Golang cmd-compile-internal-gc.Prog模块，常用函数和类-面圈网

作者：achand 项目：g

func ginsnop() {
	p := gc.Prog(s390x.AOR)
	p.From.Type = obj.TYPE_REG
	p.From.Reg = int16(s390x.REG_R0)
	p.To.Type = obj.TYPE_REG
	p.To.Reg = int16(s390x.REG_R0)
}

作者：achand 项目：g

// push pushes v onto the floating-point stack.  v must be in a register.
func push(s *gc.SSAGenState, v *ssa.Value) {
	p := gc.Prog(x86.AFMOVD)
	p.From.Type = obj.TYPE_REG
	p.From.Reg = s.SSEto387[v.Reg()]
	p.To.Type = obj.TYPE_REG
	p.To.Reg = x86.REG_F0
}

作者：kuangchanglan 项目：g

func ginsnop() {
	p := gc.Prog(mips.ANOR)
	p.From.Type = obj.TYPE_REG
	p.From.Reg = mips.REG_R0
	p.To.Type = obj.TYPE_REG
	p.To.Reg = mips.REG_R0
}

作者：duhaibo040 项目：go-

// opregreg emits instructions for
//     dest := dest(To) op src(From)
// and also returns the created obj.Prog so it
// may be further adjusted (offset, scale, etc).
func opregreg(op obj.As, dest, src int16) *obj.Prog {
	p := gc.Prog(op)
	p.From.Type = obj.TYPE_REG
	p.To.Type = obj.TYPE_REG
	p.To.Reg = dest
	p.From.Reg = src
	return p
}

作者：kuangchanglan 项目：g

// opregregimm emits instructions for
//	dest := src(From) op off
// and also returns the created obj.Prog so it
// may be further adjusted (offset, scale, etc).
func opregregimm(op obj.As, dest, src int16, off int64) *obj.Prog {
	p := gc.Prog(op)
	p.From.Type = obj.TYPE_CONST
	p.From.Offset = off
	p.Reg = src
	p.To.Reg = dest
	p.To.Type = obj.TYPE_REG
	return p
}

作者：achand 项目：g

func ssaGenISEL(v *ssa.Value, cr int64, r1, r2 int16) {
	r := v.Reg()
	p := gc.Prog(ppc64.AISEL)
	p.To.Type = obj.TYPE_REG
	p.To.Reg = r
	p.Reg = r1
	p.From3 = &obj.Addr{Type: obj.TYPE_REG, Reg: r2}
	p.From.Type = obj.TYPE_CONST
	p.From.Offset = cr
}

作者：achand 项目：g

// flush387 removes all entries from the 387 floating-point stack.
func flush387(s *gc.SSAGenState) {
	for k := range s.SSEto387 {
		p := gc.Prog(x86.AFMOVDP)
		p.From.Type = obj.TYPE_REG
		p.From.Reg = x86.REG_F0
		p.To.Type = obj.TYPE_REG
		p.To.Reg = x86.REG_F0
		delete(s.SSEto387, k)
	}
}

作者：Greento 项目：g

// generate one instruction:
//	as f, t
func rawgins(as obj.As, f *gc.Node, t *gc.Node) *obj.Prog {
	// self move check
	// TODO(mundaym): use sized math and extend to MOVB, MOVWZ etc.
	switch as {
	case s390x.AMOVD, s390x.AFMOVS, s390x.AFMOVD:
		if f != nil && t != nil &&
			f.Op == gc.OREGISTER && t.Op == gc.OREGISTER &&
			f.Reg == t.Reg {
			return nil
		}
	}

	p := gc.Prog(as)
	gc.Naddr(&p.From, f)
	gc.Naddr(&p.To, t)

	switch as {
	// Bad things the front end has done to us. Crash to find call stack.
	case s390x.ACMP, s390x.ACMPU:
		if p.From.Type == obj.TYPE_MEM || p.To.Type == obj.TYPE_MEM {
			gc.Debug['h'] = 1
			gc.Fatalf("bad inst: %v", p)
		}
	}

	if gc.Debug['g'] != 0 {
		fmt.Printf("%v\n", p)
	}

	w := int32(0)
	switch as {
	case s390x.AMOVB, s390x.AMOVBZ:
		w = 1

	case s390x.AMOVH, s390x.AMOVHZ:
		w = 2

	case s390x.AMOVW, s390x.AMOVWZ:
		w = 4

	case s390x.AMOVD:
		if p.From.Type == obj.TYPE_CONST || p.From.Type == obj.TYPE_ADDR {
			break
		}
		w = 8
	}

	if w != 0 && ((f != nil && p.From.Width < int64(w)) || (t != nil && p.To.Type != obj.TYPE_REG && p.To.Width > int64(w))) {
		gc.Dump("f", f)
		gc.Dump("t", t)
		gc.Fatalf("bad width: %v (%d, %d)\n", p, p.From.Width, p.To.Width)
	}

	return p
}

作者：achand 项目：g

// genshift generates a Prog for r = r0 op (r1 shifted by s)
func genshift(as obj.As, r0, r1, r int16, typ int64, s int64) *obj.Prog {
	p := gc.Prog(as)
	p.From.Type = obj.TYPE_SHIFT
	p.From.Offset = int64(makeshift(r1, typ, s))
	p.Reg = r0
	if r != 0 {
		p.To.Type = obj.TYPE_REG
		p.To.Reg = r
	}
	return p
}

作者：duhaibo040 项目：go-

func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
	s.SetLineno(b.Line)

	switch b.Kind {
	case ssa.BlockCall:
		if b.Succs[0] != next {
			p := gc.Prog(obj.AJMP)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
		}
	case ssa.BlockRet:
		gc.Prog(obj.ARET)
	case ssa.BlockARMLT:
		p := gc.Prog(arm.ABGE)
		p.To.Type = obj.TYPE_BRANCH
		s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
		p = gc.Prog(obj.AJMP)
		p.To.Type = obj.TYPE_BRANCH
		s.Branches = append(s.Branches, gc.Branch{p, b.Succs[1]})
	}
}

作者：wycharr 项目：g

/*
 * generate one instruction:
 *	as f, t
 */
func rawgins(as int, f *gc.Node, t *gc.Node) *obj.Prog {
	// TODO(austin): Add self-move test like in 6g (but be careful
	// of truncation moves)

	p := gc.Prog(as)
	gc.Naddr(&p.From, f)
	gc.Naddr(&p.To, t)

	switch as {
	// Bad things the front end has done to us. Crash to find call stack.
	case s390x.AAND, s390x.AMULLD:
		if p.From.Type == obj.TYPE_CONST {
			gc.Debug['h'] = 1
			gc.Fatalf("bad inst: %v", p)
		}
	case s390x.ACMP, s390x.ACMPU:
		if p.From.Type == obj.TYPE_MEM || p.To.Type == obj.TYPE_MEM {
			gc.Debug['h'] = 1
			gc.Fatalf("bad inst: %v", p)
		}
	}

	if gc.Debug['g'] != 0 {
		fmt.Printf("%v\n", p)
	}

	w := int32(0)
	switch as {
	case s390x.AMOVB, s390x.AMOVBZ:
		w = 1

	case s390x.AMOVH, s390x.AMOVHZ:
		w = 2

	case s390x.AMOVW, s390x.AMOVWZ:
		w = 4

	case s390x.AMOVD:
		if p.From.Type == obj.TYPE_CONST || p.From.Type == obj.TYPE_ADDR {
			break
		}
		w = 8
	}

	if w != 0 && ((f != nil && p.From.Width < int64(w)) || (t != nil && p.To.Type != obj.TYPE_REG && p.To.Width > int64(w))) {
		gc.Dump("f", f)
		gc.Dump("t", t)
		gc.Fatalf("bad width: %v (%d, %d)\n", p, p.From.Width, p.To.Width)
	}

	return p
}

作者：wycharr 项目：g

// gmvc tries to move f to t using a mvc instruction.
// If successful it returns true, otherwise it returns false.
func gmvc(f, t *gc.Node) bool {
	ft := int(gc.Simsimtype(f.Type))
	tt := int(gc.Simsimtype(t.Type))

	if ft != tt {
		return false
	}

	if f.Op != gc.OINDREG || t.Op != gc.OINDREG {
		return false
	}

	if f.Xoffset < 0 || f.Xoffset >= 4096 {
		return false
	}

	if t.Xoffset < 0 || t.Xoffset >= 4096 {
		return false
	}

	var len int64
	switch ft {
	case gc.TUINT8, gc.TINT8, gc.TBOOL:
		len = 1
	case gc.TUINT16, gc.TINT16:
		len = 2
	case gc.TUINT32, gc.TINT32, gc.TFLOAT32:
		len = 4
	case gc.TUINT64, gc.TINT64, gc.TFLOAT64, gc.TPTR64:
		len = 8
	case gc.TUNSAFEPTR:
		len = int64(gc.Widthptr)
	default:
		return false
	}

	p := gc.Prog(s390x.AMVC)
	gc.Naddr(&p.From, f)
	gc.Naddr(&p.To, t)
	p.From3 = new(obj.Addr)
	p.From3.Offset = len
	p.From3.Type = obj.TYPE_CONST
	return true
}

作者：achand 项目：g

// popAndSave pops a value off of the floating-point stack and stores
// it in the reigster assigned to v.
func popAndSave(s *gc.SSAGenState, v *ssa.Value) {
	r := v.Reg()
	if _, ok := s.SSEto387[r]; ok {
		// Pop value, write to correct register.
		p := gc.Prog(x86.AFMOVDP)
		p.From.Type = obj.TYPE_REG
		p.From.Reg = x86.REG_F0
		p.To.Type = obj.TYPE_REG
		p.To.Reg = s.SSEto387[v.Reg()] + 1
	} else {
		// Don't actually pop value. This 387 register is now the
		// new home for the not-yet-assigned-a-home SSE register.
		// Increase the register mapping of all other registers by one.
		for rSSE, r387 := range s.SSEto387 {
			s.SSEto387[rSSE] = r387 + 1
		}
		s.SSEto387[r] = x86.REG_F0
	}
}

作者：arnold 项目：g

/*
 * generate one instruction:
 *	as f, t
 */
func rawgins(as int, f *gc.Node, t *gc.Node) *obj.Prog {
	// TODO(austin): Add self-move test like in 6g (but be careful
	// of truncation moves)

	p := gc.Prog(as)
	gc.Naddr(&p.From, f)
	gc.Naddr(&p.To, t)

	switch as {
	case obj.ACALL:
		if p.To.Type == obj.TYPE_REG && p.To.Reg != ppc64.REG_CTR {
			// Allow front end to emit CALL REG, and rewrite into MOV REG, CTR; CALL CTR.
			if gc.Ctxt.Flag_dynlink {
				// Make sure function pointer is in R12 as well when
				// dynamically linking Go.
				// TODO(mwhudson): it would obviously be better to
				// change the register allocation to put the value in
				// R12 already, but I don't know how to do that.
				q := gc.Prog(as)
				q.As = ppc64.AMOVD
				q.From = p.To
				q.To.Type = obj.TYPE_REG
				q.To.Reg = ppc64.REG_R12
			}
			pp := gc.Prog(as)
			pp.From = p.From
			pp.To.Type = obj.TYPE_REG
			pp.To.Reg = ppc64.REG_CTR

			p.As = ppc64.AMOVD
			p.From = p.To
			p.To.Type = obj.TYPE_REG
			p.To.Reg = ppc64.REG_CTR

			if gc.Debug['g'] != 0 {
				fmt.Printf("%v\n", p)
				fmt.Printf("%v\n", pp)
			}

			return pp
		}

	// Bad things the front end has done to us. Crash to find call stack.
	case ppc64.AAND, ppc64.AMULLD:
		if p.From.Type == obj.TYPE_CONST {
			gc.Debug['h'] = 1
			gc.Fatalf("bad inst: %v", p)
		}
	case ppc64.ACMP, ppc64.ACMPU:
		if p.From.Type == obj.TYPE_MEM || p.To.Type == obj.TYPE_MEM {
			gc.Debug['h'] = 1
			gc.Fatalf("bad inst: %v", p)
		}
	}

	if gc.Debug['g'] != 0 {
		fmt.Printf("%v\n", p)
	}

	w := int32(0)
	switch as {
	case ppc64.AMOVB,
		ppc64.AMOVBU,
		ppc64.AMOVBZ,
		ppc64.AMOVBZU:
		w = 1

	case ppc64.AMOVH,
		ppc64.AMOVHU,
		ppc64.AMOVHZ,
		ppc64.AMOVHZU:
		w = 2

	case ppc64.AMOVW,
		ppc64.AMOVWU,
		ppc64.AMOVWZ,
		ppc64.AMOVWZU:
		w = 4

	case ppc64.AMOVD,
		ppc64.AMOVDU:
		if p.From.Type == obj.TYPE_CONST || p.From.Type == obj.TYPE_ADDR {
			break
		}
		w = 8
	}

	if w != 0 && ((f != nil && p.From.Width < int64(w)) || (t != nil && p.To.Type != obj.TYPE_REG && p.To.Width > int64(w))) {
		gc.Dump("f", f)
		gc.Dump("t", t)
		gc.Fatalf("bad width: %v (%d, %d)\n", p, p.From.Width, p.To.Width)
	}

	return p
}

作者：srei 项目：g

/*
 * generate one instruction:
 *	as f, t
 */
func gins(as int, f *gc.Node, t *gc.Node) *obj.Prog {
	if as == x86.AFMOVF && f != nil && f.Op == gc.OREGISTER && t != nil && t.Op == gc.OREGISTER {
		gc.Fatalf("gins MOVF reg, reg")
	}
	if as == x86.ACVTSD2SS && f != nil && f.Op == gc.OLITERAL {
		gc.Fatalf("gins CVTSD2SS const")
	}
	if as == x86.AMOVSD && t != nil && t.Op == gc.OREGISTER && t.Reg == x86.REG_F0 {
		gc.Fatalf("gins MOVSD into F0")
	}

	if as == x86.AMOVL && f != nil && f.Op == gc.OADDR && f.Left.Op == gc.ONAME && f.Left.Class != gc.PEXTERN && f.Left.Class != gc.PFUNC {
		// Turn MOVL $xxx(FP/SP) into LEAL xxx.
		// These should be equivalent but most of the backend
		// only expects to see LEAL, because that's what we had
		// historically generated. Various hidden assumptions are baked in by now.
		as = x86.ALEAL
		f = f.Left
	}

	switch as {
	case x86.AMOVB,
		x86.AMOVW,
		x86.AMOVL:
		if f != nil && t != nil && samaddr(f, t) {
			return nil
		}

	case x86.ALEAL:
		if f != nil && gc.Isconst(f, gc.CTNIL) {
			gc.Fatalf("gins LEAL nil %v", f.Type)
		}
	}

	p := gc.Prog(as)
	gc.Naddr(&p.From, f)
	gc.Naddr(&p.To, t)

	if gc.Debug['g'] != 0 {
		fmt.Printf("%v\n", p)
	}

	w := 0
	switch as {
	case x86.AMOVB:
		w = 1

	case x86.AMOVW:
		w = 2

	case x86.AMOVL:
		w = 4
	}

	if true && w != 0 && f != nil && (p.From.Width > int64(w) || p.To.Width > int64(w)) {
		gc.Dump("bad width from:", f)
		gc.Dump("bad width to:", t)
		gc.Fatalf("bad width: %v (%d, %d)\n", p, p.From.Width, p.To.Width)
	}

	if p.To.Type == obj.TYPE_ADDR && w > 0 {
		gc.Fatalf("bad use of addr: %v", p)
	}

	return p
}

作者：Mokole 项目：g

func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
	s.SetLineno(v.Line)
	switch v.Op {
	case ssa.OpAMD64ADDQ, ssa.OpAMD64ADDL:
		r := gc.SSARegNum(v)
		r1 := gc.SSARegNum(v.Args[0])
		r2 := gc.SSARegNum(v.Args[1])
		switch {
		case r == r1:
			p := gc.Prog(v.Op.Asm())
			p.From.Type = obj.TYPE_REG
			p.From.Reg = r2
			p.To.Type = obj.TYPE_REG
			p.To.Reg = r
		case r == r2:
			p := gc.Prog(v.Op.Asm())
			p.From.Type = obj.TYPE_REG
			p.From.Reg = r1
			p.To.Type = obj.TYPE_REG
			p.To.Reg = r
		default:
			var asm obj.As
			if v.Op == ssa.OpAMD64ADDQ {
				asm = x86.ALEAQ
			} else {
				asm = x86.ALEAL
			}
			p := gc.Prog(asm)
			p.From.Type = obj.TYPE_MEM
			p.From.Reg = r1
			p.From.Scale = 1
			p.From.Index = r2
			p.To.Type = obj.TYPE_REG
			p.To.Reg = r
		}
	// 2-address opcode arithmetic
	case ssa.OpAMD64SUBQ, ssa.OpAMD64SUBL,
		ssa.OpAMD64MULQ, ssa.OpAMD64MULL,
		ssa.OpAMD64ANDQ, ssa.OpAMD64ANDL,
		ssa.OpAMD64ORQ, ssa.OpAMD64ORL,
		ssa.OpAMD64XORQ, ssa.OpAMD64XORL,
		ssa.OpAMD64SHLQ, ssa.OpAMD64SHLL,
		ssa.OpAMD64SHRQ, ssa.OpAMD64SHRL, ssa.OpAMD64SHRW, ssa.OpAMD64SHRB,
		ssa.OpAMD64SARQ, ssa.OpAMD64SARL, ssa.OpAMD64SARW, ssa.OpAMD64SARB,
		ssa.OpAMD64ADDSS, ssa.OpAMD64ADDSD, ssa.OpAMD64SUBSS, ssa.OpAMD64SUBSD,
		ssa.OpAMD64MULSS, ssa.OpAMD64MULSD, ssa.OpAMD64DIVSS, ssa.OpAMD64DIVSD,
		ssa.OpAMD64PXOR:
		r := gc.SSARegNum(v)
		if r != gc.SSARegNum(v.Args[0]) {
			v.Fatalf("input[0] and output not in same register %s", v.LongString())
		}
		opregreg(v.Op.Asm(), r, gc.SSARegNum(v.Args[1]))

	case ssa.OpAMD64DIVQU, ssa.OpAMD64DIVLU, ssa.OpAMD64DIVWU:
		// Arg[0] (the dividend) is in AX.
		// Arg[1] (the divisor) can be in any other register.
		// Result[0] (the quotient) is in AX.
		// Result[1] (the remainder) is in DX.
		r := gc.SSARegNum(v.Args[1])

		// Zero extend dividend.
		c := gc.Prog(x86.AXORL)
		c.From.Type = obj.TYPE_REG
		c.From.Reg = x86.REG_DX
		c.To.Type = obj.TYPE_REG
		c.To.Reg = x86.REG_DX

		// Issue divide.
		p := gc.Prog(v.Op.Asm())
		p.From.Type = obj.TYPE_REG
		p.From.Reg = r

	case ssa.OpAMD64DIVQ, ssa.OpAMD64DIVL, ssa.OpAMD64DIVW:
		// Arg[0] (the dividend) is in AX.
		// Arg[1] (the divisor) can be in any other register.
		// Result[0] (the quotient) is in AX.
		// Result[1] (the remainder) is in DX.
		r := gc.SSARegNum(v.Args[1])

		// CPU faults upon signed overflow, which occurs when the most
		// negative int is divided by -1. Handle divide by -1 as a special case.
		var c *obj.Prog
		switch v.Op {
		case ssa.OpAMD64DIVQ:
			c = gc.Prog(x86.ACMPQ)
		case ssa.OpAMD64DIVL:
			c = gc.Prog(x86.ACMPL)
		case ssa.OpAMD64DIVW:
			c = gc.Prog(x86.ACMPW)
		}
		c.From.Type = obj.TYPE_REG
		c.From.Reg = r
		c.To.Type = obj.TYPE_CONST
		c.To.Offset = -1
		j1 := gc.Prog(x86.AJEQ)
		j1.To.Type = obj.TYPE_BRANCH

		// Sign extend dividend.
		switch v.Op {
		case ssa.OpAMD64DIVQ:
//.........这里部分代码省略.........

作者：duhaibo040 项目：go-

func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
	s.SetLineno(v.Line)
	switch v.Op {
	case ssa.OpAMD64ADDQ, ssa.OpAMD64ADDL, ssa.OpAMD64ADDW:
		r := gc.SSARegNum(v)
		r1 := gc.SSARegNum(v.Args[0])
		r2 := gc.SSARegNum(v.Args[1])
		switch {
		case r == r1:
			p := gc.Prog(v.Op.Asm())
			p.From.Type = obj.TYPE_REG
			p.From.Reg = r2
			p.To.Type = obj.TYPE_REG
			p.To.Reg = r
		case r == r2:
			p := gc.Prog(v.Op.Asm())
			p.From.Type = obj.TYPE_REG
			p.From.Reg = r1
			p.To.Type = obj.TYPE_REG
			p.To.Reg = r
		default:
			var asm obj.As
			switch v.Op {
			case ssa.OpAMD64ADDQ:
				asm = x86.ALEAQ
			case ssa.OpAMD64ADDL:
				asm = x86.ALEAL
			case ssa.OpAMD64ADDW:
				asm = x86.ALEAL
			}
			p := gc.Prog(asm)
			p.From.Type = obj.TYPE_MEM
			p.From.Reg = r1
			p.From.Scale = 1
			p.From.Index = r2
			p.To.Type = obj.TYPE_REG
			p.To.Reg = r
		}
	// 2-address opcode arithmetic, symmetric
	case ssa.OpAMD64ADDB, ssa.OpAMD64ADDSS, ssa.OpAMD64ADDSD,
		ssa.OpAMD64ANDQ, ssa.OpAMD64ANDL, ssa.OpAMD64ANDW, ssa.OpAMD64ANDB,
		ssa.OpAMD64ORQ, ssa.OpAMD64ORL, ssa.OpAMD64ORW, ssa.OpAMD64ORB,
		ssa.OpAMD64XORQ, ssa.OpAMD64XORL, ssa.OpAMD64XORW, ssa.OpAMD64XORB,
		ssa.OpAMD64MULQ, ssa.OpAMD64MULL, ssa.OpAMD64MULW, ssa.OpAMD64MULB,
		ssa.OpAMD64MULSS, ssa.OpAMD64MULSD, ssa.OpAMD64PXOR:
		r := gc.SSARegNum(v)
		x := gc.SSARegNum(v.Args[0])
		y := gc.SSARegNum(v.Args[1])
		if x != r && y != r {
			opregreg(moveByType(v.Type), r, x)
			x = r
		}
		p := gc.Prog(v.Op.Asm())
		p.From.Type = obj.TYPE_REG
		p.To.Type = obj.TYPE_REG
		p.To.Reg = r
		if x == r {
			p.From.Reg = y
		} else {
			p.From.Reg = x
		}
	// 2-address opcode arithmetic, not symmetric
	case ssa.OpAMD64SUBQ, ssa.OpAMD64SUBL, ssa.OpAMD64SUBW, ssa.OpAMD64SUBB:
		r := gc.SSARegNum(v)
		x := gc.SSARegNum(v.Args[0])
		y := gc.SSARegNum(v.Args[1])
		var neg bool
		if y == r {
			// compute -(y-x) instead
			x, y = y, x
			neg = true
		}
		if x != r {
			opregreg(moveByType(v.Type), r, x)
		}
		opregreg(v.Op.Asm(), r, y)

		if neg {
			if v.Op == ssa.OpAMD64SUBQ {
				p := gc.Prog(x86.ANEGQ)
				p.To.Type = obj.TYPE_REG
				p.To.Reg = r
			} else { // Avoids partial registers write
				p := gc.Prog(x86.ANEGL)
				p.To.Type = obj.TYPE_REG
				p.To.Reg = r
			}
		}
	case ssa.OpAMD64SUBSS, ssa.OpAMD64SUBSD, ssa.OpAMD64DIVSS, ssa.OpAMD64DIVSD:
		r := gc.SSARegNum(v)
		x := gc.SSARegNum(v.Args[0])
		y := gc.SSARegNum(v.Args[1])
		if y == r && x != r {
			// r/y := x op r/y, need to preserve x and rewrite to
			// r/y := r/y op x15
			x15 := int16(x86.REG_X15)
			// register move y to x15
			// register move x to y
			// rename y with x15
			opregreg(moveByType(v.Type), x15, y)
//.........这里部分代码省略.........

作者：wheelcomple 项目：go-

/*
 * generate one instruction:
 *	as f, t
 */
func gins(as int, f *gc.Node, t *gc.Node) *obj.Prog {
	//	Node nod;
	//	int32 v;

	if f != nil && f.Op == gc.OINDEX {
		gc.Fatal("gins OINDEX not implemented")
	}

	//		gc.Regalloc(&nod, &regnode, Z);
	//		v = constnode.vconst;
	//		gc.Cgen(f->right, &nod);
	//		constnode.vconst = v;
	//		idx.reg = nod.reg;
	//		gc.Regfree(&nod);
	if t != nil && t.Op == gc.OINDEX {
		gc.Fatal("gins OINDEX not implemented")
	}

	//		gc.Regalloc(&nod, &regnode, Z);
	//		v = constnode.vconst;
	//		gc.Cgen(t->right, &nod);
	//		constnode.vconst = v;
	//		idx.reg = nod.reg;
	//		gc.Regfree(&nod);

	p := gc.Prog(as)
	gc.Naddr(&p.From, f)
	gc.Naddr(&p.To, t)

	switch as {
	case arm.ABL:
		if p.To.Type == obj.TYPE_REG {
			p.To.Type = obj.TYPE_MEM
		}

	case arm.ACMP, arm.ACMPF, arm.ACMPD:
		if t != nil {
			if f.Op != gc.OREGISTER {
				/* generate a comparison
				TODO(kaib): one of the args can actually be a small constant. relax the constraint and fix call sites.
				*/
				gc.Fatal("bad operands to gcmp")
			}
			p.From = p.To
			p.To = obj.Addr{}
			raddr(f, p)
		}

	case arm.AMULU:
		if f != nil && f.Op != gc.OREGISTER {
			gc.Fatal("bad operands to mul")
		}

	case arm.AMOVW:
		if (p.From.Type == obj.TYPE_MEM || p.From.Type == obj.TYPE_ADDR || p.From.Type == obj.TYPE_CONST) && (p.To.Type == obj.TYPE_MEM || p.To.Type == obj.TYPE_ADDR) {
			gc.Fatal("gins double memory")
		}

	case arm.AADD:
		if p.To.Type == obj.TYPE_MEM {
			gc.Fatal("gins arith to mem")
		}

	case arm.ARSB:
		if p.From.Type == obj.TYPE_NONE {
			gc.Fatal("rsb with no from")
		}
	}

	if gc.Debug['g'] != 0 {
		fmt.Printf("%v\n", p)
	}
	return p
}

作者：Harvey-O 项目：g

func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
	s.SetLineno(b.Line)

	switch b.Kind {
	case ssa.BlockPlain:
		if b.Succs[0].Block() != next {
			p := gc.Prog(obj.AJMP)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
		}
	case ssa.BlockDefer:
		// defer returns in R1:
		// 0 if we should continue executing
		// 1 if we should jump to deferreturn call
		p := gc.Prog(mips.ABNE)
		p.From.Type = obj.TYPE_REG
		p.From.Reg = mips.REGZERO
		p.Reg = mips.REG_R1
		p.To.Type = obj.TYPE_BRANCH
		s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
		if b.Succs[0].Block() != next {
			p := gc.Prog(obj.AJMP)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
		}
	case ssa.BlockExit:
		gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here
	case ssa.BlockRet:
		gc.Prog(obj.ARET)
	case ssa.BlockRetJmp:
		p := gc.Prog(obj.ARET)
		p.To.Type = obj.TYPE_MEM
		p.To.Name = obj.NAME_EXTERN
		p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))
	case ssa.BlockMIPSEQ, ssa.BlockMIPSNE,
		ssa.BlockMIPSLTZ, ssa.BlockMIPSGEZ,
		ssa.BlockMIPSLEZ, ssa.BlockMIPSGTZ,
		ssa.BlockMIPSFPT, ssa.BlockMIPSFPF:
		jmp := blockJump[b.Kind]
		var p *obj.Prog
		switch next {
		case b.Succs[0].Block():
			p = gc.Prog(jmp.invasm)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
		case b.Succs[1].Block():
			p = gc.Prog(jmp.asm)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
		default:
			p = gc.Prog(jmp.asm)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
			q := gc.Prog(obj.AJMP)
			q.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()})
		}
		if !b.Control.Type.IsFlags() {
			p.From.Type = obj.TYPE_REG
			p.From.Reg = b.Control.Reg()
		}
	default:
		b.Fatalf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
	}
}

作者：achand 项目：g

func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
	s.SetLineno(b.Line)

	switch b.Kind {
	case ssa.BlockPlain:
		if b.Succs[0].Block() != next {
			p := gc.Prog(obj.AJMP)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
		}

	case ssa.BlockDefer:
		// defer returns in R0:
		// 0 if we should continue executing
		// 1 if we should jump to deferreturn call
		p := gc.Prog(arm.ACMP)
		p.From.Type = obj.TYPE_CONST
		p.From.Offset = 0
		p.Reg = arm.REG_R0
		p = gc.Prog(arm.ABNE)
		p.To.Type = obj.TYPE_BRANCH
		s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
		if b.Succs[0].Block() != next {
			p := gc.Prog(obj.AJMP)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
		}

	case ssa.BlockExit:
		gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here

	case ssa.BlockRet:
		gc.Prog(obj.ARET)

	case ssa.BlockRetJmp:
		p := gc.Prog(obj.ARET)
		p.To.Type = obj.TYPE_MEM
		p.To.Name = obj.NAME_EXTERN
		p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))

	case ssa.BlockARMEQ, ssa.BlockARMNE,
		ssa.BlockARMLT, ssa.BlockARMGE,
		ssa.BlockARMLE, ssa.BlockARMGT,
		ssa.BlockARMULT, ssa.BlockARMUGT,
		ssa.BlockARMULE, ssa.BlockARMUGE:
		jmp := blockJump[b.Kind]
		var p *obj.Prog
		switch next {
		case b.Succs[0].Block():
			p = gc.Prog(jmp.invasm)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
		case b.Succs[1].Block():
			p = gc.Prog(jmp.asm)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
		default:
			p = gc.Prog(jmp.asm)
			p.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
			q := gc.Prog(obj.AJMP)
			q.To.Type = obj.TYPE_BRANCH
			s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()})
		}

	default:
		b.Fatalf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
	}
}

Golang cmd-compile-internal-gc.Prog类(方法)实例源码