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authorMattias Andrée <m@maandree.se>2026-05-07 21:13:34 +0200
committerMattias Andrée <m@maandree.se>2026-05-07 21:13:34 +0200
commitaf75e701c43fc4e754f516c81190b77fa4006bb8 (patch)
treee5f073eb2d3c0f60512d5116aaa15b6b64c131f2 /util/libkeccak_behex_upper.c
parentbenchmark.c: fix minor bug (diff)
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Optimise conversion to hexadecimalHEADmaster
Signed-off-by: Mattias Andrée <m@maandree.se>
Diffstat (limited to 'util/libkeccak_behex_upper.c')
-rw-r--r--util/libkeccak_behex_upper.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/util/libkeccak_behex_upper.c b/util/libkeccak_behex_upper.c
index 5186a28..c5f9691 100644
--- a/util/libkeccak_behex_upper.c
+++ b/util/libkeccak_behex_upper.c
@@ -12,11 +12,22 @@
void
libkeccak_behex_upper(char *restrict output, const void *restrict hashsum_, size_t n)
{
+#define S(X)\
+ X"0", X"1", X"2", X"3", X"4", X"5", X"6", X"7",\
+ X"8", X"9", X"A", X"B", X"C", X"D", X"E", X"F"
+#if defined(__GNUC__)
+ __attribute__((__nonstring__))
+#endif
+ static const char lut[256][2] = {
+ S("0"), S("1"), S("2"), S("3"), S("4"), S("5"), S("6"), S("7"),
+ S("8"), S("9"), S("A"), S("B"), S("C"), S("D"), S("E"), S("F")
+ };
+
const unsigned char *restrict hashsum = hashsum_;
output[2 * n] = '\0';
while (n--) {
- output[2 * n + 0] = "0123456789ABCDEF"[(hashsum[n] >> 4) & 15];
- output[2 * n + 1] = "0123456789ABCDEF"[(hashsum[n] >> 0) & 15];
+ output[2 * n + 0] = lut[hashsum[n]][0];
+ output[2 * n + 1] = lut[hashsum[n]][1];
}
}