blob: 198c59a33e7a0c61e8f48e5c3c2dd783b41d847a [file] [log] [blame]
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build mips || mipsle
#include "textflag.h"
// Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
// Use a local trampoline, to avoid taking the address of a dynamically exported
// function.
TEXT ·set_crosscall2(SB),NOSPLIT,$0-0
MOVW _crosscall2_ptr(SB), R5
MOVW $crosscall2_trampoline<>(SB), R6
MOVW R6, (R5)
RET
TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0
JMP crosscall2(SB)
// Called by C code generated by cmd/cgo.
// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
// Saves C callee-saved registers and calls cgocallback with three arguments.
// fn is the PC of a func(a unsafe.Pointer) function.
TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
/*
* We still need to save all callee save register as before, and then
* push 3 args for fn (R4, R5, R7), skipping R6.
* Also note that at procedure entry in gc world, 4(R29) will be the
* first arg.
*/
// Space for 9 caller-saved GPR + LR + 6 caller-saved FPR.
// O32 ABI allows us to smash 16 bytes argument area of caller frame.
#ifndef GOMIPS_softfloat
SUBU $(4*14+8*6-16), R29
#else
SUBU $(4*14-16), R29 // For soft-float, no FPR.
#endif
MOVW R4, (4*1)(R29) // fn unsafe.Pointer
MOVW R5, (4*2)(R29) // a unsafe.Pointer
MOVW R7, (4*3)(R29) // ctxt uintptr
MOVW R16, (4*4)(R29)
MOVW R17, (4*5)(R29)
MOVW R18, (4*6)(R29)
MOVW R19, (4*7)(R29)
MOVW R20, (4*8)(R29)
MOVW R21, (4*9)(R29)
MOVW R22, (4*10)(R29)
MOVW R23, (4*11)(R29)
MOVW g, (4*12)(R29)
MOVW R31, (4*13)(R29)
#ifndef GOMIPS_softfloat
MOVD F20, (4*14)(R29)
MOVD F22, (4*14+8*1)(R29)
MOVD F24, (4*14+8*2)(R29)
MOVD F26, (4*14+8*3)(R29)
MOVD F28, (4*14+8*4)(R29)
MOVD F30, (4*14+8*5)(R29)
#endif
JAL runtime·load_g(SB)
JAL runtime·cgocallback(SB)
MOVW (4*4)(R29), R16
MOVW (4*5)(R29), R17
MOVW (4*6)(R29), R18
MOVW (4*7)(R29), R19
MOVW (4*8)(R29), R20
MOVW (4*9)(R29), R21
MOVW (4*10)(R29), R22
MOVW (4*11)(R29), R23
MOVW (4*12)(R29), g
MOVW (4*13)(R29), R31
#ifndef GOMIPS_softfloat
MOVD (4*14)(R29), F20
MOVD (4*14+8*1)(R29), F22
MOVD (4*14+8*2)(R29), F24
MOVD (4*14+8*3)(R29), F26
MOVD (4*14+8*4)(R29), F28
MOVD (4*14+8*5)(R29), F30
ADDU $(4*14+8*6-16), R29
#else
ADDU $(4*14-16), R29
#endif
RET