runtime,internal: move runtime/internal/sys to internal/runtime/sys

Cleanup and friction reduction

For #65355.

Change-Id: Ia14c9dc584a529a35b97801dd3e95b9acc99a511
Reviewed-on: https://go-review.googlesource.com/c/go/+/600436
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>

7 files changed, 0 insertions, 352 deletions

diff --git a/src/runtime/internal/sys/consts.go b/src/runtime/internal/sys/consts.go
deleted file mode 100644
index 98c0f09ef1..0000000000
--- a/src/runtime/internal/sys/consts.go
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2014 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.
-
-package sys
-
-import (
-	"internal/goarch"
-	"internal/goos"
-)
-
-// AIX requires a larger stack for syscalls.
-// The race build also needs more stack. See issue 54291.
-// This arithmetic must match that in cmd/internal/objabi/stack.go:stackGuardMultiplier.
-const StackGuardMultiplier = 1 + goos.IsAix + isRace
-
-// DefaultPhysPageSize is the default physical page size.
-const DefaultPhysPageSize = goarch.DefaultPhysPageSize
-
-// PCQuantum is the minimal unit for a program counter (1 on x86, 4 on most other systems).
-// The various PC tables record PC deltas pre-divided by PCQuantum.
-const PCQuantum = goarch.PCQuantum
-
-// Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit).
-const Int64Align = goarch.PtrSize
-
-// MinFrameSize is the size of the system-reserved words at the bottom
-// of a frame (just above the architectural stack pointer).
-// It is zero on x86 and PtrSize on most non-x86 (LR-based) systems.
-// On PowerPC it is larger, to cover three more reserved words:
-// the compiler word, the link editor word, and the TOC save word.
-const MinFrameSize = goarch.MinFrameSize
-
-// StackAlign is the required alignment of the SP register.
-// The stack must be at least word aligned, but some architectures require more.
-const StackAlign = goarch.StackAlign
diff --git a/src/runtime/internal/sys/consts_norace.go b/src/runtime/internal/sys/consts_norace.go
deleted file mode 100644
index a9613b8843..0000000000
--- a/src/runtime/internal/sys/consts_norace.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2022 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.
-
-//go:build !race
-
-package sys
-
-const isRace = 0
diff --git a/src/runtime/internal/sys/consts_race.go b/src/runtime/internal/sys/consts_race.go
deleted file mode 100644
index f824fb39d3..0000000000
--- a/src/runtime/internal/sys/consts_race.go
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright 2022 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.
-
-//go:build race
-
-package sys
-
-const isRace = 1
diff --git a/src/runtime/internal/sys/intrinsics.go b/src/runtime/internal/sys/intrinsics.go
deleted file mode 100644
index e6a3758447..0000000000
--- a/src/runtime/internal/sys/intrinsics.go
+++ /dev/null
@@ -1,208 +0,0 @@
-// Copyright 2016 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.
-
-package sys
-
-// Copied from math/bits to avoid dependence.
-
-var deBruijn32tab = [32]byte{
-	0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
-	31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9,
-}
-
-const deBruijn32 = 0x077CB531
-
-var deBruijn64tab = [64]byte{
-	0, 1, 56, 2, 57, 49, 28, 3, 61, 58, 42, 50, 38, 29, 17, 4,
-	62, 47, 59, 36, 45, 43, 51, 22, 53, 39, 33, 30, 24, 18, 12, 5,
-	63, 55, 48, 27, 60, 41, 37, 16, 46, 35, 44, 21, 52, 32, 23, 11,
-	54, 26, 40, 15, 34, 20, 31, 10, 25, 14, 19, 9, 13, 8, 7, 6,
-}
-
-const deBruijn64 = 0x03f79d71b4ca8b09
-
-const ntz8tab = "" +
-	"\x08\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x05\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x06\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x05\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x07\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x05\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x06\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x05\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00" +
-	"\x04\x00\x01\x00\x02\x00\x01\x00\x03\x00\x01\x00\x02\x00\x01\x00"
-
-// TrailingZeros32 returns the number of trailing zero bits in x; the result is 32 for x == 0.
-func TrailingZeros32(x uint32) int {
-	if x == 0 {
-		return 32
-	}
-	// see comment in TrailingZeros64
-	return int(deBruijn32tab[(x&-x)*deBruijn32>>(32-5)])
-}
-
-// TrailingZeros64 returns the number of trailing zero bits in x; the result is 64 for x == 0.
-func TrailingZeros64(x uint64) int {
-	if x == 0 {
-		return 64
-	}
-	// If popcount is fast, replace code below with return popcount(^x & (x - 1)).
-	//
-	// x & -x leaves only the right-most bit set in the word. Let k be the
-	// index of that bit. Since only a single bit is set, the value is two
-	// to the power of k. Multiplying by a power of two is equivalent to
-	// left shifting, in this case by k bits. The de Bruijn (64 bit) constant
-	// is such that all six bit, consecutive substrings are distinct.
-	// Therefore, if we have a left shifted version of this constant we can
-	// find by how many bits it was shifted by looking at which six bit
-	// substring ended up at the top of the word.
-	// (Knuth, volume 4, section 7.3.1)
-	return int(deBruijn64tab[(x&-x)*deBruijn64>>(64-6)])
-}
-
-// TrailingZeros8 returns the number of trailing zero bits in x; the result is 8 for x == 0.
-func TrailingZeros8(x uint8) int {
-	return int(ntz8tab[x])
-}
-
-const len8tab = "" +
-	"\x00\x01\x02\x02\x03\x03\x03\x03\x04\x04\x04\x04\x04\x04\x04\x04" +
-	"\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05\x05" +
-	"\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06" +
-	"\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06\x06" +
-	"\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07" +
-	"\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07" +
-	"\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07" +
-	"\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07\x07" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08" +
-	"\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08"
-
-// Len64 returns the minimum number of bits required to represent x; the result is 0 for x == 0.
-//
-// nosplit because this is used in src/runtime/histogram.go, which make run in sensitive contexts.
-//
-//go:nosplit
-func Len64(x uint64) (n int) {
-	if x >= 1<<32 {
-		x >>= 32
-		n = 32
-	}
-	if x >= 1<<16 {
-		x >>= 16
-		n += 16
-	}
-	if x >= 1<<8 {
-		x >>= 8
-		n += 8
-	}
-	return n + int(len8tab[x])
-}
-
-// --- OnesCount ---
-
-const m0 = 0x5555555555555555 // 01010101 ...
-const m1 = 0x3333333333333333 // 00110011 ...
-const m2 = 0x0f0f0f0f0f0f0f0f // 00001111 ...
-
-// OnesCount64 returns the number of one bits ("population count") in x.
-func OnesCount64(x uint64) int {
-	// Implementation: Parallel summing of adjacent bits.
-	// See "Hacker's Delight", Chap. 5: Counting Bits.
-	// The following pattern shows the general approach:
-	//
-	//   x = x>>1&(m0&m) + x&(m0&m)
-	//   x = x>>2&(m1&m) + x&(m1&m)
-	//   x = x>>4&(m2&m) + x&(m2&m)
-	//   x = x>>8&(m3&m) + x&(m3&m)
-	//   x = x>>16&(m4&m) + x&(m4&m)
-	//   x = x>>32&(m5&m) + x&(m5&m)
-	//   return int(x)
-	//
-	// Masking (& operations) can be left away when there's no
-	// danger that a field's sum will carry over into the next
-	// field: Since the result cannot be > 64, 8 bits is enough
-	// and we can ignore the masks for the shifts by 8 and up.
-	// Per "Hacker's Delight", the first line can be simplified
-	// more, but it saves at best one instruction, so we leave
-	// it alone for clarity.
-	const m = 1<<64 - 1
-	x = x>>1&(m0&m) + x&(m0&m)
-	x = x>>2&(m1&m) + x&(m1&m)
-	x = (x>>4 + x) & (m2 & m)
-	x += x >> 8
-	x += x >> 16
-	x += x >> 32
-	return int(x) & (1<<7 - 1)
-}
-
-// LeadingZeros64 returns the number of leading zero bits in x; the result is 64 for x == 0.
-func LeadingZeros64(x uint64) int { return 64 - Len64(x) }
-
-// LeadingZeros8 returns the number of leading zero bits in x; the result is 8 for x == 0.
-func LeadingZeros8(x uint8) int { return 8 - Len8(x) }
-
-// Len8 returns the minimum number of bits required to represent x; the result is 0 for x == 0.
-func Len8(x uint8) int {
-	return int(len8tab[x])
-}
-
-// Bswap64 returns its input with byte order reversed
-// 0x0102030405060708 -> 0x0807060504030201
-func Bswap64(x uint64) uint64 {
-	c8 := uint64(0x00ff00ff00ff00ff)
-	a := x >> 8 & c8
-	b := (x & c8) << 8
-	x = a | b
-	c16 := uint64(0x0000ffff0000ffff)
-	a = x >> 16 & c16
-	b = (x & c16) << 16
-	x = a | b
-	c32 := uint64(0x00000000ffffffff)
-	a = x >> 32 & c32
-	b = (x & c32) << 32
-	x = a | b
-	return x
-}
-
-// Bswap32 returns its input with byte order reversed
-// 0x01020304 -> 0x04030201
-func Bswap32(x uint32) uint32 {
-	c8 := uint32(0x00ff00ff)
-	a := x >> 8 & c8
-	b := (x & c8) << 8
-	x = a | b
-	c16 := uint32(0x0000ffff)
-	a = x >> 16 & c16
-	b = (x & c16) << 16
-	x = a | b
-	return x
-}
-
-// Prefetch prefetches data from memory addr to cache
-//
-// AMD64: Produce PREFETCHT0 instruction
-//
-// ARM64: Produce PRFM instruction with PLDL1KEEP option
-func Prefetch(addr uintptr) {}
-
-// PrefetchStreamed prefetches data from memory addr, with a hint that this data is being streamed.
-// That is, it is likely to be accessed very soon, but only once. If possible, this will avoid polluting the cache.
-//
-// AMD64: Produce PREFETCHNTA instruction
-//
-// ARM64: Produce PRFM instruction with PLDL1STRM option
-func PrefetchStreamed(addr uintptr) {}
diff --git a/src/runtime/internal/sys/intrinsics_test.go b/src/runtime/internal/sys/intrinsics_test.go
deleted file mode 100644
index 6799885001..0000000000
--- a/src/runtime/internal/sys/intrinsics_test.go
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright 2016 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.
-
-package sys_test
-
-import (
-	"runtime/internal/sys"
-	"testing"
-)
-
-func TestTrailingZeros64(t *testing.T) {
-	for i := 0; i <= 64; i++ {
-		x := uint64(5) << uint(i)
-		if got := sys.TrailingZeros64(x); got != i {
-			t.Errorf("TrailingZeros64(%d)=%d, want %d", x, got, i)
-		}
-	}
-}
-func TestTrailingZeros32(t *testing.T) {
-	for i := 0; i <= 32; i++ {
-		x := uint32(5) << uint(i)
-		if got := sys.TrailingZeros32(x); got != i {
-			t.Errorf("TrailingZeros32(%d)=%d, want %d", x, got, i)
-		}
-	}
-}
-
-func TestBswap64(t *testing.T) {
-	x := uint64(0x1122334455667788)
-	y := sys.Bswap64(x)
-	if y != 0x8877665544332211 {
-		t.Errorf("Bswap(%x)=%x, want 0x8877665544332211", x, y)
-	}
-}
-func TestBswap32(t *testing.T) {
-	x := uint32(0x11223344)
-	y := sys.Bswap32(x)
-	if y != 0x44332211 {
-		t.Errorf("Bswap(%x)=%x, want 0x44332211", x, y)
-	}
-}
diff --git a/src/runtime/internal/sys/nih.go b/src/runtime/internal/sys/nih.go
deleted file mode 100644
index 17eab67345..0000000000
--- a/src/runtime/internal/sys/nih.go
+++ /dev/null
@@ -1,41 +0,0 @@
-// Copyright 2014 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.
-
-package sys
-
-// NOTE: keep in sync with cmd/compile/internal/types.CalcSize
-// to make the compiler recognize this as an intrinsic type.
-type nih struct{}
-
-// NotInHeap is a type must never be allocated from the GC'd heap or on the stack,
-// and is called not-in-heap.
-//
-// Other types can embed NotInHeap to make it not-in-heap. Specifically, pointers
-// to these types must always fail the `runtime.inheap` check. The type may be used
-// for global variables, or for objects in unmanaged memory (e.g., allocated with
-// `sysAlloc`, `persistentalloc`, r`fixalloc`, or from a manually-managed span).
-//
-// Specifically:
-//
-// 1. `new(T)`, `make([]T)`, `append([]T, ...)` and implicit heap
-// allocation of T are disallowed. (Though implicit allocations are
-// disallowed in the runtime anyway.)
-//
-// 2. A pointer to a regular type (other than `unsafe.Pointer`) cannot be
-// converted to a pointer to a not-in-heap type, even if they have the
-// same underlying type.
-//
-// 3. Any type that containing a not-in-heap type is itself considered as not-in-heap.
-//
-// - Structs and arrays are not-in-heap if their elements are not-in-heap.
-// - Maps and channels contains no-in-heap types are disallowed.
-//
-// 4. Write barriers on pointers to not-in-heap types can be omitted.
-//
-// The last point is the real benefit of NotInHeap. The runtime uses
-// it for low-level internal structures to avoid memory barriers in the
-// scheduler and the memory allocator where they are illegal or simply
-// inefficient. This mechanism is reasonably safe and does not compromise
-// the readability of the runtime.
-type NotInHeap struct{ _ nih }
diff --git a/src/runtime/internal/sys/sys.go b/src/runtime/internal/sys/sys.go
deleted file mode 100644
index 694101d36f..0000000000
--- a/src/runtime/internal/sys/sys.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// Copyright 2015 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.
-
-// package sys contains system- and configuration- and architecture-specific
-// constants used by the runtime.
-package sys