libgo: Update to revision 15193:6fdc1974457c of master library.

From-SVN: r194692

1 files changed, 42 insertions, 0 deletions

diff --git a/libgo/runtime/mgc0.h b/libgo/runtime/mgc0.h
new file mode 100644
index 0000000..a2798ef
--- /dev/null
+++ b/libgo/runtime/mgc0.h
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+// Copyright 2012 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.
+
+// Garbage collector (GC)
+
+// GC instruction opcodes.
+//
+// The opcode of an instruction is followed by zero or more
+// arguments to the instruction.
+//
+// Meaning of arguments:
+//   off      Offset (in bytes) from the start of the current object
+//   objgc    Pointer to GC info of an object
+//   len      Length of an array
+//   elemsize Size (in bytes) of an element
+//   size     Size (in bytes)
+enum {
+	GC_END,         // End of object, loop or subroutine. Args: none
+	GC_PTR,         // A typed pointer. Args: (off, objgc)
+	GC_APTR,        // Pointer to an arbitrary object. Args: (off)
+	GC_ARRAY_START, // Start an array with a fixed length. Args: (off, len, elemsize)
+	GC_ARRAY_NEXT,  // The next element of an array. Args: none
+	GC_CALL,        // Call a subroutine. Args: (off, objgc)
+	GC_MAP_PTR,     // Go map. Args: (off, MapType*)
+	GC_STRING,      // Go string. Args: (off)
+	GC_EFACE,       // interface{}. Args: (off)
+	GC_IFACE,       // interface{...}. Args: (off)
+	GC_SLICE,       // Go slice. Args: (off, objgc)
+	GC_REGION,      // A region/part of the current object. Args: (off, size, objgc)
+
+	GC_NUM_INSTR,   // Number of instruction opcodes
+};
+
+enum {
+	// Size of GC's fixed stack.
+	//
+	// The current GC implementation permits:
+	//  - at most 1 stack allocation because of GC_CALL
+	//  - at most GC_STACK_CAPACITY allocations because of GC_ARRAY_START
+	GC_STACK_CAPACITY = 8,	
+};