nir: Add the start of a format conversion helper header

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>

src/compiler/Makefile.sources

@@ -202,6 +202,7 @@ NIR_FILES = \
 	nir/nir_control_flow.h \
 	nir/nir_control_flow_private.h \
 	nir/nir_dominance.c \
+	nir/nir_format_convert.h \
 	nir/nir_from_ssa.c \
 	nir/nir_gather_info.c \
 	nir/nir_gs_count_vertices.c \

src/compiler/nir/meson.build

@@ -93,6 +93,7 @@ files_libnir = files(
   'nir_control_flow.h',
   'nir_control_flow_private.h',
   'nir_dominance.c',
+  'nir_format_convert.h',
   'nir_from_ssa.c',
   'nir_gather_info.c',
   'nir_gs_count_vertices.c',

src/compiler/nir/nir_format_convert.h

@@ -0,0 +1,106 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * 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 (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 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 "nir_builder.h"
+
+static inline nir_ssa_def *
+nir_shift(nir_builder *b, nir_ssa_def *value, int left_shift)
+{
+   if (left_shift > 0)
+      return nir_ishl(b, value, nir_imm_int(b, left_shift));
+   else if (left_shift < 0)
+      return nir_ushr(b, value, nir_imm_int(b, -left_shift));
+   else
+      return value;
+}
+
+static inline nir_ssa_def *
+nir_mask_shift(struct nir_builder *b, nir_ssa_def *src,
+               uint32_t mask, int left_shift)
+{
+   return nir_shift(b, nir_iand(b, src, nir_imm_int(b, mask)), left_shift);
+}
+
+static inline nir_ssa_def *
+nir_mask_shift_or(struct nir_builder *b, nir_ssa_def *dst, nir_ssa_def *src,
+                  uint32_t src_mask, int src_left_shift)
+{
+   return nir_ior(b, nir_mask_shift(b, src, src_mask, src_left_shift), dst);
+}
+
+static inline nir_ssa_def *
+nir_format_unpack_uint(nir_builder *b, nir_ssa_def *packed,
+                       const unsigned *bits, unsigned num_components)
+{
+   assert(num_components >= 1 && num_components <= 4);
+   nir_ssa_def *comps[4];
+
+   if (bits[0] >= packed->bit_size) {
+      assert(bits[0] == packed->bit_size);
+      assert(num_components == 1);
+      return packed;
+   }
+
+   unsigned offset = 0;
+   for (unsigned i = 0; i < num_components; i++) {
+      assert(bits[i] < 32);
+      nir_ssa_def *mask = nir_imm_int(b, (1u << bits[i]) - 1);
+      comps[i] = nir_iand(b, nir_shift(b, packed, -offset), mask);
+      offset += bits[i];
+   }
+   assert(offset <= packed->bit_size);
+
+   return nir_vec(b, comps, num_components);
+}
+
+static inline nir_ssa_def *
+nir_format_pack_uint_unmasked(nir_builder *b, nir_ssa_def *color,
+                              const unsigned *bits, unsigned num_components)
+{
+   assert(num_components >= 1 && num_components <= 4);
+   nir_ssa_def *packed = nir_imm_int(b, 0);
+   unsigned offset = 0;
+   for (unsigned i = 0; i < num_components; i++) {
+      packed = nir_ior(b, packed, nir_shift(b, nir_channel(b, color, i),
+                                               offset));
+      offset += bits[i];
+   }
+   assert(offset <= packed->bit_size);
+
+   return packed;
+}
+
+static inline nir_ssa_def *
+nir_format_pack_uint(nir_builder *b, nir_ssa_def *color,
+                     const unsigned *bits, unsigned num_components)
+{
+   nir_const_value mask;
+   for (unsigned i = 0; i < num_components; i++) {
+      assert(bits[i] < 32);
+      mask.u32[i] = (1u << bits[i]) - 1;
+   }
+   nir_ssa_def *mask_imm = nir_build_imm(b, num_components, 32, mask);
+
+   return nir_format_pack_uint_unmasked(b, nir_iand(b, color, mask_imm),
+                                        bits, num_components);
+}