Initial drop

Add some riscv code

Signed-off-by: Carlos Maiolino <[email protected]>

1 files changed, 63 insertions, 0 deletions

diff --git a/riscv/riscv-probe/libfemto/include/stdbits.h b/riscv/riscv-probe/libfemto/include/stdbits.h
new file mode 100644
index 0000000..2985381
--- /dev/null
+++ b/riscv/riscv-probe/libfemto/include/stdbits.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+#define clz(val) ({                         \
+    int result;                             \
+    switch(sizeof(val)) {                   \
+    case 1: result = clz8(val); break;      \
+    case 2: result = clz16(val); break;     \
+    case 4: result = clz32(val); break;     \
+    case 8: result = clz64(val); break;     \
+    }                                       \
+    result;                                 \
+})
+
+#define ctz(val) ({                         \
+    int result;                             \
+    switch(sizeof(val)) {                   \
+    case 1: result = ctz8(val); break;      \
+    case 2: result = ctz16(val); break;     \
+    case 4: result = ctz32(val); break;     \
+    case 8: result = ctz64(val); break;     \
+    }                                       \
+    result;                                 \
+})
+
+int clz8(int8_t val);
+int clz16(int16_t val);
+int clz32(int32_t val);
+int clz64(int64_t val);
+
+int ctz8(int8_t val);
+int ctz16(int16_t val);
+int ctz32(int32_t val);
+int ctz64(int64_t val);
+
+static inline int ispow2(uintptr_t val)
+{
+    return val && !(val & (val-1));
+}
+
+static inline uintptr_t roundpow2(uintptr_t val)
+{
+    val--;
+    val |= val >> 1;
+    val |= val >> 2;
+    val |= val >> 4;
+    val |= val >> 8;
+    val |= val >> 16;
+#if __SIZE_WIDTH__ == 64
+    val |= val >> 32;
+#endif
+    val++;
+    return val;
+}
+
+#ifdef __cplusplus
+}
+#endif