From 38c676f5591b53f34eb96eb1772bb6165763263d Mon Sep 17 00:00:00 2001
From: David Monniaux <david.monniaux@univ-grenoble-alpes.fr>
Date: Fri, 29 Mar 2019 06:57:23 +0100
Subject: bitsliced-tea slightly more efficient with ternaries at some places

---
 test/monniaux/bitsliced-tea/bstea.c |  8 ++++----
 test/monniaux/bitsliced-tea/bstea.h | 14 ++++++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

(limited to 'test/monniaux/bitsliced-tea')

diff --git a/test/monniaux/bitsliced-tea/bstea.c b/test/monniaux/bitsliced-tea/bstea.c
index c20c169c..43e29d45 100644
--- a/test/monniaux/bitsliced-tea/bstea.c
+++ b/test/monniaux/bitsliced-tea/bstea.c
@@ -86,7 +86,7 @@ void encrypt(parallel_blocks_t v, const parallel_keys_t k, unsigned int r)
         * in the expansion of multiples of 32/golden-ratio, 
         * or 32/(1+sqrt(5)/2
         */
-       ai = (sum & (1<<i)) ? VECTOR_AT_ONE : VECTOR_AT_ZERO;
+       ai = TERNARY((sum & (1<<i)), VECTOR_AT_ONE, VECTOR_AT_ZERO);
        bi = v[offset_v1 + i];
        aandb = ai & bi;
        axorb = ai ^ bi;
@@ -147,7 +147,7 @@ void encrypt(parallel_blocks_t v, const parallel_keys_t k, unsigned int r)
      carry = 0;
      for (i = 0;i < 32;++i) {
        /* VECTOR_AT_ONE where the ith bit of the sum is set */
-       ai = (sum & (1<<i)) ? VECTOR_AT_ONE : VECTOR_AT_ZERO;
+       ai = TERNARY((sum & (1<<i)), VECTOR_AT_ONE, VECTOR_AT_ZERO);
        bi = v[offset_v0 + i];
        aandb = ai & bi;
        axorb = ai ^ bi;
@@ -261,7 +261,7 @@ void decrypt(parallel_blocks_t v, const parallel_keys_t k, unsigned int r)
      carry = 0;
      for (i = 0;i < 32;++i) {
        /* VECTOR_AT_ONE where the ith bit of the sum is set */
-       ai = (sum & (1<<i)) ? VECTOR_AT_ONE : VECTOR_AT_ZERO;
+       ai = TERNARY((sum & (1<<i)), VECTOR_AT_ONE, VECTOR_AT_ZERO);
        bi = v[offset_v0 + i];
        aandb = ai & bi;
        axorb = ai ^ bi;
@@ -323,7 +323,7 @@ void decrypt(parallel_blocks_t v, const parallel_keys_t k, unsigned int r)
      carry = 0;
      for (i = 0;i < 32;++i) {
        /* VECTOR_AT_ONE where the ith bit of the sum is set */
-       ai = (sum & (1<<i)) ? VECTOR_AT_ONE : VECTOR_AT_ZERO;
+       ai = TERNARY((sum & (1<<i)), VECTOR_AT_ONE, VECTOR_AT_ZERO);
        bi = v[offset_v1 + i];
        aandb = ai & bi;
        axorb = ai ^ bi;
diff --git a/test/monniaux/bitsliced-tea/bstea.h b/test/monniaux/bitsliced-tea/bstea.h
index 305bd403..fa767996 100644
--- a/test/monniaux/bitsliced-tea/bstea.h
+++ b/test/monniaux/bitsliced-tea/bstea.h
@@ -6,6 +6,20 @@
 
 #include "bstea_wordsize.h"
 
+static inline long compcert_ternary_signedl(long x, long v0, long v1) {
+  return ((-(x==0)) & v0) | ((-(x!=0)) & v1);
+}
+
+static inline uint32_t compcert_ternary(uint32_t x, uint32_t v0, uint32_t v1) {
+  return compcert_ternary_signedl(x, v0, v1);
+}
+
+#if defined(__K1C__)
+#define TERNARY(x, v1, v0) compcert_ternary((x), (v0), (v1))
+#else
+#define TERNARY(x, v1, v0) ((x) ? (v1) : (v0))
+#endif
+
 #define TEA_ROUNDS      32
 
 #define TEA_BLOCK_SIZE  64
-- 
cgit