1 // Copyright 2021 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 goarch contains GOARCH-specific constants.
6 package goarch
7 8 // The next line makes 'go generate' write the zgoarch*.go files with
9 // per-arch information, including constants named $GOARCH for every
10 // GOARCH. The constant is 1 on the current system, 0 otherwise; multiplying
11 // by them is useful for defining GOARCH-specific constants.
12 //
13 //go:generate go run gengoarch.go
14 15 // ArchFamilyType represents a family of one or more related architectures.
16 // For example, ppc64 and ppc64le are both members of the PPC64 family.
17 type ArchFamilyType int
18 19 const (
20 AMD64 ArchFamilyType = iota
21 ARM
22 ARM64
23 I386
24 LOONG64
25 MIPS
26 MIPS64
27 PPC64
28 RISCV64
29 S390X
30 WASM
31 )
32 33 // PtrSize is the size of a pointer in bytes - unsafe.Sizeof(uintptr(0)) but as an ideal constant.
34 // It is also the size of the machine's native word size (that is, 4 on 32-bit systems, 8 on 64-bit).
35 const PtrSize = 4 << (^uintptr(0) >> 63)
36 37 // ArchFamily is the architecture family (AMD64, ARM, ...)
38 const ArchFamily ArchFamilyType = _ArchFamily
39 40 // BigEndian reports whether the architecture is big-endian.
41 const BigEndian = IsArmbe|IsArm64be|IsMips|IsMips64|IsPpc|IsPpc64|IsS390|IsS390x|IsSparc|IsSparc64 == 1
42 43 // DefaultPhysPageSize is the default physical page size.
44 const DefaultPhysPageSize = _DefaultPhysPageSize
45 46 // PCQuantum is the minimal unit for a program counter (1 on x86, 4 on most other systems).
47 // The various PC tables record PC deltas pre-divided by PCQuantum.
48 const PCQuantum = _PCQuantum
49 50 // Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit).
51 const Int64Align = PtrSize
52 53 // MinFrameSize is the size of the system-reserved words at the bottom
54 // of a frame (just above the architectural stack pointer).
55 // It is zero on x86 and PtrSize on most non-x86 (LR-based) systems.
56 // On PowerPC it is larger, to cover three more reserved words:
57 // the compiler word, the link editor word, and the TOC save word.
58 const MinFrameSize = _MinFrameSize
59 60 // StackAlign is the required alignment of the SP register.
61 // The stack must be at least word aligned, but some architectures require more.
62 const StackAlign = _StackAlign
63