path: root/vendor/github.com/google/gops/internal/obj/s390x/objz.go

// Based on cmd/internal/obj/ppc64/obj9.go.
//
//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
//	Portions Copyright © 1997-1999 Vita Nuova Limited
//	Portions Copyright © 2000-2008 Vita Nuova Holdings Limited (www.vitanuova.com)
//	Portions Copyright © 2004,2006 Bruce Ellis
//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
//	Revisions Copyright © 2000-2008 Lucent Technologies Inc. and others
//	Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package s390x

import (
	"fmt"
	"math"

	"github.com/google/gops/internal/obj"
	"github.com/google/gops/internal/sys"
)

func progedit(ctxt *obj.Link, p *obj.Prog) {
	p.From.Class = 0
	p.To.Class = 0

	// Rewrite BR/BL to symbol as TYPE_BRANCH.
	switch p.As {
	case ABR,
		ABL,
		obj.ARET,
		obj.ADUFFZERO,
		obj.ADUFFCOPY:
		if p.To.Sym != nil {
			p.To.Type = obj.TYPE_BRANCH
		}
	}

	// Rewrite float constants to values stored in memory unless they are +0.
	switch p.As {
	case AFMOVS:
		if p.From.Type == obj.TYPE_FCONST {
			f32 := float32(p.From.Val.(float64))
			i32 := math.Float32bits(f32)
			if i32 == 0 { // +0
				break
			}
			literal := fmt.Sprintf("$f32.%08x", i32)
			s := obj.Linklookup(ctxt, literal, 0)
			s.Size = 4
			p.From.Type = obj.TYPE_MEM
			p.From.Sym = s
			p.From.Sym.Set(obj.AttrLocal, true)
			p.From.Name = obj.NAME_EXTERN
			p.From.Offset = 0
		}

	case AFMOVD:
		if p.From.Type == obj.TYPE_FCONST {
			i64 := math.Float64bits(p.From.Val.(float64))
			if i64 == 0 { // +0
				break
			}
			literal := fmt.Sprintf("$f64.%016x", i64)
			s := obj.Linklookup(ctxt, literal, 0)
			s.Size = 8
			p.From.Type = obj.TYPE_MEM
			p.From.Sym = s
			p.From.Sym.Set(obj.AttrLocal, true)
			p.From.Name = obj.NAME_EXTERN
			p.From.Offset = 0
		}

		// put constants not loadable by LOAD IMMEDIATE into memory
	case AMOVD:
		if p.From.Type == obj.TYPE_CONST {
			val := p.From.Offset
			if int64(int32(val)) != val &&
				int64(uint32(val)) != val &&
				int64(uint64(val)&(0xffffffff<<32)) != val {
				literal := fmt.Sprintf("$i64.%016x", uint64(p.From.Offset))
				s := obj.Linklookup(ctxt, literal, 0)
				s.Size = 8
				p.From.Type = obj.TYPE_MEM
				p.From.Sym = s
				p.From.Sym.Set(obj.AttrLocal, true)
				p.From.Name = obj.NAME_EXTERN
				p.From.Offset = 0
			}
		}
	}

	// Rewrite SUB constants into ADD.
	switch p.As {
	case ASUBC:
		if p.From.Type == obj.TYPE_CONST && isint32(-p.From.Offset) {
			p.From.Offset =