github.com/lovishpuri/go-40569/src@v0.0.0-20230519171745-f8623e7c56cf/runtime/cgo/asm_arm.s (about) 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 7 // Set the x_crosscall2_ptr C function pointer variable point to crosscall2. 8 // It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2 9 TEXT ·set_crosscall2(SB),NOSPLIT,$0-0 10 MOVW _crosscall2_ptr(SB), R1 11 MOVW $crosscall2(SB), R2 12 MOVW R2, (R1) 13 RET 14 15 // Called by C code generated by cmd/cgo. 16 // func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr) 17 // Saves C callee-saved registers and calls cgocallback with three arguments. 18 // fn is the PC of a func(a unsafe.Pointer) function. 19 TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0 20 SUB $(8*9), R13 // Reserve space for the floating point registers. 21 // The C arguments arrive in R0, R1, R2, and R3. We want to 22 // pass R0, R1, and R3 to Go, so we push those on the stack. 23 // Also, save C callee-save registers R4-R12. 24 MOVM.WP [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12], (R13) 25 // Finally, save the link register R14. This also puts the 26 // arguments we pushed for cgocallback where they need to be, 27 // starting at 4(R13). 28 MOVW.W R14, -4(R13) 29 30 // Skip floating point registers on GOARM < 6. 31 MOVB runtime·goarm(SB), R11 32 CMP $6, R11 33 BLT skipfpsave 34 MOVD F8, (13*4+8*1)(R13) 35 MOVD F9, (13*4+8*2)(R13) 36 MOVD F10, (13*4+8*3)(R13) 37 MOVD F11, (13*4+8*4)(R13) 38 MOVD F12, (13*4+8*5)(R13) 39 MOVD F13, (13*4+8*6)(R13) 40 MOVD F14, (13*4+8*7)(R13) 41 MOVD F15, (13*4+8*8)(R13) 42 43 skipfpsave: 44 BL runtime·load_g(SB) 45 // We set up the arguments to cgocallback when saving registers above. 46 BL runtime·cgocallback(SB) 47 48 MOVB runtime·goarm(SB), R11 49 CMP $6, R11 50 BLT skipfprest 51 MOVD (13*4+8*1)(R13), F8 52 MOVD (13*4+8*2)(R13), F9 53 MOVD (13*4+8*3)(R13), F10 54 MOVD (13*4+8*4)(R13), F11 55 MOVD (13*4+8*5)(R13), F12 56 MOVD (13*4+8*6)(R13), F13 57 MOVD (13*4+8*7)(R13), F14 58 MOVD (13*4+8*8)(R13), F15 59 60 skipfprest: 61 MOVW.P 4(R13), R14 62 MOVM.IAW (R13), [R0, R1, R3, R4, R5, R6, R7, R8, R9, g, R11, R12] 63 ADD $(8*9), R13 64 MOVW R14, R15