pco: add support for sscaled8* formats

Signed-off-by: Simon Perretta <simon.perretta@imgtec.com>
Acked-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36412>

src/compiler/nir/nir_constant_expressions.py

@@ -284,6 +284,15 @@ unpack_unorm_1x16(uint16_t u)
    return (float) u / 65535.0f;
 }
 
+/**
+ * Evaluate one component of unpackSscaled4x8.
+ */
+static float
+unpack_sscaled_1x8(uint8_t u)
+{
+   return CLAMP((int8_t) u, -128.0f, +127.0f);
+}
+
 /**
  * Evaluate one component of packHalf2x16.
  */

src/compiler/nir/nir_lower_alu_width.c

@@ -279,9 +279,12 @@ lower_alu_instr_width(nir_builder *b, nir_instr *instr, void *_data)
       return NULL;
 
    case nir_op_unpack_snorm_8_8:
+   case nir_op_unpack_sscaled_8_8:
    case nir_op_unpack_unorm_8_8:
    case nir_op_unpack_snorm_8_8_8:
+   case nir_op_unpack_sscaled_8_8_8:
    case nir_op_unpack_unorm_8_8_8:
+   case nir_op_unpack_sscaled_8_8_8_8:
    case nir_op_unpack_unorm_10_10_10_2:
    case nir_op_unpack_float_11_11_10:
       return NULL;

src/compiler/nir/nir_opcodes.py

@@ -1883,14 +1883,19 @@ dst.w = unpack_{fmt}_1x{a}((src0.x >> {r + g + b}) & ((1u << {a}) - 1));
 """)
 
 unpack_r("snorm", 8)
+unpack_r("sscaled", 8)
 unpack_r("unorm", 8)
 
 unpack_rg("snorm", 8, 8)
+unpack_rg("sscaled", 8, 8)
 unpack_rg("unorm", 8, 8)
 
 unpack_rgb("snorm", 8, 8, 8)
+unpack_rgb("sscaled", 8, 8, 8)
 unpack_rgb("unorm", 8, 8, 8)
 
+unpack_rgba("sscaled", 8, 8, 8, 8)
+
 unpack_r("snorm", 16)
 unpack_r("unorm", 16)
 

src/imagination/pco/pco_nir_pvfio.c

@@ -401,6 +401,26 @@ static nir_def *unpack_from_format(nir_builder *b,
       unpacked = nir_unpack_snorm_4x8(b, input);
       break;
 
+   case PIPE_FORMAT_R8_SSCALED:
+      assert(dest_type == nir_type_float);
+      unpacked = nir_unpack_sscaled_8(b, input);
+      break;
+
+   case PIPE_FORMAT_R8G8_SSCALED:
+      assert(dest_type == nir_type_float);
+      unpacked = nir_unpack_sscaled_8_8(b, input);
+      break;
+
+   case PIPE_FORMAT_R8G8B8_SSCALED:
+      assert(dest_type == nir_type_float);
+      unpacked = nir_unpack_sscaled_8_8_8(b, input);
+      break;
+
+   case PIPE_FORMAT_R8G8B8A8_SSCALED:
+      assert(dest_type == nir_type_float);
+      unpacked = nir_unpack_sscaled_8_8_8_8(b, input);
+      break;
+
    case PIPE_FORMAT_R8G8B8A8_UINT:
       unpacked = nir_vector_insert_imm(
          b,

src/imagination/pco/pco_trans_nir.c

@@ -2249,6 +2249,38 @@ static pco_instr *trans_alu(trans_ctx *tctx, nir_alu_instr *alu)
                         .scale = true);
       break;
 
+   case nir_op_unpack_sscaled_8:
+      instr = pco_unpck(&tctx->b,
+                        dest,
+                        pco_ref_elem(src[0], 0),
+                        .rpt = 1,
+                        .pck_fmt = PCO_PCK_FMT_S8888);
+      break;
+
+   case nir_op_unpack_sscaled_8_8:
+      instr = pco_unpck(&tctx->b,
+                        dest,
+                        pco_ref_elem(src[0], 0),
+                        .rpt = 2,
+                        .pck_fmt = PCO_PCK_FMT_S8888);
+      break;
+
+   case nir_op_unpack_sscaled_8_8_8:
+      instr = pco_unpck(&tctx->b,
+                        dest,
+                        pco_ref_elem(src[0], 0),
+                        .rpt = 3,
+                        .pck_fmt = PCO_PCK_FMT_S8888);
+      break;
+
+   case nir_op_unpack_sscaled_8_8_8_8:
+      instr = pco_unpck(&tctx->b,
+                        dest,
+                        pco_ref_elem(src[0], 0),
+                        .rpt = 4,
+                        .pck_fmt = PCO_PCK_FMT_S8888);
+      break;
+
    case nir_op_pack_unorm_8:
       instr = pco_pck(&tctx->b,
                       dest,