Code cleanup: move half float functions to separate header file.

1 files changed, 91 insertions, 0 deletions

diff --git a/intern/cycles/util/util_half.h b/intern/cycles/util/util_half.h
new file mode 100644
index 00000000000..21192024f7f
--- /dev/null
+++ b/intern/cycles/util/util_half.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+#ifndef __UTIL_HALF_H__
+#define __UTIL_HALF_H__
+
+#include "util_types.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Half Floats */
+
+#ifdef __KERNEL_OPENCL__
+
+#define float4_store_half(h, f, scale) vstore_half4(*(f) * (scale), 0, h);
+
+#else
+
+typedef unsigned short half;
+struct half4 { half x, y, z, w; };
+
+#ifdef __KERNEL_CUDA__
+
+ccl_device_inline void float4_store_half(half *h, const float4 *f, float scale)
+{
+	h[0] = __float2half_rn(f->x * scale);
+	h[1] = __float2half_rn(f->y * scale);
+	h[2] = __float2half_rn(f->z * scale);
+	h[3] = __float2half_rn(f->w * scale);
+}
+
+#else
+
+ccl_device_inline void float4_store_half(half *h, const float4 *f, float scale)
+{
+#ifndef __KERNEL_SSE2__
+	for(int i = 0; i < 4; i++) {
+		/* optimized float to half for pixels:
+		 * assumes no negative, no nan, no inf, and sets denormal to 0 */
+		union { uint i; float f; } in;
+		float fscale = (*f)[i] * scale;
+		in.f = (fscale > 0.0f)? ((fscale < 65500.0f)? fscale: 65500.0f): 0.0f;
+		int x = in.i;
+
+		int absolute = x & 0x7FFFFFFF;
+		int Z = absolute + 0xC8000000;
+		int result = (absolute < 0x38800000)? 0: Z;
+		int rshift = (result >> 13);
+
+		h[i] = (rshift & 0x7FFF);
+	}
+#else
+	/* same as above with SSE */
+	const __m128 mm_scale = _mm_set_ps1(scale);
+	const __m128i mm_38800000 = _mm_set1_epi32(0x38800000);
+	const __m128i mm_7FFF = _mm_set1_epi32(0x7FFF);
+	const __m128i mm_7FFFFFFF = _mm_set1_epi32(0x7FFFFFFF);
+	const __m128i mm_C8000000 = _mm_set1_epi32(0xC8000000);
+
+	__m128 mm_fscale = _mm_mul_ps(*(__m128*)f, mm_scale);
+	__m128i x = _mm_castps_si128(_mm_min_ps(_mm_max_ps(mm_fscale, _mm_set_ps1(0.0f)), _mm_set_ps1(65500.0f)));
+	__m128i absolute = _mm_and_si128(x, mm_7FFFFFFF);
+	__m128i Z = _mm_add_epi32(absolute, mm_C8000000);
+	__m128i result = _mm_andnot_si128(_mm_cmplt_epi32(absolute, mm_38800000), Z); 
+	__m128i rh = _mm_and_si128(_mm_srai_epi32(result, 13), mm_7FFF);
+
+	_mm_storel_pi((__m64*)h, _mm_castsi128_ps(_mm_packs_epi32(rh, rh)));
+#endif
+}
+
+#endif
+
+#endif
+
+CCL_NAMESPACE_END
+
+#endif /* __UTIL_HALF_H__ */
+