71 lines
2.1 KiB
ArmAsm
71 lines
2.1 KiB
ArmAsm
|
// SPDX-License-Identifier: Apache-2.0
|
||
|
|
// SPDX-FileCopyrightText: 2023 The Ebitengine Authors
|
||
|
|
|
||
|
|
//go:build darwin || freebsd || linux
|
||
|
|
|
||
|
|
#include "textflag.h"
|
||
|
|
#include "go_asm.h"
|
||
|
|
#include "funcdata.h"
|
||
|
|
#include "abi_arm64.h"
|
||
|
|
|
||
|
|
TEXT callbackasm1(SB), NOSPLIT|NOFRAME, $0
|
||
|
|
NO_LOCAL_POINTERS
|
||
|
|
|
||
|
|
// On entry, the trampoline in zcallback_darwin_arm64.s left
|
||
|
|
// the callback index in R12 (which is volatile in the C ABI).
|
||
|
|
|
||
|
|
// Save callback register arguments R0-R7 and F0-F7.
|
||
|
|
// We do this at the top of the frame so they're contiguous with stack arguments.
|
||
|
|
SUB $(16*8), RSP, R14
|
||
|
|
FSTPD (F0, F1), (0*8)(R14)
|
||
|
|
FSTPD (F2, F3), (2*8)(R14)
|
||
|
|
FSTPD (F4, F5), (4*8)(R14)
|
||
|
|
FSTPD (F6, F7), (6*8)(R14)
|
||
|
|
STP (R0, R1), (8*8)(R14)
|
||
|
|
STP (R2, R3), (10*8)(R14)
|
||
|
|
STP (R4, R5), (12*8)(R14)
|
||
|
|
STP (R6, R7), (14*8)(R14)
|
||
|
|
|
||
|
|
// Adjust SP by frame size.
|
||
|
|
SUB $(26*8), RSP
|
||
|
|
|
||
|
|
// It is important to save R27 because the go assembler
|
||
|
|
// uses it for move instructions for a variable.
|
||
|
|
// This line:
|
||
|
|
// MOVD ·callbackWrap_call(SB), R0
|
||
|
|
// Creates the instructions:
|
||
|
|
// ADRP 14335(PC), R27
|
||
|
|
// MOVD 388(27), R0
|
||
|
|
// R27 is a callee saved register so we are responsible
|
||
|
|
// for ensuring its value doesn't change. So save it and
|
||
|
|
// restore it at the end of this function.
|
||
|
|
// R30 is the link register. crosscall2 doesn't save it
|
||
|
|
// so it's saved here.
|
||
|
|
STP (R27, R30), 0(RSP)
|
||
|
|
|
||
|
|
// Create a struct callbackArgs on our stack.
|
||
|
|
MOVD $(callbackArgs__size)(RSP), R13
|
||
|
|
MOVD R12, callbackArgs_index(R13) // callback index
|
||
|
|
MOVD R14, callbackArgs_args(R13) // address of args vector
|
||
|
|
MOVD ZR, callbackArgs_result(R13) // result
|
||
|
|
|
||
|
|
// Move parameters into registers
|
||
|
|
// Get the ABIInternal function pointer
|
||
|
|
// without <ABIInternal> by using a closure.
|
||
|
|
MOVD ·callbackWrap_call(SB), R0
|
||
|
|
MOVD (R0), R0 // fn unsafe.Pointer
|
||
|
|
MOVD R13, R1 // frame (&callbackArgs{...})
|
||
|
|
MOVD $0, R3 // ctxt uintptr
|
||
|
|
|
||
|
|
BL crosscall2(SB)
|
||
|
|
|
||
|
|
// Get callback result.
|
||
|
|
MOVD $(callbackArgs__size)(RSP), R13
|
||
|
|
MOVD callbackArgs_result(R13), R0
|
||
|
|
|
||
|
|
// Restore LR and R27
|
||
|
|
LDP 0(RSP), (R27, R30)
|
||
|
|
ADD $(26*8), RSP
|
||
|
|
|
||
|
|
RET
|