Add sharable clz/clo inline functions and use them for the mips target.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3455 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 104 insertions, 0 deletions

diff --git a/host-utils.h b/host-utils.h
new file mode 100644
index 0000000000..d1e89c2f3a
--- /dev/null
+++ b/host-utils.h
@@ -0,0 +1,104 @@
+/*
+ * Utility compute operations used by translated code.
+ *
+ * Copyright (c) 2007 Thiemo Seufer
+ * Copyright (c) 2007 Jocelyn Mayer
+ *
+ * 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.
+ */
+
+/* Note that some of those functions may end up calling libgcc functions,
+   depending on the host machine. It is up to the target emulation to
+   cope with that. */
+
+/* Binary search for leading zeros.  */
+
+static always_inline int clz32(uint32_t val)
+{
+    int cnt = 0;
+
+    if (!(val & 0xFFFF0000U)) {
+        cnt += 16;
+        val <<= 16;
+    }
+    if (!(val & 0xFF000000U)) {
+        cnt += 8;
+        val <<= 8;
+    }
+    if (!(val & 0xF0000000U)) {
+        cnt += 4;
+        val <<= 4;
+    }
+    if (!(val & 0xC0000000U)) {
+        cnt += 2;
+        val <<= 2;
+    }
+    if (!(val & 0x80000000U)) {
+        cnt++;
+        val <<= 1;
+    }
+    if (!(val & 0x80000000U)) {
+        cnt++;
+    }
+    return cnt;
+}
+
+static always_inline int clo32(uint32_t val)
+{
+    return clz32(~val);
+}
+
+static always_inline int clz64(uint64_t val)
+{
+    int cnt = 0;
+
+    if (!(val & 0xFFFFFFFF00000000ULL)) {
+        cnt += 32;
+        val <<= 32;
+    }
+    if (!(val & 0xFFFF000000000000ULL)) {
+        cnt += 16;
+        val <<= 16;
+    }
+    if (!(val & 0xFF00000000000000ULL)) {
+        cnt += 8;
+        val <<= 8;
+    }
+    if (!(val & 0xF000000000000000ULL)) {
+        cnt += 4;
+        val <<= 4;
+    }
+    if (!(val & 0xC000000000000000ULL)) {
+        cnt += 2;
+        val <<= 2;
+    }
+    if (!(val & 0x8000000000000000ULL)) {
+        cnt++;
+        val <<= 1;
+    }
+    if (!(val & 0x8000000000000000ULL)) {
+        cnt++;
+    }
+    return cnt;
+}
+
+static always_inline int clo64(uint64_t val)
+{
+    return clz64(~val);
+}