asm_ppc64x.h

Documentation: runtime

		 1// Copyright 2015 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// FIXED_FRAME defines the size of the fixed part of a stack frame. A stack
		 6// frame looks like this:
		 7//
		 8// +---------------------+
		 9// | local variable area |
		10// +---------------------+
		11// | argument area			 |
		12// +---------------------+ <- R1+FIXED_FRAME
		13// | fixed area					|
		14// +---------------------+ <- R1
		15//
		16// So a function that sets up a stack frame at all uses as least FIXED_FRAME
		17// bytes of stack. This mostly affects assembly that calls other functions
		18// with arguments (the arguments should be stored at FIXED_FRAME+0(R1),
		19// FIXED_FRAME+8(R1) etc) and some other low-level places.
		20//
		21// The reason for using a constant is to make supporting PIC easier (although
		22// we only support PIC on ppc64le which has a minimum 32 bytes of stack frame,
		23// and currently always use that much, PIC on ppc64 would need to use 48).
		24
		25#define FIXED_FRAME 32
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