return &CodeBlock{p.pos(), "", "", b.text}
}

type fenceBuilder struct {
	fence string
	info  string
	n     int
	text  []string
}

func (c *fenceBuilder) extend(p *parseState, s line) (line, bool) {
	var fence, info string
	var n int
	if t := s; t.trimFence(&fence, &info, &n) && strings.HasPrefix(fence, c.fence) && info == "" {
		return line{}, false
	}
	if !s.trimSpace(c.n, c.n, false) {

	// will clobber the test pattern created by the caller
	ADD	$(1024*8), X2

	// Ask signaller to setgid
	MOV	$1, X5
	FENCE
	MOVW	X5, ·Baton(SB)
	FENCE

	// Wait for setgid completion
loop:
	FENCE
	MOVW	·Baton(SB), X5
	OR	X6, X6, X6	// hint that we're in a spin loop
	BNE	ZERO, X5, loop
	FENCE

	// Restore stack
	ADD	$(-1024*8), X2

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "textflag.h"

// func publicationBarrier()
TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
	FENCE

	"SRL",
	"SUB",
	"SRA",
	"JAL",
	"JALR",
	"BEQ",
	"BNE",
	"BLT",
	"BLTU",
	"BGE",
	"BGEU",
	"LW",
	"LWU",
	"LH",
	"LHU",
	"LB",
	"LBU",
	"SW",
	"SH",
	"SB",
	"FENCE",
	"FENCETSO",
	"PAUSE",
	"ADDIW",
	"SLLIW",
	"SRLIW",
	"SRAIW",
	"ADDW",
	"SLLW",
	"SRLW",
	"SUBW",
	"SRAW",
	"LD",
	"SD",
	"MUL",
	"MULH",
	"MULHU",
	"MULHSU",
	"MULW",

		t.Errorf("Branch test failed: %v\n%s", err, out)
	}
}

func TestPCAlign(t *testing.T) {
	dir := t.TempDir()
	tmpfile := filepath.Join(dir, "x.s")
	asm := `
TEXT _stub(SB),$0-0
	FENCE
	PCALIGN	$8
	FENCE
	RET
`
	if err := os.WriteFile(tmpfile, []byte(asm), 0644); err != nil {
		t.Fatal(err)
	}
	cmd := exec.Command(testenv.GoToolPath(t), "tool", "asm", "-o", filepath.Join(dir, "x.o"), "-S", tmpfile)

TEXT ·Load(SB),NOSPLIT|NOFRAME,$0-12
	MOV	ptr+0(FP), A0
	LRW	(A0), A0
	MOVW	A0, ret+8(FP)
	RET

// func Load8(ptr *uint8) uint8
TEXT ·Load8(SB),NOSPLIT|NOFRAME,$0-9
	MOV	ptr+0(FP), A0
	FENCE
	MOVBU	(A0), A1
	FENCE
	MOVB	A1, ret+8(FP)
	RET

// func Load64(ptr *uint64) uint64
TEXT ·Load64(SB),NOSPLIT|NOFRAME,$0-16
	MOV	ptr+0(FP), A0
	LRD	(A0), A0
	MOV	A0, ret+8(FP)
	RET

	MOV	$SYS_exit, T0
	ECALL
	WORD	$0	// crash

// func exitThread(wait *atomic.Uint32)
TEXT runtime·exitThread(SB),NOSPLIT|NOFRAME,$0-8
	MOV	wait+0(FP), A0
	// We're done using the stack.
	FENCE
	MOVW	ZERO, (A0)
	FENCE
	MOV	$0, A0	// exit code
	MOV	$SYS_thr_exit, T0
	ECALL
	JMP	0(PC)

// func open(name *byte, mode, perm int32) int32
TEXT runtime·open(SB),NOSPLIT|NOFRAME,$0-20
	MOV	name+0(FP), A0

	MOV	$SYS_exit_group, A7
	ECALL
	RET

// func exitThread(wait *atomic.Uint32)
TEXT runtime·exitThread(SB),NOSPLIT|NOFRAME,$0-8
	MOV	wait+0(FP), A0
	// We're done using the stack.
	FENCE
	MOVW	ZERO, (A0)
	FENCE
	MOV	$0, A0	// exit code
	MOV	$SYS_exit, A7
	ECALL
	JMP	0(PC)

// func open(name *byte, mode, perm int32) int32
TEXT runtime·open(SB),NOSPLIT|NOFRAME,$0-20
	MOV	$AT_FDCWD, A0
	MOV	name+0(FP), A1

			return
		}
	}
	if z < 4 {
		if uint(z) > 4 { // Not provable without disjunctions.
			return
		}
	}
}

// fence1–4 correspond to the four fence-post implications.

func fence1(b []int, x, y int) {
	// Test proofs that rely on fence-post implications.
	if x+1 > y {
		if x < y { // ERROR "Disproved Less64$"
			return
		}
	}
	if len(b) < cap(b) {
		// This eliminates the growslice path.

	AECALL
	ASCALL
	AEBREAK
	ASBREAK

	// 3.2.2: Trap-Return Instructions
	AMRET
	ASRET
	ADRET

	// 3.2.3: Wait for Interrupt
	AWFI

	// 4.2.1: Supervisor Memory-Management Fence Instruction
	ASFENCEVMA

	//
	// RISC-V Bit-Manipulation ISA-extensions (1.0)
	//

	// 1.1: Address Generation Instructions (Zba)
	AADDUW
	ASH1ADD
	ASH1ADDUW
	ASH2ADD
	ASH2ADDUW