1 files changed, 57 insertions, 0 deletions
diff --git a/generic/lib/math/ilogb.cl b/generic/lib/math/ilogb.cl
new file mode 100644
index 0000000..b783b7e
--- /dev/null
+++ b/generic/lib/math/ilogb.cl
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2015 Advanced Micro Devices, Inc.
+ * Copyright (c) 2016 Aaron Watry
+ *
+ * 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 <clc/clc.h>
+#include "../clcmacro.h"
+#include "math.h"
+
+_CLC_OVERLOAD _CLC_DEF int ilogb(float x) {
+    uint ux = as_uint(x);
+    uint ax = ux & EXSIGNBIT_SP32;
+    int rs = -118 - (int) clz(ux & MANTBITS_SP32);
+    int r = (int) (ax >> EXPSHIFTBITS_SP32) - EXPBIAS_SP32;
+    r = ax < 0x00800000U ? rs : r;
+    r = ax > EXPBITS_SP32 | ax == 0 ? 0x80000000 : r;
+    r = ax == EXPBITS_SP32 ? 0x7fffffff : r;
+    return r;
+}
+
+_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, int, ilogb, float);
+
+#ifdef cl_khr_fp64
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+_CLC_OVERLOAD _CLC_DEF ilogb(double x) {
+    ulong ux = as_ulong(x);
+    ulong ax = ux & ~SIGNBIT_DP64;
+    int r = (int) (ax >> EXPSHIFTBITS_DP64) - EXPBIAS_DP64;
+    int rs = -1011 - (int) clz(ax & MANTBITS_DP64);
+    r = ax < 0x0010000000000000UL ? rs : r;
+    r = ax > 0x7ff0000000000000UL | ax == 0UL ? 0x80000000 : r;
+    r = ax == 0x7ff0000000000000UL ? 0x7fffffff : r;
+    return r;
+}
+
+_CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, int, ilogb, double);
+
+#endif // cl_khr_fp64