nir/builder: Add an init function that creates a simple shader for you

A hugely common case when using nir_builder is to have a shader with a
single function called main.  This adds a helper that gives you just that.
This commit also makes us use it in the NIR control-flow unit tests as well
as tgsi_to_nir and prog_to_nir.

Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Connor Abbott <[email protected]>
Acked-by: Kenneth Graunke <[email protected]>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/glsl/nir/nir_builder.h b/src/glsl/nir/nir_builder.h
index ee6131a089f..cfaaf8e03e3 100644
--- a/src/glsl/nir/nir_builder.h
+++ b/src/glsl/nir/nir_builder.h
@@ -44,6 +44,17 @@ nir_builder_init(nir_builder *build, nir_function_impl *impl)
 }
 
 static inline void
+nir_builder_init_simple_shader(nir_builder *build, void *mem_ctx,
+                               gl_shader_stage stage,
+                               const nir_shader_compiler_options *options)
+{
+   build->shader = nir_shader_create(mem_ctx, stage, options);
+   nir_function *func = nir_function_create(build->shader, "main");
+   build->impl = nir_function_impl_create(func);
+   build->cursor = nir_after_cf_list(&build->impl->body);
+}
+
+static inline void
 nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
 {
    nir_instr_insert(build->cursor, instr);