diff --git a/Makefile.in b/Makefile.in
index dc37fac..b1fb133 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1,8 +1,9 @@
 
 CC= @CC@
-CSTD= -std=c99 -Wall -D_POSIX_C_SOURCE=200112L -no-pie
+CSTD= -std=c99 -Wall -D_POSIX_C_SOURCE=200112L
 CFLAGS= $(CSTD) @CFLAGS@ -DED25519_@ED25519IMPL@ @FILTERDEF@
-ASFLAGS= -no-pie
+ASFLAGS=
+LDFLAGS= -no-pie
 MV= mv
 
 ED25519_ref10= $(patsubst %.c,%.c.o,$(wildcard ed25519/ref10/*.c))
@@ -58,16 +59,16 @@ default: mkp224o
 all: $(EXE)
 
 mkp224o: $(MAINOBJ)
-	$(CC) $(CFLAGS) -o $@.tmp $^ $(MAINLIB) && $(MV) $@.tmp $@
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@.tmp $^ $(MAINLIB) && $(MV) $@.tmp $@
 
 test_base32: $(TEST_BASE32OBJ)
-	$(CC) $(CFLAGS) -o $@.tmp $^ && $(MV) $@.tmp $@
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@.tmp $^ && $(MV) $@.tmp $@
 
 test_base16: $(TEST_BASE16OBJ)
-	$(CC) $(CFLAGS) -o $@.tmp $^ && $(MV) $@.tmp $@
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@.tmp $^ && $(MV) $@.tmp $@
 
 test_ed25519: $(TEST_ED25519OBJ)
-	$(CC) $(CFLAGS) -o $@.tmp $^ $(TEST_ED25519LIB) && $(MV) $@.tmp $@
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@.tmp $^ $(TEST_ED25519LIB) && $(MV) $@.tmp $@
 
 %.c.o: %.c
 	$(CC) $(CFLAGS) -c -o $@.tmp $< && $(MV) $@.tmp $@
@@ -349,12 +350,12 @@ ed25519/ref10/sign.c.o: ed25519/amd64-51-30k/crypto_hash_sha512.h
 ed25519/ref10/sign.c.o: ed25519/ref10/ge.h ed25519/ref10/fe.h
 ed25519/ref10/sign.c.o: ed25519/ref10/crypto_int32.h ed25519/ref10/sc.h
 keccak.c.o: types.h keccak.h
-main.c.o: ed25519/ed25519.h ed25519/ref10/ed25519.h ed25519/ref10/ge.h
-main.c.o: ed25519/ref10/fe.h ed25519/ref10/crypto_int32.h
-main.c.o: ed25519/amd64-51-30k/ed25519.h ed25519/amd64-51-30k/ge25519.h
-main.c.o: ed25519/amd64-51-30k/fe25519.h ed25519/amd64-51-30k/sc25519.h
-main.c.o: ed25519/amd64-64-24k/ed25519.h ed25519/amd64-64-24k/ge25519.h
-main.c.o: types.h vec.h base32.h keccak.h
+main.c.o: types.h likely.h vec.h base32.h ed25519/ed25519.h
+main.c.o: ed25519/ref10/ed25519.h ed25519/ref10/ge.h ed25519/ref10/fe.h
+main.c.o: ed25519/ref10/crypto_int32.h ed25519/amd64-51-30k/ed25519.h
+main.c.o: ed25519/amd64-51-30k/ge25519.h ed25519/amd64-51-30k/fe25519.h
+main.c.o: ed25519/amd64-51-30k/sc25519.h ed25519/amd64-64-24k/ed25519.h
+main.c.o: ed25519/amd64-64-24k/ge25519.h keccak.h
 test_base16.c.o: types.h base16.h
 test_base32.c.o: types.h base32.h
 test_ed25519.c.o: types.h base16.h ed25519/ed25519.h ed25519/ref10/ed25519.h
diff --git a/likely.h b/likely.h
new file mode 100644
index 0000000..51c7998
--- /dev/null
+++ b/likely.h
@@ -0,0 +1,7 @@
+#ifdef __GNUC__
+#define likely(x)   __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+#else
+#define likely(x)   (x)
+#define unlikely(x) (x)
+#endif
diff --git a/main.c b/main.c
index b669157..8f5f641 100644
--- a/main.c
+++ b/main.c
@@ -6,14 +6,14 @@
 #include <time.h>
 #include <pthread.h>
 #include <signal.h>
-#include <sodium/randombytes.h>
-#include "ed25519/ed25519.h"
-
 #include <sys/stat.h>
+#include <sodium/randombytes.h>
 
 #include "types.h"
+#include "likely.h"
 #include "vec.h"
 #include "base32.h"
+#include "ed25519/ed25519.h"
 #include "keccak.h"
 
 // additional leading zero is added by C
@@ -310,13 +310,13 @@ initseed:
 	randombytes(seed,sizeof(seed));
 
 again:
-	if (endwork)
+	if (unlikely(endwork))
 		goto end;
 
 	ed25519_seckey_expand(sk,seed);
 	ed25519_pubkey(pk,sk);
 	FILTERFOR(i) {
-		if (MATCHFILTER(i,pk)) {
+		if (unlikely(MATCHFILTER(i,pk))) {
 			memcpy(&hashsrc[checksumstrlen], &pubonion[pkprefixlen], PUBLIC_LEN);
 			FIPS202_SHA3_256(hashsrc, sizeof(hashsrc), &pubonion[pkprefixlen + PUBLIC_LEN]);
 			pubonion[pkprefixlen + PUBLIC_LEN + 2] = 0x03; // version
@@ -379,11 +379,11 @@ initseed:
 	for (counter = 0;counter < U64_MAX-8;counter += 8) {
 		ge_p1p1 sum;
 		
-		if (endwork)
+		if (unlikely(endwork))
 			goto end;
 		
 		FILTERFOR(i) {
-			if (MATCHFILTER(i,pk)) {
+			if (unlikely(MATCHFILTER(i,pk))) {
 				// found!
 				// update secret key with counter
 				addu64toscalar32(sk,counter);
diff --git a/test_ed25519.c b/test_ed25519.c
index 197486c..78c11bc 100644
--- a/test_ed25519.c
+++ b/test_ed25519.c
@@ -48,13 +48,13 @@ int main()
 		base16_from(seedbuf, &mask, test0[i].seed);
 		base16_from(secretbuf1, &mask, test0[i].secret);
 		base16_from(publicbuf1, &mask, test0[i].public);
-		ed25519_ref10_seckey_expand(secretbuf2, seedbuf);
+		ed25519_seckey_expand(secretbuf2, seedbuf);
 		WARNF(memcmp(secretbuf1, secretbuf2, SECRETKEYBYTES) == 0) {
 			base16_to(str1, secretbuf1, sizeof(secretbuf1));
 			base16_to(str2, secretbuf2, sizeof(secretbuf2));
 			fprintf(stderr, "expected: %s got %s\n", str1, str2);
 		}
-		ed25519_ref10_pubkey(publicbuf2, secretbuf1);
+		ed25519_pubkey(publicbuf2, secretbuf1);
 		WARNF(memcmp(publicbuf1, publicbuf2, PUBLICKEYBYTES) == 0) {
 			base16_to(str1, publicbuf1, sizeof(publicbuf1));
 			base16_to(str2, publicbuf2, sizeof(publicbuf2));