bi: Implement basic 8-bit vec support

Not the most efficient approach but functional.

Signed-off-by: Mary Guillemard <mary.guillemard@collabora.com>
Acked-by: Rebecca Mckeever <rebecca.mckeever@collabora.com>
Reviewed by: Eric R. Smith <eric.smith@collabora.com>

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30088>

1 files changed, 35 insertions, 4 deletions

diff --git a/src/panfrost/compiler/bifrost_compile.c b/src/panfrost/compiler/bifrost_compile.c
index e25ca71f9b0..10088656e6f 100644
--- a/src/panfrost/compiler/bifrost_compile.c
+++ b/src/panfrost/compiler/bifrost_compile.c
@@ -647,8 +647,20 @@ bi_make_vec8_helper(bi_builder *b, bi_index *src, unsigned *channel,
 
    for (unsigned i = 0; i < count; ++i) {
       unsigned chan = channel ? channel[i] : 0;
+      unsigned lane = chan & 3;
+      bi_index raw_data = bi_extract(b, src[i], chan >> 2);
+
+      /* On Bifrost, MKVEC.v4i8 cannot select b1 or b3 */
+      if (b->shader->arch < 9 && lane != 0 && lane != 2) {
+         bytes[i] = bi_byte(bi_rshift_or(b, 32, raw_data, bi_zero(),
+                                         bi_imm_u8(lane * 8), false),
+                            0);
+      } else {
+         bytes[i] = bi_byte(raw_data, lane);
+      }
 
-      bytes[i] = bi_byte(bi_extract(b, src[i], chan >> 2), chan & 3);
+      assert(b->shader->arch >= 9 || bytes[i].swizzle == BI_SWIZZLE_B0000 ||
+             bytes[i].swizzle == BI_SWIZZLE_B2222);
    }
 
    if (b->shader->arch >= 9) {
@@ -1884,10 +1896,29 @@ bi_alu_src_index(bi_builder *b, nir_alu_src src, unsigned comps)
       unsigned c0 = src.swizzle[0] & 1;
       unsigned c1 = (comps > 1) ? src.swizzle[1] & 1 : c0;
       idx.swizzle = BI_SWIZZLE_H00 + c1 + (c0 << 1);
-   } else if (bitsize == 8) {
-      /* 8-bit vectors not yet supported */
-      assert(comps == 1 && "8-bit vectors not supported");
+   } else if (bitsize == 8 && comps == 1) {
       idx.swizzle = BI_SWIZZLE_B0000 + (src.swizzle[0] & 3);
+   } else if (bitsize == 8) {
+      /* XXX: Use optimized swizzle when posisble */
+      bi_index unoffset_srcs[NIR_MAX_VEC_COMPONENTS] = {bi_null()};
+      unsigned channels[NIR_MAX_VEC_COMPONENTS] = {0};
+
+      for (unsigned i = 0; i < comps; ++i) {
+         unoffset_srcs[i] = bi_src_index(&src.src);
+         channels[i] = src.swizzle[i];
+      }
+
+      bi_index temp = bi_temp(b->shader);
+      bi_make_vec_to(b, temp, unoffset_srcs, channels, comps, bitsize);
+
+      static const enum bi_swizzle swizzle_lut[] = {
+         BI_SWIZZLE_B0000, BI_SWIZZLE_B0011, BI_SWIZZLE_H01, BI_SWIZZLE_H01};
+      assert(comps - 1 < ARRAY_SIZE(swizzle_lut));
+
+      /* Assign a coherent swizzle for the vector */
+      temp.swizzle = swizzle_lut[comps - 1];
+
+      return temp;
    }
 
    return idx;