gallium/ntt: Add default compiler options for non-native-NIR drivers.

For using NIR internally in mesa/st, we need some compiler options.  This
is the options wrote for softpipe, which should be enough for whatever NTT
we do.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6477>

src/gallium/auxiliary/nir/nir_to_tgsi.c

@@ -2645,3 +2645,29 @@ nir_to_tgsi(struct nir_shader *s,
 
    return tgsi_tokens;
 }
+
+static const nir_shader_compiler_options nir_to_tgsi_compiler_options = {
+   .fuse_ffma32 = true,
+   .fuse_ffma64 = true,
+   .lower_extract_byte = true,
+   .lower_extract_word = true,
+   .lower_fdph = true,
+   .lower_flrp64 = true,
+   .lower_fmod = true,
+   .lower_rotate = true,
+   .lower_sub = true,
+   .lower_vector_cmp = true,
+   .use_interpolated_input_intrinsics = true,
+};
+
+/* Returns a default compiler options for drivers with only nir-to-tgsi-based
+ * NIR support.
+ */
+const void *
+nir_to_tgsi_get_compiler_options(struct pipe_screen *pscreen,
+                                 enum pipe_shader_ir ir,
+                                 unsigned shader)
+{
+   assert(ir == PIPE_SHADER_IR_NIR);
+   return &nir_to_tgsi_compiler_options;
+}

src/gallium/auxiliary/nir/nir_to_tgsi.h

@@ -30,4 +30,9 @@ struct pipe_screen;
 const void *nir_to_tgsi(struct nir_shader *s,
                         struct pipe_screen *screen);
 
+const void *
+nir_to_tgsi_get_compiler_options(struct pipe_screen *pscreen,
+                                 enum pipe_shader_ir ir,
+                                 unsigned shader);
+
 #endif /* NIR_TO_TGSI_H */