diff --git a/ldpc_decoder.hh b/ldpc_decoder.hh
index aed39aa..8a6d2df 100644
--- a/ldpc_decoder.hh
+++ b/ldpc_decoder.hh
@@ -36,22 +36,22 @@ class LDPCDecoder
 	static const int W = M/D;
 	static const int PTY = R/D;
 	static const int MSG = K/D;
+	static const int VAR = N/D;
 	static const int CNC = TABLE::LINKS_MAX_CN - 2;
 	static const int BNL = (TABLE::LINKS_TOTAL + D-1) / D;
-	static const int LOC = (TABLE::LINKS_TOTAL - (2*R-1) + D-1) / D;
+	static const int LOC = (TABLE::LINKS_TOTAL + D-1) / D;
 
 	typedef SIMD<int8_t, SIMD_SIZE> TYPE;
 	typedef struct { uint16_t off; uint16_t shi; } Loc;
 	typedef uint32_t wdm_t;
-	static_assert(sizeof(wdm_t) * 8 >= CNC, "write disable mask needs at least as many bits as max check node links");
+	static_assert(sizeof(wdm_t) * 8 >= TABLE::LINKS_MAX_CN, "write disable mask needs at least as many bits as max check node links");
 	Rotate<TYPE, D> rotate;
 
 	TYPE bnl[BNL];
-	TYPE msg[MSG];
-	TYPE pty[PTY];
+	TYPE var[VAR];
 	Loc loc[LOC];
 	wdm_t wdm[PTY];
-	int16_t csh[MSG];
+	int16_t csh[VAR];
 	uint8_t cnc[q];
 
 	static TYPE eor(TYPE a, TYPE b)
@@ -79,35 +79,22 @@ class LDPCDecoder
 	{
 		Loc *lo = loc;
 		for (int i = 0; i < q; ++i) {
-			int cnt = cnc[i];
-			int deg = cnt + 2;
+			int deg = cnc[i] + 2;
 			auto res = vmask(vzero<TYPE>());
 			for (int j = 0; j < W; ++j) {
 				TYPE cnv = vdup<TYPE>(1);
 				for (int k = 0; k < deg; ++k) {
-					TYPE tmp;
-					if (k < cnt) {
-						int offset = lo[k].off;
-						int shift = -lo[k].shi;
-						shift -= csh[offset];
-						shift %= D;
-						tmp = rotate(msg[offset], shift);
-					} else if (k == cnt) {
-						tmp = pty[W*i+j];
-					} else {
-						if (i) {
-							tmp = pty[W*(i-1)+j];
-						} else if (j) {
-							tmp = pty[W*(q-1)+j-1];
-						} else {
-							tmp = rotate(pty[PTY-1], 1);
-							tmp.v[0] = 127;
-						}
-					}
+					int offset = lo[k].off;
+					int shift = lo[k].shi;
+					shift -= csh[offset];
+					shift %= D;
+					TYPE tmp = rotate(var[offset], shift);
+					if (i == 0 && j == 0 && offset == VAR-1)
+						tmp.v[0] = 127;
 					cnv = vsign(cnv, tmp);
 				}
 				res = vorr(res, vclez(cnv));
-				lo += cnt;
+				lo += deg;
 			}
 			for (int n = 0; n < D; ++n)
 				if (res.v[n])
@@ -121,8 +108,7 @@ class LDPCDecoder
 		Loc *lo = loc;
 		wdm_t *wd = wdm;
 		for (int i = 0; i < q; ++i) {
-			int cnt = cnc[i];
-			int deg = cnt + 2;
+			int deg = cnc[i] + 2;
 			for (int j = 0; j < W; ++j) {
 				TYPE mags[deg], inps[deg];
 				TYPE min0 = vdup<TYPE>(127);
@@ -130,31 +116,23 @@ class LDPCDecoder
 				TYPE signs = vdup<TYPE>(127);
 				bool write_conflict = false;
 				int last_offset = -1;
+				int8_t prev_val = 0;
 
 				for (int k = 0; k < deg; ++k) {
-					TYPE tmp;
-					if (k < cnt) {
-						int offset = lo[k].off;
-						int shift = -lo[k].shi;
-						shift -= csh[offset];
-						shift %= D;
-						tmp = rotate(msg[offset], shift);
-						if (last_offset == offset)
-							write_conflict = true;
-						last_offset = offset;
-					} else if (k == cnt) {
-						tmp = pty[W*i+j];
-					} else {
-						if (i) {
-							tmp = pty[W*(i-1)+j];
-						} else if (j) {
-							tmp = pty[W*(q-1)+j-1];
-						} else {
-							tmp = rotate(pty[PTY-1], 1);
-							tmp.v[0] = 127;
-						}
+					int offset = lo[k].off;
+					int shift = lo[k].shi;
+					shift -= csh[offset];
+					shift %= D;
+					TYPE tmp = rotate(var[offset], shift);
+					if (i == 0 && j == 0 && offset == VAR-1) {
+						prev_val = tmp.v[0];
+						tmp.v[0] = 127;
 					}
 
+					if (last_offset == offset)
+						write_conflict = true;
+					last_offset = offset;
+
 					TYPE inp = vqsub(tmp, bl[k]);
 
 					TYPE mag = vqabs(inp);
@@ -184,34 +162,23 @@ class LDPCDecoder
 
 					TYPE tmp = vqadd(inp, out);
 
-					if (k < cnt) {
-						if (!write_conflict || !((*wd>>k)&1)) {
-							bl[k] = out;
-							int offset = lo[k].off;
-							int shift = -lo[k].shi;
-							msg[offset] = tmp;
-							csh[offset] = shift;
-						}
-					} else if (k == cnt) {
+					int offset = lo[k].off;
+					int shift = lo[k].shi;
+
+					if (i == 0 && j == 0 && offset == VAR-1)
+						tmp.v[0] = prev_val;
+
+					if (!write_conflict || !((*wd>>k)&1)) {
 						bl[k] = out;
-						pty[W*i+j] = tmp;
-					} else {
-						bl[k] = out;
-						if (i) {
-							pty[W*(i-1)+j] = tmp;
-						} else if (j) {
-							pty[W*(q-1)+j-1] = tmp;
-						} else {
-							tmp.v[0] = pty[PTY-1].v[D-1];
-							pty[PTY-1] = rotate(tmp, -1);
-						}
+						var[offset] = tmp;
+						csh[offset] = shift;
 					}
 				}
 				if (write_conflict) {
-					for (int first = 0, c = 1; c < cnt; ++c) {
-						if (lo[first].off != lo[c].off || c == cnt-1) {
-							int last = c - 1;
-							if (c == cnt-1)
+					for (int first = 0, k = 1; k < deg; ++k) {
+						if (lo[first].off != lo[k].off || k == deg-1) {
+							int last = k - 1;
+							if (k == deg-1)
 								++last;
 							if (last != first) {
 								int count = last - first + 1;
@@ -221,12 +188,12 @@ class LDPCDecoder
 								wdm_t ror = (tmp >> 1) | (tmp << (count-1));
 								*wd = (cur & ~mask) | (ror & mask);
 							}
-							first = c;
+							first = k;
 						}
 					}
 					++wd;
 				}
-				lo += cnt;
+				lo += deg;
 				bl += deg;
 			}
 		}
@@ -257,6 +224,7 @@ public:
 		wdm_t *wd = wdm;
 		for (int i = 0; i < q; ++i) {
 			int cnt = cnc[i];
+			int deg = cnt + 2;
 			int offset[cnt], shift[cnt];
 			for (int c = 0; c < cnt; ++c) {
 				shift[c] = pos[CNC*i+c] % M;
@@ -265,17 +233,30 @@ public:
 			for (int j = 0; j < W; ++j) {
 				for (int c = 0; c < cnt; ++c) {
 					lo[c].off = offset[c] / D + shift[c] % W;
-					lo[c].shi = shift[c] / W;
+					lo[c].shi = (D - shift[c] / W) % D;
 					shift[c] = (shift[c] + 1) % M;
 				}
-				std::sort(lo, lo + cnt, [](const Loc &a, const Loc &b){ return a.off < b.off; });
+				if (i) {
+					lo[cnt].off = MSG+W*(i-1)+j;
+					lo[cnt].shi = 0;
+				} else if (j) {
+					lo[cnt].off = MSG+W*(q-1)+j-1;
+					lo[cnt].shi = 0;
+				} else {
+					lo[cnt].off = VAR-1;
+					lo[cnt].shi = 1;
+				}
+				lo[cnt+1].off = MSG+W*i+j;
+				lo[cnt+1].shi = 0;
+
+				std::sort(lo, lo + deg, [](const Loc &a, const Loc &b){ return a.off < b.off; });
 				wdm_t tmp = 0;
-				for (int c = 0; c < cnt-1; ++c)
-					if (lo[c].off == lo[c+1].off)
-						tmp |= 1 << c;
+				for (int d = 0; d < deg-1; ++d)
+					if (lo[d].off == lo[d+1].off)
+						tmp |= 1 << d;
 				if (tmp)
 					*wd++ = tmp;
-				lo += cnt;
+				lo += deg;
 			}
 		}
 		//assert(lo <= loc + LOC);
@@ -285,28 +266,28 @@ public:
 	{
 		for (int i = 0; i < BNL; ++i)
 			bnl[i] = vzero<TYPE>();
-		for (int i = 0; i < MSG; ++i)
+		for (int i = 0; i < VAR; ++i)
 			csh[i] = 0;
 		for (int i = 0; i < K/M; ++i)
 			for (int j = 0; j < W; ++j)
 				for (int n = 0; n < D; ++n)
-					msg[W*i+j].v[n] = message[M*i+W*n+j];
+					var[W*i+j].v[n] = message[M*i+W*n+j];
 		for (int i = 0; i < q; ++i)
 			for (int j = 0; j < W; ++j)
 				for (int n = 0; n < D; ++n)
-					pty[W*i+j].v[n] = parity[q*(W*n+j)+i];
+					var[MSG+W*i+j].v[n] = parity[q*(W*n+j)+i];
 		while (bad() && --trials >= 0)
 			update();
-		for (int i = 0; i < MSG; ++i)
-			msg[i] = rotate(msg[i], -csh[i]);
+		for (int i = 0; i < VAR; ++i)
+			var[i] = rotate(var[i], -csh[i]);
 		for (int i = 0; i < K/M; ++i)
 			for (int j = 0; j < W; ++j)
 				for (int n = 0; n < D; ++n)
-					message[M*i+W*n+j] = msg[W*i+j].v[n];
+					message[M*i+W*n+j] = var[W*i+j].v[n];
 		for (int i = 0; i < q; ++i)
 			for (int j = 0; j < W; ++j)
 				for (int n = 0; n < D; ++n)
-					parity[q*(W*n+j)+i] = pty[W*i+j].v[n];
+					parity[q*(W*n+j)+i] = var[MSG+W*i+j].v[n];
 		return trials;
 	}
 };