1 files changed, 51 insertions, 0 deletions
diff --git a/zap/source/amd64/mem/utf8dec.c b/zap/source/amd64/mem/utf8dec.c
new file mode 100644
index 0000000..62f3f61
--- /dev/null
+++ b/zap/source/amd64/mem/utf8dec.c
@@ -0,0 +1,51 @@
+/*
+ Copyright 2022 Gabriel Jensen.
+ This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+ If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
+*/
+
+#include <zap/priv.h>
+
+#include <zap/mem.h>
+
+void zap_utf8dec(zap_chr8 const * const _in,zap_chr20 * const _out) {
+ zap_chr8 const * in = _in;
+ zap_chr20 * out = _out;
+ for (;;++out) {
+ zap_chr8 const oct = *in;
+ if (oct >= 0xF0u) { /* Four octets. */
+ zap_chr20 chr = ((zap_chr20)oct ^ 0xF0u) << 0x12u;
+ ++in;
+ chr += ((zap_chr20)*in ^ 0x80u) << 0xCu;
+ ++in;
+ chr += ((zap_chr20)*in ^ 0x80u) << 0x6u;
+ ++in;
+ chr += (zap_chr20)*in ^ 0x80u;
+ ++in;
+ *out = chr;
+ continue;
+ }
+ if (oct >= 0xE0u) { /* Three octets. */
+ zap_chr20 chr = ((zap_chr20)oct ^ 0xE0u) << 0xCu;
+ ++in;
+ chr += ((zap_chr20)*in ^ 0x80u) << 0x6u;
+ ++in;
+ chr += (zap_chr20)*in ^ 0x80u;
+ ++in;
+ *out = chr;
+ continue;
+ }
+ if (oct >= 0xC0u) { /* Two octets. */
+ zap_chr20 chr = ((zap_chr20)oct ^ 0xC0u) << 0x6u;
+ ++in;
+ chr += (zap_chr20)*in ^ 0x80u;
+ ++in;
+ *out = chr;
+ continue;
+ }
+ /* One octet. */
+ *out = oct;
+ ++in;
+ if (oct == 0x0u) {break;}
+ }
+}