Remove dead stores.

Found by the Clang static analyzer.

diff --git a/src/ed25519/sc.c b/src/ed25519/sc.c
index 42cfc2d..3364de4 100644 (file)
--- a/src/ed25519/sc.c
+++ b/src/ed25519/sc.c
@@ -81,42 +81,36 @@ void sc_reduce(unsigned char *s) {
     s14 -= s23 * 997805;
     s15 += s23 * 136657;
     s16 -= s23 * 683901;
-    s23 = 0;
     s10 += s22 * 666643;
     s11 += s22 * 470296;
     s12 += s22 * 654183;
     s13 -= s22 * 997805;
     s14 += s22 * 136657;
     s15 -= s22 * 683901;
-    s22 = 0;
     s9 += s21 * 666643;
     s10 += s21 * 470296;
     s11 += s21 * 654183;
     s12 -= s21 * 997805;
     s13 += s21 * 136657;
     s14 -= s21 * 683901;
-    s21 = 0;
     s8 += s20 * 666643;
     s9 += s20 * 470296;
     s10 += s20 * 654183;
     s11 -= s20 * 997805;
     s12 += s20 * 136657;
     s13 -= s20 * 683901;
-    s20 = 0;
     s7 += s19 * 666643;
     s8 += s19 * 470296;
     s9 += s19 * 654183;
     s10 -= s19 * 997805;
     s11 += s19 * 136657;
     s12 -= s19 * 683901;
-    s19 = 0;
     s6 += s18 * 666643;
     s7 += s18 * 470296;
     s8 += s18 * 654183;
     s9 -= s18 * 997805;
     s10 += s18 * 136657;
     s11 -= s18 * 683901;
-    s18 = 0;
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
     s6 -= shl64(carry6, 21);
@@ -156,35 +150,30 @@ void sc_reduce(unsigned char *s) {
     s8 -= s17 * 997805;
     s9 += s17 * 136657;
     s10 -= s17 * 683901;
-    s17 = 0;
     s4 += s16 * 666643;
     s5 += s16 * 470296;
     s6 += s16 * 654183;
     s7 -= s16 * 997805;
     s8 += s16 * 136657;
     s9 -= s16 * 683901;
-    s16 = 0;
     s3 += s15 * 666643;
     s4 += s15 * 470296;
     s5 += s15 * 654183;
     s6 -= s15 * 997805;
     s7 += s15 * 136657;
     s8 -= s15 * 683901;
-    s15 = 0;
     s2 += s14 * 666643;
     s3 += s14 * 470296;
     s4 += s14 * 654183;
     s5 -= s14 * 997805;
     s6 += s14 * 136657;
     s7 -= s14 * 683901;
-    s14 = 0;
     s1 += s13 * 666643;
     s2 += s13 * 470296;
     s3 += s13 * 654183;
     s4 -= s13 * 997805;
     s5 += s13 * 136657;
     s6 -= s13 * 683901;
-    s13 = 0;
     s0 += s12 * 666643;
     s1 += s12 * 470296;
     s2 += s12 * 654183;
@@ -277,7 +266,6 @@ void sc_reduce(unsigned char *s) {
     s3 -= s12 * 997805;
     s4 += s12 * 136657;
     s5 -= s12 * 683901;
-    s12 = 0;
     carry0 = s0 >> 21;
     s1 += carry0;
     s0 -= shl64(carry0, 21);
@@ -543,42 +531,36 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s14 -= s23 * 997805;
     s15 += s23 * 136657;
     s16 -= s23 * 683901;
-    s23 = 0;
     s10 += s22 * 666643;
     s11 += s22 * 470296;
     s12 += s22 * 654183;
     s13 -= s22 * 997805;
     s14 += s22 * 136657;
     s15 -= s22 * 683901;
-    s22 = 0;
     s9 += s21 * 666643;
     s10 += s21 * 470296;
     s11 += s21 * 654183;
     s12 -= s21 * 997805;
     s13 += s21 * 136657;
     s14 -= s21 * 683901;
-    s21 = 0;
     s8 += s20 * 666643;
     s9 += s20 * 470296;
     s10 += s20 * 654183;
     s11 -= s20 * 997805;
     s12 += s20 * 136657;
     s13 -= s20 * 683901;
-    s20 = 0;
     s7 += s19 * 666643;
     s8 += s19 * 470296;
     s9 += s19 * 654183;
     s10 -= s19 * 997805;
     s11 += s19 * 136657;
     s12 -= s19 * 683901;
-    s19 = 0;
     s6 += s18 * 666643;
     s7 += s18 * 470296;
     s8 += s18 * 654183;
     s9 -= s18 * 997805;
     s10 += s18 * 136657;
     s11 -= s18 * 683901;
-    s18 = 0;
     carry6 = (s6 + (1 << 20)) >> 21;
     s7 += carry6;
     s6 -= shl64(carry6, 21);
@@ -618,35 +600,30 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s8 -= s17 * 997805;
     s9 += s17 * 136657;
     s10 -= s17 * 683901;
-    s17 = 0;
     s4 += s16 * 666643;
     s5 += s16 * 470296;
     s6 += s16 * 654183;
     s7 -= s16 * 997805;
     s8 += s16 * 136657;
     s9 -= s16 * 683901;
-    s16 = 0;
     s3 += s15 * 666643;
     s4 += s15 * 470296;
     s5 += s15 * 654183;
     s6 -= s15 * 997805;
     s7 += s15 * 136657;
     s8 -= s15 * 683901;
-    s15 = 0;
     s2 += s14 * 666643;
     s3 += s14 * 470296;
     s4 += s14 * 654183;
     s5 -= s14 * 997805;
     s6 += s14 * 136657;
     s7 -= s14 * 683901;
-    s14 = 0;
     s1 += s13 * 666643;
     s2 += s13 * 470296;
     s3 += s13 * 654183;
     s4 -= s13 * 997805;
     s5 += s13 * 136657;
     s6 -= s13 * 683901;
-    s13 = 0;
     s0 += s12 * 666643;
     s1 += s12 * 470296;
     s2 += s12 * 654183;
@@ -739,7 +716,6 @@ void sc_muladd(unsigned char *s, const unsigned char *a, const unsigned char *b,
     s3 -= s12 * 997805;
     s4 += s12 * 136657;
     s5 -= s12 * 683901;
-    s12 = 0;
     carry0 = s0 >> 21;
     s1 += carry0;
     s0 -= shl64(carry0, 21);