| // Copyright 2015 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. |
| |
| // +build mips64 mips64le |
| |
| package runtime |
| |
| import "unsafe" |
| |
| // adjust Gobuf as if it executed a call to fn with context ctxt |
| // and then did an immediate Gosave. |
| func gostartcall(buf *gobuf, fn, ctxt unsafe.Pointer) { |
| if buf.lr != 0 { |
| throw("invalid use of gostartcall") |
| } |
| buf.lr = buf.pc |
| buf.pc = uintptr(fn) |
| buf.ctxt = ctxt |
| } |
| |
| // Called to rewind context saved during morestack back to beginning of function. |
| // To help us, the linker emits a jmp back to the beginning right after the |
| // call to morestack. We just have to decode and apply that jump. |
| func rewindmorestack(buf *gobuf) { |
| var inst uint32 |
| if buf.pc&3 == 0 && buf.pc != 0 { |
| inst = *(*uint32)(unsafe.Pointer(buf.pc)) |
| if inst>>26 == 2 { // JMP addr |
| //print("runtime: rewind pc=", hex(buf.pc), " to pc=", hex(buf.pc &^ uintptr(1<<28-1) | uintptr((inst&^0xfc000000)<<2)), "\n"); |
| buf.pc &^= 1<<28 - 1 |
| buf.pc |= uintptr((inst &^ 0xfc000000) << 2) |
| return |
| } |
| if inst>>16 == 0x1000 { // BEQ R0, R0, offset |
| //print("runtime: rewind pc=", hex(buf.pc), " to pc=", hex(buf.pc + uintptr(int32(int16(inst&0xffff))<<2 + 4)), "\n"); |
| buf.pc += uintptr(int32(int16(inst&0xffff))<<2 + 4) |
| return |
| } |
| } |
| print("runtime: pc=", hex(buf.pc), " ", hex(inst), "\n") |
| throw("runtime: misuse of rewindmorestack") |
| } |
