nir: Add support for 1-bit data types

This commit adds support for 1-bit Booleans and integers.  Booleans
obviously take a value of true or false.  Because we have to define the
semantics of 1-bit signed and unsigned integers, we define uint1_t to
take values of 0 and 1 and int1_t to take values of 0 and -1.  1-bit
arithmetic is then well-defined in the usual way, just with fewer bits.
The definition of int1_t and uint1_t doesn't usually matter but we do
need something for purposes of constant folding.

Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Bas Nieuwenhuizen <[email protected]>
Tested-by: Bas Nieuwenhuizen <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/compiler/nir/nir_search.c b/src/compiler/nir/nir_search.c
index c7954b39415..50f5464cef8 100644
--- a/src/compiler/nir/nir_search.c
+++ b/src/compiler/nir/nir_search.c
@@ -476,8 +476,9 @@ construct_value(nir_builder *build,
          break;
 
       case nir_type_bool:
-         cval = nir_imm_bool(build, c->data.u);
+         cval = nir_imm_boolN_t(build, c->data.u, bit_size);
          break;
+
       default:
          unreachable("Invalid alu source type");
       }