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 5 package sys 6 7 import ( 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. 15 const StackGuardMultiplier = 1 + goos.IsAix + isRace 16 17 // DefaultPhysPageSize is the default physical page size. 18 const 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. 22 const PCQuantum = goarch.PCQuantum 23 24 // Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit). 25 const 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. 32 const 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. 36 const StackAlign = goarch.StackAlign 37