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Diffstat (limited to 'contrib/bearssl/src/int/i15_iszero.c')
-rw-r--r--contrib/bearssl/src/int/i15_iszero.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/contrib/bearssl/src/int/i15_iszero.c b/contrib/bearssl/src/int/i15_iszero.c
new file mode 100644
index 000000000000..d4b6f10b2ac0
--- /dev/null
+++ b/contrib/bearssl/src/int/i15_iszero.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/* see inner.h */
+uint32_t
+br_i15_iszero(const uint16_t *x)
+{
+ uint32_t z;
+ size_t u;
+
+ z = 0;
+ for (u = (x[0] + 15) >> 4; u > 0; u --) {
+ z |= x[u];
+ }
+ return ~(z | -z) >> 31;
+}