1// Copyright 2014 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
5package sys
6
7import (
8	"internal/goarch"
9	"internal/goos"
10)
11
12// AIX requires a larger stack for syscalls.
13// The race build also needs more stack. See issue 54291.
14// This arithmetic must match that in cmd/internal/objabi/stack.go:stackGuardMultiplier.
15const StackGuardMultiplier = 1 + goos.IsAix + isRace
16
17// DefaultPhysPageSize is the default physical page size.
18const DefaultPhysPageSize = goarch.DefaultPhysPageSize
19
20// PCQuantum is the minimal unit for a program counter (1 on x86, 4 on most other systems).
21// The various PC tables record PC deltas pre-divided by PCQuantum.
22const PCQuantum = goarch.PCQuantum
23
24// Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit).
25const Int64Align = goarch.PtrSize
26
27// MinFrameSize is the size of the system-reserved words at the bottom
28// of a frame (just above the architectural stack pointer).
29// It is zero on x86 and PtrSize on most non-x86 (LR-based) systems.
30// On PowerPC it is larger, to cover three more reserved words:
31// the compiler word, the link editor word, and the TOC save word.
32const MinFrameSize = goarch.MinFrameSize
33
34// StackAlign is the required alignment of the SP register.
35// The stack must be at least word aligned, but some architectures require more.
36const StackAlign = goarch.StackAlign
37