Add gops agent

vendor/golang.org/x/arch/ppc64/ppc64asm/field.go

@@ -0,0 +1,84 @@
+// 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 ppc64asm
+
+import (
+	"fmt"
+	"strings"
+)
+
+// A BitField is a bit-field in a 32-bit word.
+// Bits are counted from 0 from the MSB to 31 as the LSB.
+type BitField struct {
+	Offs uint8 // the offset of the left-most bit.
+	Bits uint8 // length in bits.
+}
+
+func (b BitField) String() string {
+	if b.Bits > 1 {
+		return fmt.Sprintf("[%d:%d]", b.Offs, int(b.Offs+b.Bits)-1)
+	} else if b.Bits == 1 {
+		return fmt.Sprintf("[%d]", b.Offs)
+	} else {
+		return fmt.Sprintf("[%d, len=0]", b.Offs)
+	}
+}
+
+// Parse extracts the bitfield b from i, and return it as an unsigned integer.
+// Parse will panic if b is invalid.
+func (b BitField) Parse(i uint32) uint32 {
+	if b.Bits > 32 || b.Bits == 0 || b.Offs > 31 || b.Offs+b.Bits > 32 {
+		panic(fmt.Sprintf("invalid bitfiled %v", b))
+	}
+	return (i >> (32 - b.Offs - b.Bits)) & ((1 << b.Bits) - 1)
+}
+
+// ParseSigned extracts the bitfield b from i, and return it as a signed integer.
+// ParseSigned will panic if b is invalid.
+func (b BitField) ParseSigned(i uint32) int32 {
+	u := int32(b.Parse(i))
+	return u << (32 - b.Bits) >> (32 - b.Bits)
+}
+
+// BitFields is a series of BitFields representing a single number.
+type BitFields []BitField
+
+func (bs BitFields) String() string {
+	ss := make([]string, len(bs))
+	for i, bf := range bs {
+		ss[i] = bf.String()
+	}
+	return fmt.Sprintf("<%s>", strings.Join(ss, "|"))
+}
+
+func (bs *BitFields) Append(b BitField) {
+	*bs = append(*bs, b)
+}
+
+// parse extracts the bitfields from i, concatenate them and return the result
+// as an unsigned integer and the total length of all the bitfields.
+// parse will panic if any bitfield in b is invalid, but it doesn't check if
+// the sequence of bitfields is reasonable.
+func (bs BitFields) parse(i uint32) (u uint32, Bits uint8) {
+	for _, b := range bs {
+		u = (u << b.Bits) | b.Parse(i)
+		Bits += b.Bits
+	}
+	return u, Bits
+}
+
+// Parse extracts the bitfields from i, concatenate them and return the result
+// as an unsigned integer. Parse will panic if any bitfield in b is invalid.
+func (bs BitFields) Parse(i uint32) uint32 {
+	u, _ := bs.parse(i)
+	return u
+}
+
+// Parse extracts the bitfields from i, concatenate them and return the result
+// as a signed integer. Parse will panic if any bitfield in b is invalid.
+func (bs BitFields) ParseSigned(i uint32) int32 {
+	u, l := bs.parse(i)
+	return int32(u) << (32 - l) >> (32 - l)
+}