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Diffstat (limited to 'src/runtime/tls_ppc64x.s')
| -rw-r--r-- | src/runtime/tls_ppc64x.s | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/runtime/tls_ppc64x.s b/src/runtime/tls_ppc64x.s new file mode 100644 index 0000000..c697449 --- /dev/null +++ b/src/runtime/tls_ppc64x.s @@ -0,0 +1,51 @@ +// Copyright 2014 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 ppc64 ppc64le + +#include "go_asm.h" +#include "go_tls.h" +#include "funcdata.h" +#include "textflag.h" + +// We have to resort to TLS variable to save g (R30). +// One reason is that external code might trigger +// SIGSEGV, and our runtime.sigtramp don't even know we +// are in external code, and will continue to use R30, +// this might well result in another SIGSEGV. + +// save_g saves the g register into pthread-provided +// thread-local memory, so that we can call externally compiled +// ppc64 code that will overwrite this register. +// +// If !iscgo, this is a no-op. +// +// NOTE: setg_gcc<> assume this clobbers only R31. +TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0-0 +#ifndef GOOS_aix + MOVBZ runtime·iscgo(SB), R31 + CMP R31, $0 + BEQ nocgo +#endif + MOVD runtime·tls_g(SB), R31 + MOVD g, 0(R13)(R31*1) + +nocgo: + RET + +// load_g loads the g register from pthread-provided +// thread-local memory, for use after calling externally compiled +// ppc64 code that overwrote those registers. +// +// This is never called directly from C code (it doesn't have to +// follow the C ABI), but it may be called from a C context, where the +// usual Go registers aren't set up. +// +// NOTE: _cgo_topofstack assumes this only clobbers g (R30), and R31. +TEXT runtime·load_g(SB),NOSPLIT|NOFRAME,$0-0 + MOVD runtime·tls_g(SB), R31 + MOVD 0(R13)(R31*1), g + RET + +GLOBL runtime·tls_g+0(SB), TLSBSS+DUPOK, $8 |