nir: Report progress properly in nir_lower_bool_to_*

All three passes have the same bug where, in the mov/vec case they
unconditionally return true even if they don't change anything.  Throw
in a bit size check so they return false properly.

Reviewed-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6435>

src/compiler/nir/nir_lower_bool_to_bitsize.c

@@ -110,7 +110,7 @@ lower_alu_instr(nir_builder *b, nir_alu_instr *alu)
    case nir_op_ior:
    case nir_op_ixor:
       if (nir_dest_bit_size(alu->dest.dest) > 1)
-         break; /* Not a boolean instruction */
+         return false; /* Not a boolean instruction */
       /* Fallthrough */
 
    case nir_op_ball_fequal2:

src/compiler/nir/nir_lower_bool_to_float.c

@@ -58,6 +58,8 @@ lower_alu_instr(nir_builder *b, nir_alu_instr *alu)
    case nir_op_vec4:
    case nir_op_vec8:
    case nir_op_vec16:
+      if (alu->dest.dest.ssa.bit_size != 1)
+         return false;
       /* These we expect to have booleans but the opcode doesn't change */
       break;
 

src/compiler/nir/nir_lower_bool_to_int32.c

@@ -59,6 +59,8 @@ lower_alu_instr(nir_alu_instr *alu)
    case nir_op_iand:
    case nir_op_ior:
    case nir_op_ixor:
+      if (alu->dest.dest.ssa.bit_size != 1)
+         return false;
       /* These we expect to have booleans but the opcode doesn't change */
       break;