOVB	$0, LOCAL_RETVALID(SP)
    76  	LEAQ	LOCAL_RETVALID(SP), AX
    77  	MOVQ	AX, 16(SP)
    78  	LEAQ	LOCAL_REGARGS(SP), AX
    79  	MOVQ	AX, 24(SP)
    80  	CALL	·callMethod(SB)
    81  	LEAQ	LOCAL_REGARGS(SP), R12
    82  	CALL	runtime·unspillArgs<ABIInternal>(SB)
    83  	RET
    84
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