Initial QSfera import

Server/vendor/github.com/klauspost/crc32/crc32_ppc64le.go

@@ -0,0 +1,88 @@
+// Copyright 2017 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 crc32
+
+import (
+	"unsafe"
+)
+
+const (
+	vecMinLen    = 16
+	vecAlignMask = 15 // align to 16 bytes
+	crcIEEE      = 1
+	crcCast      = 2
+)
+
+//go:noescape
+func ppc64SlicingUpdateBy8(crc uint32, table8 *slicing8Table, p []byte) uint32
+
+// this function requires the buffer to be 16 byte aligned and > 16 bytes long.
+//
+//go:noescape
+func vectorCrc32(crc uint32, poly uint32, p []byte) uint32
+
+var archCastagnoliTable8 *slicing8Table
+
+func archInitCastagnoli() {
+	archCastagnoliTable8 = slicingMakeTable(Castagnoli)
+}
+
+func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
+	if len(p) >= 4*vecMinLen {
+		// If not aligned then process the initial unaligned bytes
+
+		if uint64(uintptr(unsafe.Pointer(&p[0])))&uint64(vecAlignMask) != 0 {
+			align := uint64(uintptr(unsafe.Pointer(&p[0]))) & uint64(vecAlignMask)
+			newlen := vecMinLen - align
+			crc = ppc64SlicingUpdateBy8(crc, archCastagnoliTable8, p[:newlen])
+			p = p[newlen:]
+		}
+		// p should be aligned now
+		aligned := len(p) & ^vecAlignMask
+		crc = vectorCrc32(crc, crcCast, p[:aligned])
+		p = p[aligned:]
+	}
+	if len(p) == 0 {
+		return crc
+	}
+	return ppc64SlicingUpdateBy8(crc, archCastagnoliTable8, p)
+}
+
+func archAvailableIEEE() bool {
+	return true
+}
+func archAvailableCastagnoli() bool {
+	return true
+}
+
+var archIeeeTable8 *slicing8Table
+
+func archInitIEEE() {
+	// We still use slicing-by-8 for small buffers.
+	archIeeeTable8 = slicingMakeTable(IEEE)
+}
+
+// archUpdateIEEE calculates the checksum of p using vectorizedIEEE.
+func archUpdateIEEE(crc uint32, p []byte) uint32 {
+
+	// Check if vector code should be used.  If not aligned, then handle those
+	// first up to the aligned bytes.
+
+	if len(p) >= 4*vecMinLen {
+		if uint64(uintptr(unsafe.Pointer(&p[0])))&uint64(vecAlignMask) != 0 {
+			align := uint64(uintptr(unsafe.Pointer(&p[0]))) & uint64(vecAlignMask)
+			newlen := vecMinLen - align
+			crc = ppc64SlicingUpdateBy8(crc, archIeeeTable8, p[:newlen])
+			p = p[newlen:]
+		}
+		aligned := len(p) & ^vecAlignMask
+		crc = vectorCrc32(crc, crcIEEE, p[:aligned])
+		p = p[aligned:]
+	}
+	if len(p) == 0 {
+		return crc
+	}
+	return ppc64SlicingUpdateBy8(crc, archIeeeTable8, p)
+}