[Mesa-dev] [PATCH] gallivm: move code for dealing with rgb9e5 and r11g11b10 formats to own file
sroland at vmware.com
sroland at vmware.com
Sat Mar 23 18:09:53 PDT 2013
From: Roland Scheidegger <sroland at vmware.com>
This is really not generic conversion stuff and the code very particular to
these formats.
---
src/gallium/auxiliary/Makefile.sources | 1 +
src/gallium/auxiliary/gallivm/lp_bld_conv.c | 329 -----------------
src/gallium/auxiliary/gallivm/lp_bld_conv.h | 14 -
src/gallium/auxiliary/gallivm/lp_bld_format.h | 18 +
.../auxiliary/gallivm/lp_bld_format_float.c | 373 ++++++++++++++++++++
5 files changed, 392 insertions(+), 343 deletions(-)
create mode 100644 src/gallium/auxiliary/gallivm/lp_bld_format_float.c
diff --git a/src/gallium/auxiliary/Makefile.sources b/src/gallium/auxiliary/Makefile.sources
index 74c7902..898abe0 100644
--- a/src/gallium/auxiliary/Makefile.sources
+++ b/src/gallium/auxiliary/Makefile.sources
@@ -164,6 +164,7 @@ GALLIVM_SOURCES := \
gallivm/lp_bld_flow.c \
gallivm/lp_bld_format_aos.c \
gallivm/lp_bld_format_aos_array.c \
+ gallivm/lp_bld_format_float.c \
gallivm/lp_bld_format_soa.c \
gallivm/lp_bld_format_yuv.c \
gallivm/lp_bld_gather.c \
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_conv.c b/src/gallium/auxiliary/gallivm/lp_bld_conv.c
index 2f39abc..dc3649d 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_conv.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_conv.c
@@ -155,335 +155,6 @@ lp_build_bswap_vec(struct gallivm_state *gallivm,
/**
- * Convert float32 to a float-like value with less exponent and mantissa
- * bits. The mantissa is still biased, and the mantissa still has an implied 1,
- * but there's no sign bit.
- *
- * @param src (vector) float value to convert
- * @param mantissa_bits the number of mantissa bits
- * @param exponent_bits the number of exponent bits
- *
- * Unlike float_to_half using accurate method here.
- * This implements round-towards-zero (trunc) hence too large numbers get
- * converted to largest representable number, not infinity.
- * Small numbers may get converted to denorms, depending on normal
- * float denorm handling of the cpu.
- * Note that compared to the references, below, we skip any rounding bias
- * since we do rounding towards zero - OpenGL allows rounding towards zero
- * (though not preferred) and DX10 even seems to require it.
- * Note that this will not do any packing - the value will
- * look like a "rescaled float" (except for Inf/NaN) but be returned
- * as int32.
- *
- * ref http://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/
- * ref https://gist.github.com/rygorous/2156668
- */
-static LLVMValueRef
-lp_build_float_to_smallfloat_nosign(struct gallivm_state *gallivm,
- struct lp_type i32_type,
- LLVMValueRef src,
- unsigned mantissa_bits,
- unsigned exponent_bits)
-{
- LLVMBuilderRef builder = gallivm->builder;
- LLVMValueRef i32_floatexpmask, i32_smallexpmask, magic, normal;
- LLVMValueRef clamped, tmp, i32_roundmask, small_max, src_abs;
- LLVMValueRef is_nan, is_posinf, is_nan_or_posinf, i32_qnanbit, nan_or_posinf;
- struct lp_type f32_type = lp_type_float_vec(32, 32 * i32_type.length);
- struct lp_build_context f32_bld, i32_bld;
- LLVMValueRef zero = lp_build_const_vec(gallivm, f32_type, 0.0f);
-
- lp_build_context_init(&f32_bld, gallivm, f32_type);
- lp_build_context_init(&i32_bld, gallivm, i32_type);
-
- i32_smallexpmask = lp_build_const_int_vec(gallivm, i32_type,
- ((1 << exponent_bits) - 1) << 23);
- i32_floatexpmask = lp_build_const_int_vec(gallivm, i32_type, 0xff << 23);
-
- /* "ordinary" number */
- /* clamp to pos range (can still have sign bit if NaN or negative zero) */
- clamped = lp_build_max(&f32_bld, src, zero);
- clamped = LLVMBuildBitCast(builder, clamped, i32_bld.vec_type, "");
- /* get rid of excess mantissa bits, and while here also potential sign bit */
- i32_roundmask = lp_build_const_int_vec(gallivm, i32_type,
- ~((1 << (23 - mantissa_bits)) - 1) |
- 0x7fffffff);
-
- tmp = lp_build_and(&i32_bld, clamped, i32_roundmask);
- tmp = LLVMBuildBitCast(builder, tmp, f32_bld.vec_type, "");
- /* bias exponent (and denormalize if necessary) */
- magic = lp_build_const_int_vec(gallivm, i32_type,
- ((1 << (exponent_bits - 1)) - 1) << 23);
- magic = LLVMBuildBitCast(builder, magic, f32_bld.vec_type, "");
- normal = lp_build_mul(&f32_bld, tmp, magic);
-
- /* clamp to max value */
- small_max = lp_build_const_int_vec(gallivm, i32_type,
- (((1 << exponent_bits) - 2) << 23) |
- (((1 << mantissa_bits) - 1) << (23 - mantissa_bits)));
- small_max = LLVMBuildBitCast(builder, small_max, f32_bld.vec_type, "");
- normal = lp_build_min(&f32_bld, normal, small_max);
- normal = LLVMBuildBitCast(builder, normal, i32_bld.vec_type, "");
-
- /*
- * handle nan/inf cases
- * a little bit tricky since -Inf -> 0, +Inf -> +Inf, +-Nan -> +Nan
- * Note that on a lucky day, we could simplify this a bit,
- * by just using the max(src, zero) result - this will have -Inf
- * clamped to 0, and MIGHT preserve the NaNs.
- */
- src_abs = lp_build_abs(&f32_bld, src);
- src_abs = LLVMBuildBitCast(builder, src_abs, i32_bld.vec_type, "");
- src = LLVMBuildBitCast(builder, src, i32_bld.vec_type, "");
- is_nan = lp_build_compare(gallivm, i32_type, PIPE_FUNC_GREATER,
- src_abs, i32_floatexpmask);
- is_posinf = lp_build_compare(gallivm, i32_type, PIPE_FUNC_EQUAL,
- src, i32_floatexpmask);
- is_nan_or_posinf = lp_build_and(&i32_bld, is_nan, is_posinf);
- /* could also set more mantissa bits but need at least the highest mantissa bit */
- i32_qnanbit = lp_build_const_vec(gallivm, i32_type, 1 << 22);
- /* combine maxexp with qnanbit */
- nan_or_posinf = lp_build_or(&i32_bld, i32_smallexpmask,
- lp_build_and(&i32_bld, is_nan, i32_qnanbit));
-
- return lp_build_select(&i32_bld, is_nan_or_posinf, nan_or_posinf, normal);
-}
-
-
-/**
- * Convert rgba float SoA values to packed r11g11b10 values.
- *
- * @param src SoA float (vector) values to convert.
- */
-LLVMValueRef
-lp_build_float_to_r11g11b10(struct gallivm_state *gallivm,
- LLVMValueRef *src)
-{
- LLVMValueRef dst, rcomp, bcomp, gcomp, shift, mask;
- struct lp_build_context i32_bld;
- LLVMTypeRef src_type = LLVMTypeOf(*src);
- unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
- LLVMGetVectorSize(src_type) : 1;
- struct lp_type i32_type = lp_type_int_vec(32, 32 * src_length);
-
- lp_build_context_init(&i32_bld, gallivm, i32_type);
-
- /* "rescale" - this does the actual conversion except the packing */
- rcomp = lp_build_float_to_smallfloat_nosign(gallivm, i32_type, src[0], 6, 5);
- gcomp = lp_build_float_to_smallfloat_nosign(gallivm, i32_type, src[1], 6, 5);
- bcomp = lp_build_float_to_smallfloat_nosign(gallivm, i32_type, src[2], 5, 5);
-
- /* pack rescaled SoA floats to r11g11b10 AoS values */
- shift = lp_build_const_int_vec(gallivm, i32_type, 23 - 6);
- rcomp = lp_build_shr(&i32_bld, rcomp, shift);
-
- shift = lp_build_const_int_vec(gallivm, i32_type, 23 - 17);
- mask = lp_build_const_int_vec(gallivm, i32_type, 0x7ff << 11);
- gcomp = lp_build_shr(&i32_bld, gcomp, shift);
- gcomp = lp_build_and(&i32_bld, gcomp, mask);
-
- shift = lp_build_const_int_vec(gallivm, i32_type, 27 - 23);
- mask = lp_build_const_int_vec(gallivm, i32_type, 0x3ff << 22);
- bcomp = lp_build_shl(&i32_bld, bcomp, shift);
- bcomp = lp_build_and(&i32_bld, bcomp, mask);
-
- dst = lp_build_or(&i32_bld, rcomp, gcomp);
- return lp_build_or(&i32_bld, dst, bcomp);
-}
-
-
-/**
- * Convert a float-like value with less exponent and mantissa
- * bits than a normal float32 to a float32. The mantissa of
- * the source value is assumed to have an implied 1, and the exponent
- * is biased. There are no negative values.
- * The source value to extract must be in a 32bit int.
- * While this helper is generic, it is only ever going to be useful for
- * r11g11b10 (no other common format exists with the same properties).
- *
- * @param src (vector) value to convert
- * @param mantissa_bits the number of mantissa bits
- * @param exponent_bits the number of exponent bits
- * @param mantissa_start the bit start position of the packed component
- *
- * ref http://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/
- * ref https://gist.github.com/rygorous/2156668
- */
-static LLVMValueRef
-lp_build_smallfloat_nosign_to_float(struct gallivm_state *gallivm,
- struct lp_type f32_type,
- LLVMValueRef src,
- unsigned mantissa_bits,
- unsigned exponent_bits,
- unsigned mantissa_start)
-{
- LLVMBuilderRef builder = gallivm->builder;
- LLVMValueRef smallexpmask, i32_floatexpmask, magic;
- LLVMValueRef wasinfnan, tmp, res, shift, mask;
- unsigned exponent_start = mantissa_start + mantissa_bits;
- struct lp_type i32_type = lp_type_int_vec(32, 32 * f32_type.length);
- struct lp_build_context f32_bld, i32_bld;
-
- lp_build_context_init(&f32_bld, gallivm, f32_type);
- lp_build_context_init(&i32_bld, gallivm, i32_type);
-
- /* extract the component to "float position" */
- if (exponent_start < 23) {
- shift = lp_build_const_int_vec(gallivm, i32_type, 23 - exponent_start);
- src = lp_build_shl(&i32_bld, src, shift);
- }
- else {
- shift = lp_build_const_int_vec(gallivm, i32_type, exponent_start - 23);
- src = lp_build_shr(&i32_bld, src, shift);
- }
- mask = lp_build_const_int_vec(gallivm, i32_type,
- ((1 << (mantissa_bits + exponent_bits)) - 1) <<
- (23 - mantissa_bits));
- src = lp_build_and(&i32_bld, src, mask);
- src = LLVMBuildBitCast(builder, src, f32_bld.vec_type, "");
-
- /* now do the actual scaling */
- smallexpmask = lp_build_const_int_vec(gallivm, i32_type,
- ((1 << exponent_bits) - 1) << 23);
- i32_floatexpmask = lp_build_const_int_vec(gallivm, i32_type, 0xff << 23);
- /*
- * magic number has exponent new exp bias + (new exp bias - old exp bias),
- * mantissa is 0.
- */
- magic = lp_build_const_int_vec(gallivm, i32_type,
- (255 - (1 << (exponent_bits - 1))) << 23);
- magic = LLVMBuildBitCast(builder, magic, f32_bld.vec_type, "");
-
- /* adjust exponent and fix denorms */
- res = lp_build_mul(&f32_bld, src, magic);
-
- /*
- * if exp was max (== NaN or Inf) set new exp to max (keep mantissa),
- * so a simple "or" will do (because exp adjust will leave mantissa intact)
- */
- /* use float compare (better for AVX 8-wide / no AVX2 though otherwise should use int) */
- smallexpmask = LLVMBuildBitCast(builder, magic, f32_bld.vec_type, "");
- wasinfnan = lp_build_compare(gallivm, f32_type, PIPE_FUNC_GEQUAL, src, smallexpmask);
- res = LLVMBuildBitCast(builder, res, i32_bld.vec_type, "");
- tmp = lp_build_and(&i32_bld, i32_floatexpmask, wasinfnan);
- res = lp_build_or(&i32_bld, tmp, res);
-
- return LLVMBuildBitCast(builder, res, f32_bld.vec_type, "");
-}
-
-
-/**
- * Convert packed float format (r11g11b10) value(s) to rgba float SoA values.
- *
- * @param src packed AoS r11g11b10 values (as (vector) int32)
- * @param dst pointer to the SoA result values
- */
-void
-lp_build_r11g11b10_to_float(struct gallivm_state *gallivm,
- LLVMValueRef src,
- LLVMValueRef *dst)
-{
- LLVMTypeRef src_type = LLVMTypeOf(src);
- unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
- LLVMGetVectorSize(src_type) : 1;
- struct lp_type f32_type = lp_type_float_vec(32, 32 * src_length);
-
- dst[0] = lp_build_smallfloat_nosign_to_float(gallivm, f32_type, src, 6, 5, 0);
- dst[1] = lp_build_smallfloat_nosign_to_float(gallivm, f32_type, src, 6, 5, 11);
- dst[2] = lp_build_smallfloat_nosign_to_float(gallivm, f32_type, src, 5, 5, 22);
-
- /* Just set alpha to one */
- dst[3] = lp_build_one(gallivm, f32_type);
-}
-
-
-static LLVMValueRef
-lp_build_rgb9_to_float_helper(struct gallivm_state *gallivm,
- struct lp_type f32_type,
- LLVMValueRef src,
- LLVMValueRef scale,
- unsigned mantissa_start)
-{
- LLVMValueRef shift, mask;
-
- struct lp_type i32_type = lp_type_int_vec(32, 32 * f32_type.length);
- struct lp_build_context i32_bld, f32_bld;
-
- lp_build_context_init(&i32_bld, gallivm, i32_type);
- lp_build_context_init(&f32_bld, gallivm, f32_type);
-
- /*
- * This is much easier as other weirdo float formats, since
- * there's no sign, no Inf/NaN, and there's nothing special
- * required for normals/denormals neither (as without the implied one
- * for the mantissa for other formats, everything looks like a denormal).
- * So just do (float)comp_bits * scale
- */
- shift = lp_build_const_int_vec(gallivm, i32_type, mantissa_start);
- mask = lp_build_const_int_vec(gallivm, i32_type, 0x1ff);
- src = lp_build_shr(&i32_bld, src, shift);
- src = lp_build_and(&i32_bld, src, mask);
- src = lp_build_int_to_float(&f32_bld, src);
- return lp_build_mul(&f32_bld, src, scale);
-}
-
-
-/**
- * Convert shared exponent format (rgb9e5) value(s) to rgba float SoA values.
- *
- * @param src packed AoS rgb9e5 values (as (vector) int32)
- * @param dst pointer to the SoA result values
- */
-void
-lp_build_rgb9e5_to_float(struct gallivm_state *gallivm,
- LLVMValueRef src,
- LLVMValueRef *dst)
-{
- LLVMBuilderRef builder = gallivm->builder;
- LLVMTypeRef src_type = LLVMTypeOf(src);
- LLVMValueRef shift, scale, bias, exp;
- unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
- LLVMGetVectorSize(src_type) : 1;
- struct lp_type i32_type = lp_type_int_vec(32, 32 * src_length);
- struct lp_type u32_type = lp_type_uint_vec(32, 32 * src_length);
- struct lp_type f32_type = lp_type_float_vec(32, 32 * src_length);
- struct lp_build_context i32_bld, u32_bld, f32_bld;
-
- lp_build_context_init(&i32_bld, gallivm, i32_type);
- lp_build_context_init(&u32_bld, gallivm, u32_type);
- lp_build_context_init(&f32_bld, gallivm, f32_type);
-
- /* extract exponent */
- shift = lp_build_const_int_vec(gallivm, i32_type, 27);
- /* this shift needs to be unsigned otherwise need mask */
- exp = lp_build_shr(&u32_bld, src, shift);
-
- /*
- * scale factor is 2 ^ (exp - bias)
- * (and additionally corrected here for the mantissa bits)
- * not using shift because
- * a) don't have vector shift in a lot of cases
- * b) shift direction changes hence need 2 shifts + conditional
- * (or rotate instruction which is even more rare (for instance XOP))
- * so use whacky float 2 ^ function instead manipulating exponent
- * (saves us the float conversion at the end too)
- */
- bias = lp_build_const_int_vec(gallivm, i32_type, 127 - (15 + 9));
- scale = lp_build_add(&i32_bld, exp, bias);
- shift = lp_build_const_int_vec(gallivm, i32_type, 23);
- scale = lp_build_shl(&i32_bld, scale, shift);
- scale = LLVMBuildBitCast(builder, scale, f32_bld.vec_type, "");
-
- dst[0] = lp_build_rgb9_to_float_helper(gallivm, f32_type, src, scale, 0);
- dst[1] = lp_build_rgb9_to_float_helper(gallivm, f32_type, src, scale, 9);
- dst[2] = lp_build_rgb9_to_float_helper(gallivm, f32_type, src, scale, 18);
-
- /* Just set alpha to one */
- dst[3] = f32_bld.one;
-}
-
-
-/**
* Converts int16 half-float to float32
* Note this can be performed in 1 instruction if vcvtph2ps exists (sse5 i think?)
* [llvm.x86.vcvtph2ps / _mm_cvtph_ps]
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_conv.h b/src/gallium/auxiliary/gallivm/lp_bld_conv.h
index d8bc294..d7dfed8 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_conv.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_conv.h
@@ -62,20 +62,6 @@ lp_build_float_to_half(struct gallivm_state *gallivm,
LLVMValueRef src);
LLVMValueRef
-lp_build_float_to_r11g11b10(struct gallivm_state *gallivm,
- LLVMValueRef *src);
-
-void
-lp_build_r11g11b10_to_float(struct gallivm_state *gallivm,
- LLVMValueRef src,
- LLVMValueRef *dst);
-
-void
-lp_build_rgb9e5_to_float(struct gallivm_state *gallivm,
- LLVMValueRef src,
- LLVMValueRef *dst);
-
-LLVMValueRef
lp_build_clamped_float_to_unsigned_norm(struct gallivm_state *gallivm,
struct lp_type src_type,
unsigned dst_width,
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_format.h b/src/gallium/auxiliary/gallivm/lp_bld_format.h
index 8fb173b..f9ddc68 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_format.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_format.h
@@ -122,4 +122,22 @@ lp_build_fetch_subsampled_rgba_aos(struct gallivm_state *gallivm,
LLVMValueRef i,
LLVMValueRef j);
+/*
+ * special float formats
+ */
+
+LLVMValueRef
+lp_build_float_to_r11g11b10(struct gallivm_state *gallivm,
+ LLVMValueRef *src);
+
+void
+lp_build_r11g11b10_to_float(struct gallivm_state *gallivm,
+ LLVMValueRef src,
+ LLVMValueRef *dst);
+
+void
+lp_build_rgb9e5_to_float(struct gallivm_state *gallivm,
+ LLVMValueRef src,
+ LLVMValueRef *dst);
+
#endif /* !LP_BLD_FORMAT_H */
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_format_float.c b/src/gallium/auxiliary/gallivm/lp_bld_format_float.c
new file mode 100644
index 0000000..efab344
--- /dev/null
+++ b/src/gallium/auxiliary/gallivm/lp_bld_format_float.c
@@ -0,0 +1,373 @@
+/**************************************************************************
+ *
+ * Copyright 2013 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * 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, sub license, 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 (including the
+ * next paragraph) 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 NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS 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.
+ *
+ **************************************************************************/
+
+
+/**
+ * @file
+ * Format conversion code for "special" float formats.
+ *
+ * @author Roland Scheidegger <sroland at vmware.com>
+ */
+
+
+#include "util/u_debug.h"
+
+#include "lp_bld_type.h"
+#include "lp_bld_const.h"
+#include "lp_bld_arit.h"
+#include "lp_bld_bitarit.h"
+#include "lp_bld_logic.h"
+#include "lp_bld_format.h"
+
+
+/**
+ * Convert float32 to a float-like value with less exponent and mantissa
+ * bits. The mantissa is still biased, and the mantissa still has an implied 1,
+ * but there's no sign bit.
+ *
+ * @param src (vector) float value to convert
+ * @param mantissa_bits the number of mantissa bits
+ * @param exponent_bits the number of exponent bits
+ *
+ * Unlike float_to_half using accurate method here.
+ * This implements round-towards-zero (trunc) hence too large numbers get
+ * converted to largest representable number, not infinity.
+ * Small numbers may get converted to denorms, depending on normal
+ * float denorm handling of the cpu.
+ * Note that compared to the references, below, we skip any rounding bias
+ * since we do rounding towards zero - OpenGL allows rounding towards zero
+ * (though not preferred) and DX10 even seems to require it.
+ * Note that this will not do any packing - the value will
+ * look like a "rescaled float" (except for Inf/NaN) but be returned
+ * as int32.
+ *
+ * ref http://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/
+ * ref https://gist.github.com/rygorous/2156668
+ */
+static LLVMValueRef
+lp_build_float_to_smallfloat_nosign(struct gallivm_state *gallivm,
+ struct lp_type i32_type,
+ LLVMValueRef src,
+ unsigned mantissa_bits,
+ unsigned exponent_bits)
+{
+ LLVMBuilderRef builder = gallivm->builder;
+ LLVMValueRef i32_floatexpmask, i32_smallexpmask, magic, normal;
+ LLVMValueRef clamped, tmp, i32_roundmask, small_max, src_abs;
+ LLVMValueRef is_nan, is_posinf, is_nan_or_posinf, i32_qnanbit, nan_or_posinf;
+ struct lp_type f32_type = lp_type_float_vec(32, 32 * i32_type.length);
+ struct lp_build_context f32_bld, i32_bld;
+ LLVMValueRef zero = lp_build_const_vec(gallivm, f32_type, 0.0f);
+
+ lp_build_context_init(&f32_bld, gallivm, f32_type);
+ lp_build_context_init(&i32_bld, gallivm, i32_type);
+
+ i32_smallexpmask = lp_build_const_int_vec(gallivm, i32_type,
+ ((1 << exponent_bits) - 1) << 23);
+ i32_floatexpmask = lp_build_const_int_vec(gallivm, i32_type, 0xff << 23);
+
+ /* "ordinary" number */
+ /* clamp to pos range (can still have sign bit if NaN or negative zero) */
+ clamped = lp_build_max(&f32_bld, src, zero);
+ clamped = LLVMBuildBitCast(builder, clamped, i32_bld.vec_type, "");
+ /* get rid of excess mantissa bits, and while here also potential sign bit */
+ i32_roundmask = lp_build_const_int_vec(gallivm, i32_type,
+ ~((1 << (23 - mantissa_bits)) - 1) |
+ 0x7fffffff);
+
+ tmp = lp_build_and(&i32_bld, clamped, i32_roundmask);
+ tmp = LLVMBuildBitCast(builder, tmp, f32_bld.vec_type, "");
+ /* bias exponent (and denormalize if necessary) */
+ magic = lp_build_const_int_vec(gallivm, i32_type,
+ ((1 << (exponent_bits - 1)) - 1) << 23);
+ magic = LLVMBuildBitCast(builder, magic, f32_bld.vec_type, "");
+ normal = lp_build_mul(&f32_bld, tmp, magic);
+
+ /* clamp to max value */
+ small_max = lp_build_const_int_vec(gallivm, i32_type,
+ (((1 << exponent_bits) - 2) << 23) |
+ (((1 << mantissa_bits) - 1) << (23 - mantissa_bits)));
+ small_max = LLVMBuildBitCast(builder, small_max, f32_bld.vec_type, "");
+ normal = lp_build_min(&f32_bld, normal, small_max);
+ normal = LLVMBuildBitCast(builder, normal, i32_bld.vec_type, "");
+
+ /*
+ * handle nan/inf cases
+ * a little bit tricky since -Inf -> 0, +Inf -> +Inf, +-Nan -> +Nan
+ * Note that on a lucky day, we could simplify this a bit,
+ * by just using the max(src, zero) result - this will have -Inf
+ * clamped to 0, and MIGHT preserve the NaNs.
+ */
+ src_abs = lp_build_abs(&f32_bld, src);
+ src_abs = LLVMBuildBitCast(builder, src_abs, i32_bld.vec_type, "");
+ src = LLVMBuildBitCast(builder, src, i32_bld.vec_type, "");
+ is_nan = lp_build_compare(gallivm, i32_type, PIPE_FUNC_GREATER,
+ src_abs, i32_floatexpmask);
+ is_posinf = lp_build_compare(gallivm, i32_type, PIPE_FUNC_EQUAL,
+ src, i32_floatexpmask);
+ is_nan_or_posinf = lp_build_and(&i32_bld, is_nan, is_posinf);
+ /* could also set more mantissa bits but need at least the highest mantissa bit */
+ i32_qnanbit = lp_build_const_vec(gallivm, i32_type, 1 << 22);
+ /* combine maxexp with qnanbit */
+ nan_or_posinf = lp_build_or(&i32_bld, i32_smallexpmask,
+ lp_build_and(&i32_bld, is_nan, i32_qnanbit));
+
+ return lp_build_select(&i32_bld, is_nan_or_posinf, nan_or_posinf, normal);
+}
+
+
+/**
+ * Convert rgba float SoA values to packed r11g11b10 values.
+ *
+ * @param src SoA float (vector) values to convert.
+ */
+LLVMValueRef
+lp_build_float_to_r11g11b10(struct gallivm_state *gallivm,
+ LLVMValueRef *src)
+{
+ LLVMValueRef dst, rcomp, bcomp, gcomp, shift, mask;
+ struct lp_build_context i32_bld;
+ LLVMTypeRef src_type = LLVMTypeOf(*src);
+ unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
+ LLVMGetVectorSize(src_type) : 1;
+ struct lp_type i32_type = lp_type_int_vec(32, 32 * src_length);
+
+ lp_build_context_init(&i32_bld, gallivm, i32_type);
+
+ /* "rescale" - this does the actual conversion except the packing */
+ rcomp = lp_build_float_to_smallfloat_nosign(gallivm, i32_type, src[0], 6, 5);
+ gcomp = lp_build_float_to_smallfloat_nosign(gallivm, i32_type, src[1], 6, 5);
+ bcomp = lp_build_float_to_smallfloat_nosign(gallivm, i32_type, src[2], 5, 5);
+
+ /* pack rescaled SoA floats to r11g11b10 AoS values */
+ shift = lp_build_const_int_vec(gallivm, i32_type, 23 - 6);
+ rcomp = lp_build_shr(&i32_bld, rcomp, shift);
+
+ shift = lp_build_const_int_vec(gallivm, i32_type, 23 - 17);
+ mask = lp_build_const_int_vec(gallivm, i32_type, 0x7ff << 11);
+ gcomp = lp_build_shr(&i32_bld, gcomp, shift);
+ gcomp = lp_build_and(&i32_bld, gcomp, mask);
+
+ shift = lp_build_const_int_vec(gallivm, i32_type, 27 - 23);
+ mask = lp_build_const_int_vec(gallivm, i32_type, 0x3ff << 22);
+ bcomp = lp_build_shl(&i32_bld, bcomp, shift);
+ bcomp = lp_build_and(&i32_bld, bcomp, mask);
+
+ dst = lp_build_or(&i32_bld, rcomp, gcomp);
+ return lp_build_or(&i32_bld, dst, bcomp);
+}
+
+
+/**
+ * Convert a float-like value with less exponent and mantissa
+ * bits than a normal float32 to a float32. The mantissa of
+ * the source value is assumed to have an implied 1, and the exponent
+ * is biased. There are no negative values.
+ * The source value to extract must be in a 32bit int.
+ * While this helper is generic, it is only ever going to be useful for
+ * r11g11b10 (no other common format exists with the same properties).
+ *
+ * @param src (vector) value to convert
+ * @param mantissa_bits the number of mantissa bits
+ * @param exponent_bits the number of exponent bits
+ * @param mantissa_start the bit start position of the packed component
+ *
+ * ref http://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/
+ * ref https://gist.github.com/rygorous/2156668
+ */
+static LLVMValueRef
+lp_build_smallfloat_nosign_to_float(struct gallivm_state *gallivm,
+ struct lp_type f32_type,
+ LLVMValueRef src,
+ unsigned mantissa_bits,
+ unsigned exponent_bits,
+ unsigned mantissa_start)
+{
+ LLVMBuilderRef builder = gallivm->builder;
+ LLVMValueRef smallexpmask, i32_floatexpmask, magic;
+ LLVMValueRef wasinfnan, tmp, res, shift, mask;
+ unsigned exponent_start = mantissa_start + mantissa_bits;
+ struct lp_type i32_type = lp_type_int_vec(32, 32 * f32_type.length);
+ struct lp_build_context f32_bld, i32_bld;
+
+ lp_build_context_init(&f32_bld, gallivm, f32_type);
+ lp_build_context_init(&i32_bld, gallivm, i32_type);
+
+ /* extract the component to "float position" */
+ if (exponent_start < 23) {
+ shift = lp_build_const_int_vec(gallivm, i32_type, 23 - exponent_start);
+ src = lp_build_shl(&i32_bld, src, shift);
+ }
+ else {
+ shift = lp_build_const_int_vec(gallivm, i32_type, exponent_start - 23);
+ src = lp_build_shr(&i32_bld, src, shift);
+ }
+ mask = lp_build_const_int_vec(gallivm, i32_type,
+ ((1 << (mantissa_bits + exponent_bits)) - 1) <<
+ (23 - mantissa_bits));
+ src = lp_build_and(&i32_bld, src, mask);
+ src = LLVMBuildBitCast(builder, src, f32_bld.vec_type, "");
+
+ /* now do the actual scaling */
+ smallexpmask = lp_build_const_int_vec(gallivm, i32_type,
+ ((1 << exponent_bits) - 1) << 23);
+ i32_floatexpmask = lp_build_const_int_vec(gallivm, i32_type, 0xff << 23);
+ /*
+ * magic number has exponent new exp bias + (new exp bias - old exp bias),
+ * mantissa is 0.
+ */
+ magic = lp_build_const_int_vec(gallivm, i32_type,
+ (255 - (1 << (exponent_bits - 1))) << 23);
+ magic = LLVMBuildBitCast(builder, magic, f32_bld.vec_type, "");
+
+ /* adjust exponent and fix denorms */
+ res = lp_build_mul(&f32_bld, src, magic);
+
+ /*
+ * if exp was max (== NaN or Inf) set new exp to max (keep mantissa),
+ * so a simple "or" will do (because exp adjust will leave mantissa intact)
+ */
+ /* use float compare (better for AVX 8-wide / no AVX2 though otherwise should use int) */
+ smallexpmask = LLVMBuildBitCast(builder, magic, f32_bld.vec_type, "");
+ wasinfnan = lp_build_compare(gallivm, f32_type, PIPE_FUNC_GEQUAL, src, smallexpmask);
+ res = LLVMBuildBitCast(builder, res, i32_bld.vec_type, "");
+ tmp = lp_build_and(&i32_bld, i32_floatexpmask, wasinfnan);
+ res = lp_build_or(&i32_bld, tmp, res);
+
+ return LLVMBuildBitCast(builder, res, f32_bld.vec_type, "");
+}
+
+
+/**
+ * Convert packed float format (r11g11b10) value(s) to rgba float SoA values.
+ *
+ * @param src packed AoS r11g11b10 values (as (vector) int32)
+ * @param dst pointer to the SoA result values
+ */
+void
+lp_build_r11g11b10_to_float(struct gallivm_state *gallivm,
+ LLVMValueRef src,
+ LLVMValueRef *dst)
+{
+ LLVMTypeRef src_type = LLVMTypeOf(src);
+ unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
+ LLVMGetVectorSize(src_type) : 1;
+ struct lp_type f32_type = lp_type_float_vec(32, 32 * src_length);
+
+ dst[0] = lp_build_smallfloat_nosign_to_float(gallivm, f32_type, src, 6, 5, 0);
+ dst[1] = lp_build_smallfloat_nosign_to_float(gallivm, f32_type, src, 6, 5, 11);
+ dst[2] = lp_build_smallfloat_nosign_to_float(gallivm, f32_type, src, 5, 5, 22);
+
+ /* Just set alpha to one */
+ dst[3] = lp_build_one(gallivm, f32_type);
+}
+
+
+static LLVMValueRef
+lp_build_rgb9_to_float_helper(struct gallivm_state *gallivm,
+ struct lp_type f32_type,
+ LLVMValueRef src,
+ LLVMValueRef scale,
+ unsigned mantissa_start)
+{
+ LLVMValueRef shift, mask;
+
+ struct lp_type i32_type = lp_type_int_vec(32, 32 * f32_type.length);
+ struct lp_build_context i32_bld, f32_bld;
+
+ lp_build_context_init(&i32_bld, gallivm, i32_type);
+ lp_build_context_init(&f32_bld, gallivm, f32_type);
+
+ /*
+ * This is much easier as other weirdo float formats, since
+ * there's no sign, no Inf/NaN, and there's nothing special
+ * required for normals/denormals neither (as without the implied one
+ * for the mantissa for other formats, everything looks like a denormal).
+ * So just do (float)comp_bits * scale
+ */
+ shift = lp_build_const_int_vec(gallivm, i32_type, mantissa_start);
+ mask = lp_build_const_int_vec(gallivm, i32_type, 0x1ff);
+ src = lp_build_shr(&i32_bld, src, shift);
+ src = lp_build_and(&i32_bld, src, mask);
+ src = lp_build_int_to_float(&f32_bld, src);
+ return lp_build_mul(&f32_bld, src, scale);
+}
+
+
+/**
+ * Convert shared exponent format (rgb9e5) value(s) to rgba float SoA values.
+ *
+ * @param src packed AoS rgb9e5 values (as (vector) int32)
+ * @param dst pointer to the SoA result values
+ */
+void
+lp_build_rgb9e5_to_float(struct gallivm_state *gallivm,
+ LLVMValueRef src,
+ LLVMValueRef *dst)
+{
+ LLVMBuilderRef builder = gallivm->builder;
+ LLVMTypeRef src_type = LLVMTypeOf(src);
+ LLVMValueRef shift, scale, bias, exp;
+ unsigned src_length = LLVMGetTypeKind(src_type) == LLVMVectorTypeKind ?
+ LLVMGetVectorSize(src_type) : 1;
+ struct lp_type i32_type = lp_type_int_vec(32, 32 * src_length);
+ struct lp_type u32_type = lp_type_uint_vec(32, 32 * src_length);
+ struct lp_type f32_type = lp_type_float_vec(32, 32 * src_length);
+ struct lp_build_context i32_bld, u32_bld, f32_bld;
+
+ lp_build_context_init(&i32_bld, gallivm, i32_type);
+ lp_build_context_init(&u32_bld, gallivm, u32_type);
+ lp_build_context_init(&f32_bld, gallivm, f32_type);
+
+ /* extract exponent */
+ shift = lp_build_const_int_vec(gallivm, i32_type, 27);
+ /* this shift needs to be unsigned otherwise need mask */
+ exp = lp_build_shr(&u32_bld, src, shift);
+
+ /*
+ * scale factor is 2 ^ (exp - bias)
+ * (and additionally corrected here for the mantissa bits)
+ * not using shift because
+ * a) don't have vector shift in a lot of cases
+ * b) shift direction changes hence need 2 shifts + conditional
+ * (or rotate instruction which is even more rare (for instance XOP))
+ * so use whacky float 2 ^ function instead manipulating exponent
+ * (saves us the float conversion at the end too)
+ */
+ bias = lp_build_const_int_vec(gallivm, i32_type, 127 - (15 + 9));
+ scale = lp_build_add(&i32_bld, exp, bias);
+ shift = lp_build_const_int_vec(gallivm, i32_type, 23);
+ scale = lp_build_shl(&i32_bld, scale, shift);
+ scale = LLVMBuildBitCast(builder, scale, f32_bld.vec_type, "");
+
+ dst[0] = lp_build_rgb9_to_float_helper(gallivm, f32_type, src, scale, 0);
+ dst[1] = lp_build_rgb9_to_float_helper(gallivm, f32_type, src, scale, 9);
+ dst[2] = lp_build_rgb9_to_float_helper(gallivm, f32_type, src, scale, 18);
+
+ /* Just set alpha to one */
+ dst[3] = f32_bld.one;
+}
--
1.7.9.5
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