nir/large_constants: Properly handle 1-bit bools

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

1 files changed, 23 insertions, 1 deletions

diff --git a/src/compiler/nir/nir_opt_large_constants.c b/src/compiler/nir/nir_opt_large_constants.c
index 634913aa9e5..aa22f05d809 100644
--- a/src/compiler/nir/nir_opt_large_constants.c
+++ b/src/compiler/nir/nir_opt_large_constants.c
@@ -53,7 +53,23 @@ build_constant_load(nir_builder *b, nir_deref_instr *deref,
                      num_components, bit_size, NULL);
    nir_builder_instr_insert(b, &load->instr);
 
-   return &load->dest.ssa;
+   if (load->dest.ssa.bit_size < 8) {
+      /* Booleans are special-cased to be 32-bit
+       *
+       * Ideally, for drivers that can handle 32-bit booleans, we wouldn't
+       * emit the i2b here.  However, at this point, the driver is likely to
+       * still have 1-bit booleans so we need to at least convert bit sizes.
+       * Unfortunately, we don't have a good way to annotate the load as
+       * loading a known boolean value so the optimizer isn't going to be
+       * able to get rid of the conversion.  Some day, we may solve that
+       * problem but not today.
+       */
+      assert(glsl_type_is_boolean(deref->type));
+      load->dest.ssa.bit_size = 32;
+      return nir_i2b(b, &load->dest.ssa);
+   } else {
+      return &load->dest.ssa;
+   }
 }
 
 static void
@@ -74,6 +90,12 @@ handle_constant_store(nir_builder *b, nir_intrinsic_instr *store,
 
    nir_const_value *val = nir_src_as_const_value(store->src[1]);
    switch (bit_size) {
+   case 1:
+      /* Booleans are special-cased to be 32-bit */
+      for (unsigned i = 0; i < num_components; i++)
+         ((int32_t *)dst)[i] = -(int)val->b[i];
+      break;
+
    case 8:
       for (unsigned i = 0; i < num_components; i++)
          ((uint8_t *)dst)[i] = val->u8[i];