math: Add ldexp implementation

Signed-off-by: Aaron Watry <awatry@gmail.com>

Tom Stellard:
  - Add denormal handling.
  - Share vectorization code with r600 implementation.

Patch By: Aaron Watry

llvm-svn: 236639

4 files changed, 172 insertions, 0 deletions

diff --git a/libclc/generic/lib/SOURCES b/libclc/generic/lib/SOURCES
index d21d6aa2e7e..8eca7624ffd 100644
--- a/libclc/generic/lib/SOURCES
+++ b/libclc/generic/lib/SOURCES
@@ -84,6 +84,7 @@ math/fmod.cl
 math/fract.cl
 math/half_sqrt.cl
 math/hypot.cl
+math/ldexp.cl
 math/log10.cl
 math/log1p.cl
 math/mad.cl
diff --git a/libclc/generic/lib/clcmacro.h b/libclc/generic/lib/clcmacro.h
index 346adf22e84..9ef337b89e4 100644
--- a/libclc/generic/lib/clcmacro.h
+++ b/libclc/generic/lib/clcmacro.h
@@ -115,6 +115,10 @@ _CLC_DEF _CLC_OVERLOAD RET_TYPE FUNCTION(ARG1_TYPE x, ARG2_TYPE y) { \
 } \
 _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, RET_TYPE, FUNCTION, ARG1_TYPE, ARG2_TYPE)
 
+#define _CLC_DEFINE_BINARY_BUILTIN_WITH_SCALAR_SECOND_ARG(RET_TYPE, FUNCTION, BUILTIN, ARG1_TYPE, ARG2_TYPE) \
+_CLC_DEFINE_BINARY_BUILTIN(RET_TYPE, FUNCTION, BUILTIN, ARG1_TYPE, ARG2_TYPE) \
+_CLC_BINARY_VECTORIZE_SCALAR_SECOND_ARG(_CLC_OVERLOAD _CLC_DEF, RET_TYPE, FUNCTION, ARG1_TYPE, ARG2_TYPE)
+
 #define _CLC_DEFINE_UNARY_BUILTIN(RET_TYPE, FUNCTION, BUILTIN, ARG1_TYPE) \
 _CLC_DEF _CLC_OVERLOAD RET_TYPE FUNCTION(ARG1_TYPE x) { \
   return BUILTIN(x); \
diff --git a/libclc/generic/lib/math/ldexp.cl b/libclc/generic/lib/math/ldexp.cl
new file mode 100644
index 00000000000..1802bf32b41
--- /dev/null
+++ b/libclc/generic/lib/math/ldexp.cl
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2014 Advanced Micro Devices, Inc.
+ *
+ * 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 "config.h"
+#include "../clcmacro.h"
+#include "math.h"
+
+_CLC_DEF _CLC_OVERLOAD float ldexp(float x, int n) {
+
+	if (!__clc_fp32_subnormals_supported()) {
+
+		// This treats subnormals as zeros
+		int i = as_int(x);
+		int e = (i >> 23) & 0xff;
+		int m = i & 0x007fffff;
+		int s = i & 0x80000000;
+		int v = add_sat(e, n);
+		v = clamp(v, 0, 0xff);
+		int mr = e == 0 | v == 0 | v == 0xff ? 0 : m;
+		int c = e == 0xff;
+		mr = c ? m : mr;
+		int er = c ? e : v;
+		er = e ? er : e;
+		return as_float( s | (er << 23) | mr );
+	}
+
+	/* supports denormal values */
+	const int multiplier = 24;
+	float val_f;
+	uint val_ui;
+	uint sign;
+	int exponent;
+	val_ui = as_uint(x);
+	sign = val_ui & 0x80000000;
+	val_ui = val_ui & 0x7fffffff;/* remove the sign bit */
+	int val_x = val_ui;
+
+	exponent = val_ui >> 23; /* get the exponent */
+	int dexp = exponent;
+
+	/* denormal support */
+	int fbh = 127 - (as_uint((float)(as_float(val_ui | 0x3f800000) - 1.0f)) >> 23);
+	int dexponent = 25 - fbh;
+	uint dval_ui = (( (val_ui << fbh) & 0x007fffff) | (dexponent << 23));
+	int ex = dexponent + n - multiplier;
+	dexponent = ex;
+	uint val = sign | (ex << 23) | (dval_ui & 0x007fffff);
+	int ex1 = dexponent + multiplier;
+	ex1 = -ex1 +25;
+	dval_ui = (((dval_ui & 0x007fffff )| 0x800000) >> ex1);
+	dval_ui = dexponent > 0 ? val :dval_ui;
+	dval_ui = dexponent > 254 ? 0x7f800000 :dval_ui;  /*overflow*/
+	dval_ui = dexponent < -multiplier ? 0 : dval_ui;  /*underflow*/
+	dval_ui = dval_ui | sign;
+	val_f = as_float(dval_ui);
+
+	exponent += n;
+
+	val = sign | (exponent << 23) | (val_ui & 0x007fffff);
+	ex1 = exponent + multiplier;
+	ex1 = -ex1 +25;
+	val_ui = (((val_ui & 0x007fffff )| 0x800000) >> ex1);
+	val_ui = exponent > 0 ? val :val_ui;
+	val_ui = exponent > 254 ? 0x7f800000 :val_ui;  /*overflow*/
+	val_ui = exponent < -multiplier ? 0 : val_ui;  /*underflow*/
+	val_ui = val_ui | sign;
+
+	val_ui = dexp == 0? dval_ui : val_ui;
+	val_f = as_float(val_ui);
+
+	val_f = isnan(x) | isinf(x) | val_x == 0 ? x : val_f;
+	return val_f;
+}
+
+// This defines all the ldexp(floatN, intN) variants.
+_CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, float, ldexp, float, int)
+
+#ifdef cl_khr_fp64
+
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+_CLC_DEF _CLC_OVERLOAD double ldexp(double x, int n) {
+	long l = as_ulong(x);
+	int e = (l >> 52) & 0x7ff;
+	long s = l & 0x8000000000000000;
+
+	ulong ux = as_ulong(x * 0x1.0p+53);
+	int de = ((int)(ux >> 52) & 0x7ff) - 53;
+	int c = e == 0;
+	e = c ? de: e;
+
+	ux = c ? ux : l;
+
+	int v = e + n;
+	v = clamp(v, -0x7ff, 0x7ff);
+
+	ux &= ~EXPBITS_DP64;
+
+	double mr = as_double(ux | ((ulong)(v+53) << 52));
+	mr = mr * 0x1.0p-53;
+
+	mr = v > 0  ? as_double(ux | ((ulong)v << 52)) : mr;
+
+	mr = v == 0x7ff ? as_double(s | PINFBITPATT_DP64)  : mr;
+	mr = v < -53 ? as_double(s) : mr;
+
+	mr  = ((n == 0) | isinf(x) | (x == 0) ) ? x : mr;
+	return mr;
+}
+
+// This defines all the ldexp(doubleN, intN) variants.
+_CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, ldexp, double, int)
+
+#endif
+
+// This defines all the ldexp(GENTYPE, int) variants
+#define __CLC_BODY <ldexp.inc>
+#include <clc/math/gentype.inc>
diff --git a/libclc/generic/lib/math/ldexp.inc b/libclc/generic/lib/math/ldexp.inc
new file mode 100644
index 00000000000..6e28fbb94ca
--- /dev/null
+++ b/libclc/generic/lib/math/ldexp.inc
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2014 Advanced Micro Devices, Inc.
+ *
+ * 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.
+ */
+
+#ifndef __CLC_SCALAR
+
+_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE ldexp(__CLC_GENTYPE x, int n) {
+  return ldexp(x, (__CLC_INTN)n);
+}
+
+#endif