asm_amd64.s

     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  // This frame contains two locals. See the comment above LOCAL_RETVALID.
    28  TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$312
    29  	NO_LOCAL_POINTERS
    30  	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
    31  	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
    32  	LEAQ	LOCAL_REGARGS(SP), R12
    33  	CALL	runtime·spillArgs(SB)
    34  	MOVQ	DX, 24(SP) // outside of moveMakeFuncArgPtrs's arg area
    35  	MOVQ	DX, 0(SP)
    36  	MOVQ	R12, 8(SP)
    37  	CALL	·moveMakeFuncArgPtrs(SB)
    38  	MOVQ	24(SP), DX
    39  	MOVQ	DX, 0(SP)
    40  	LEAQ	argframe+0(FP), CX
    41  	MOVQ	CX, 8(SP)
    42  	MOVB	$0, LOCAL_RETVALID(SP)
    43  	LEAQ	LOCAL_RETVALID(SP), AX
    44  	MOVQ	AX, 16(SP)
    45  	LEAQ	LOCAL_REGARGS(SP), AX
    46  	MOVQ	AX, 24(SP)
    47  	CALL	·callReflect(SB)
    48  	LEAQ	LOCAL_REGARGS(SP), R12
    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  // This frame contains two locals. See the comment above LOCAL_RETVALID.
    57  TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$312
    58  	NO_LOCAL_POINTERS
    59  	// NO_LOCAL_POINTERS is a lie. The stack map for the two locals in this
    60  	// frame is specially handled in the runtime. See the comment above LOCAL_RETVALID.
    61  	LEAQ	LOCAL_REGARGS(SP), R12
    62  	CALL	runtime·spillArgs(SB)
    63  	MOVQ	DX, 24(SP) // outside of moveMakeFuncArgPtrs's arg area
    64  	MOVQ	DX, 0(SP)
    65  	MOVQ	R12, 8(SP)
    66  	CALL	·moveMakeFuncArgPtrs(SB)
    67  	MOVQ	24(SP), DX
    68  	MOVQ	DX, 0(SP)
    69  	LEAQ	argframe+0(FP), CX
    70  	MOVQ	CX, 8(SP)
    71  	MOVB	$0, LOCAL_RETVALID(SP)
    72  	LEAQ	LOCAL_RETVALID(SP), AX
    73  	MOVQ	AX, 16(SP)
    74  	LEAQ	LOCAL_REGARGS(SP), AX
    75  	MOVQ	AX, 24(SP)
    76  	CALL	·callMethod(SB)
    77  	LEAQ	LOCAL_REGARGS(SP), R12
    78  	CALL	runtime·unspillArgs(SB)
    79  	RET
    80
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