}

	var w1 writeCountingDiscard
	b1 := NewWriterSize(&w1, 1234)
	b1.WriteString(strings.Repeat("x", 1200))
	b1.Flush()
	if w1 != 1 {
		t.Fatalf("flush 1200 'x's: got %d writes, want 1", w1)
	}
	b1.WriteString(strings.Repeat("x", 89))
	if w1 != 1 {
		t.Fatalf("write 1200 + 89 'x's: got %d writes, want 1", w1)
	}

sliceForAppend(buf, 18*n/8) const b = 1 << 17 for i := 0; i < n; i += 4 { // b - [−2¹⁷+1, 2¹⁷] = [0, 2²⁸-1] w0 := b - fieldCenteredMod(r[i]) v[0] = byte(w0 << 0) v[1] = byte(w0 >> 8) v[2] = byte(w0 >> 16) w1 := b - fieldCenteredMod(r[i+1]) v[2] |= byte(w1 << 2) v[3] = byte(w1 >> 6) v[4] = byte(w1 >> 14) w2 := b - fieldCenteredMod(r[i+2]) v[4] |= byte(w2 << 4) v[5] = byte(w2 >> 4) v[6] = byte(w2 >> 12) w3 := b - fieldCenteredMod(r[i+3]) v[6] |= byte(w3 << 6) v[7] = byte(w3 >> 2) v[8] = byte(w3 >> 10)...

backup: V1 h(hgfe) VMOV V2.B16, V8.B16 VREV32 V4.B16, V4.B16 // prepare for using message in Byte format VREV32 V5.B16, V5.B16 VREV32 V6.B16, V6.B16 VREV32 V7.B16, V7.B16 VADD V16.S4, V4.S4, V9.S4 // V18(W0+K0...W3+K3) SHA256SU0 V5.S4, V4.S4 // V4: (su0(W1)+W0,...,su0(W4)+W3) HASHUPDATE // H4 VADD V17.S4, V5.S4, V9.S4 // V18(W4+K4...W7+K7) SHA256SU0 V6.S4, V5.S4 // V5: (su0(W5)+W4,...,su0(W8)+W7) SHA256SU1 V7.S4, V6.S4, V4.S4 // V4: W16-W19 HASHUPDATE // H8 VADD V18.S4, V6.S4, V9.S4 // V18(W8+K8...W11+K11)...