[Libclc-dev] [PATCH] math: Add ilogb ported from amd-builtins

[Aaron Watry via Libclc-dev]

The scalar float/double function bodies are a direct copy/paste
with usage of the CLC wrappers to vectorize them.

Signed-off-by: Aaron Watry <awatry at gmail.com>
---
These have been tested using the tests I just sent to the piglit list.

Those tests only handle float, and ignore the ilogb(0) and ilogb(nan) cases due to
the fact that ilogb(0||nan) can return either MAX_INT or MIN_INT depending on the
implementation's desires.

If you want more input values tested, and have good candidates, let me know. Otherwise, I
wouldn't turn down a run through the CTS if someone has a few minutes (since I don't have access).

 generic/include/clc/clc.h          |  1 +
 generic/include/clc/math/ilogb.h   |  5 ++++
 generic/include/clc/math/ilogb.inc |  1 +
 generic/lib/SOURCES                |  1 +
 generic/lib/math/ilogb.cl          | 57 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 65 insertions(+)
 create mode 100644 generic/include/clc/math/ilogb.h
 create mode 100644 generic/include/clc/math/ilogb.inc
 create mode 100644 generic/lib/math/ilogb.cl

diff --git a/generic/include/clc/clc.h b/generic/include/clc/clc.h
index 4060ea1..b106923 100644
--- a/generic/include/clc/clc.h
+++ b/generic/include/clc/clc.h
@@ -62,6 +62,7 @@
 #include <clc/math/half_rsqrt.h>
 #include <clc/math/half_sqrt.h>
 #include <clc/math/hypot.h>
+#include <clc/math/ilogb.h>
 #include <clc/math/ldexp.h>
 #include <clc/math/log.h>
 #include <clc/math/log10.h>
diff --git a/generic/include/clc/math/ilogb.h b/generic/include/clc/math/ilogb.h
new file mode 100644
index 0000000..2bb9e9c
--- /dev/null
+++ b/generic/include/clc/math/ilogb.h
@@ -0,0 +1,5 @@
+#define __CLC_BODY <clc/math/ilogb.inc>
+
+#include <clc/math/gentype.inc>
+
+#undef __CLC_BODY
diff --git a/generic/include/clc/math/ilogb.inc b/generic/include/clc/math/ilogb.inc
new file mode 100644
index 0000000..7f99fb4
--- /dev/null
+++ b/generic/include/clc/math/ilogb.inc
@@ -0,0 +1 @@
+_CLC_OVERLOAD _CLC_DECL __CLC_INTN ilogb(__CLC_GENTYPE x);
diff --git a/generic/lib/SOURCES b/generic/lib/SOURCES
index c3a5a8a..facb58b 100644
--- a/generic/lib/SOURCES
+++ b/generic/lib/SOURCES
@@ -90,6 +90,7 @@ math/frexp.cl
 math/half_rsqrt.cl
 math/half_sqrt.cl
 math/hypot.cl
+math/ilogb.cl
 math/clc_ldexp.cl
 math/ldexp.cl
 math/log.cl
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
-- 
2.5.0