nir: Convert the builder to use the new NIR cursor API.

The NIR cursor API is exactly what we want for the builder's insertion
point.  This simplifies the API, the implementation, and is actually
more flexible as well.

This required a bit of reworking of TGSI->NIR's if/loop stack handling;
we now store cursors instead of cf_node_lists, for better or worse.

v2: Actually move the cursor in the after_instr case.
v3: Take advantage of nir_instr_insert (suggested by Connor).
v4: vc4 build fixes (thanks to Eric).

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Eric Anholt <[email protected]> [v1]
Reviewed-by: Jason Ekstrand <[email protected]> [v4]
Acked-by: Connor Abbott <[email protected]> [v4]

6 files changed, 15 insertions, 38 deletions

diff --git a/src/glsl/nir/nir_builder.h b/src/glsl/nir/nir_builder.h
index 9223e838095..08b40f8ea7c 100644
--- a/src/glsl/nir/nir_builder.h
+++ b/src/glsl/nir/nir_builder.h
@@ -24,12 +24,12 @@
 #ifndef NIR_BUILDER_H
 #define NIR_BUILDER_H
 
+#include "nir_control_flow.h"
+
 struct exec_list;
 
 typedef struct nir_builder {
-   struct exec_list *cf_node_list;
-   nir_instr *before_instr;
-   nir_instr *after_instr;
+   nir_cursor cursor;
 
    nir_shader *shader;
    nir_function_impl *impl;
@@ -44,42 +44,19 @@ nir_builder_init(nir_builder *build, nir_function_impl *impl)
 }
 
 static inline void
-nir_builder_insert_after_cf_list(nir_builder *build,
-                                 struct exec_list *cf_node_list)
+nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
 {
-   build->cf_node_list = cf_node_list;
-   build->before_instr = NULL;
-   build->after_instr = NULL;
-}
+   nir_instr_insert(build->cursor, instr);
 
-static inline void
-nir_builder_insert_before_instr(nir_builder *build, nir_instr *before_instr)
-{
-   build->cf_node_list = NULL;
-   build->before_instr = before_instr;
-   build->after_instr = NULL;
+   /* Move the cursor forward. */
+   if (build->cursor.option == nir_cursor_after_instr)
+      build->cursor.instr = instr;
 }
 
 static inline void
-nir_builder_insert_after_instr(nir_builder *build, nir_instr *after_instr)
+nir_builder_cf_insert(nir_builder *build, nir_cf_node *cf)
 {
-   build->cf_node_list = NULL;
-   build->before_instr = NULL;
-   build->after_instr = after_instr;
-}
-
-static inline void
-nir_builder_instr_insert(nir_builder *build, nir_instr *instr)
-{
-   if (build->cf_node_list) {
-      nir_instr_insert_after_cf_list(build->cf_node_list, instr);
-   } else if (build->before_instr) {
-      nir_instr_insert_before(build->before_instr, instr);
-   } else {
-      assert(build->after_instr);
-      nir_instr_insert_after(build->after_instr, instr);
-      build->after_instr = instr;
-   }
+   nir_cf_node_insert(build->cursor, cf);
 }
 
 static inline nir_ssa_def *
diff --git a/src/glsl/nir/nir_lower_idiv.c b/src/glsl/nir/nir_lower_idiv.c
index 7b680320783..0e1653dd274 100644
--- a/src/glsl/nir/nir_lower_idiv.c
+++ b/src/glsl/nir/nir_lower_idiv.c
@@ -50,7 +50,7 @@ convert_instr(nir_builder *bld, nir_alu_instr *alu)
 
    is_signed = (op == nir_op_idiv);
 
-   nir_builder_insert_before_instr(bld, &alu->instr);
+   bld->cursor = nir_before_instr(&alu->instr);
 
    numer = nir_ssa_for_src(bld, alu->src[0].src,
                            nir_ssa_alu_instr_src_components(alu, 0));
diff --git a/src/glsl/nir/nir_lower_io.c b/src/glsl/nir/nir_lower_io.c
index c9697e7845e..afb463040cc 100644
--- a/src/glsl/nir/nir_lower_io.c
+++ b/src/glsl/nir/nir_lower_io.c
@@ -84,7 +84,7 @@ get_io_offset(nir_deref_var *deref, nir_instr *instr, nir_src *indirect,
    unsigned base_offset = 0;
 
    nir_builder *b = &state->builder;
-   nir_builder_insert_before_instr(b, instr);
+   b->cursor = nir_before_instr(instr);
 
    nir_deref *tail = &deref->deref;
    while (tail->child != NULL) {
diff --git a/src/glsl/nir/nir_lower_load_const_to_scalar.c b/src/glsl/nir/nir_lower_load_const_to_scalar.c
index a90e5245898..b83ef052ea9 100644
--- a/src/glsl/nir/nir_lower_load_const_to_scalar.c
+++ b/src/glsl/nir/nir_lower_load_const_to_scalar.c
@@ -43,7 +43,7 @@ lower_load_const_instr_scalar(nir_load_const_instr *lower)
 
    nir_builder b;
    nir_builder_init(&b, nir_cf_node_get_function(&lower->instr.block->cf_node));
-   nir_builder_insert_before_instr(&b, &lower->instr);
+   b.cursor = nir_before_instr(&lower->instr);
 
    /* Emit the individual loads. */
    nir_ssa_def *loads[4];
diff --git a/src/glsl/nir/nir_lower_tex_projector.c b/src/glsl/nir/nir_lower_tex_projector.c
index 357131cd728..8a482b182a9 100644
--- a/src/glsl/nir/nir_lower_tex_projector.c
+++ b/src/glsl/nir/nir_lower_tex_projector.c
@@ -46,7 +46,7 @@ nir_lower_tex_projector_block(nir_block *block, void *void_state)
          continue;
 
       nir_tex_instr *tex = nir_instr_as_tex(instr);
-      nir_builder_insert_before_instr(b, &tex->instr);
+      b->cursor = nir_before_instr(&tex->instr);
 
       /* Find the projector in the srcs list, if present. */
       int proj_index;
diff --git a/src/glsl/nir/nir_normalize_cubemap_coords.c b/src/glsl/nir/nir_normalize_cubemap_coords.c
index 0da8447aca1..75b647f96cb 100644
--- a/src/glsl/nir/nir_normalize_cubemap_coords.c
+++ b/src/glsl/nir/nir_normalize_cubemap_coords.c
@@ -52,7 +52,7 @@ normalize_cubemap_coords_block(nir_block *block, void *void_state)
       if (tex->sampler_dim != GLSL_SAMPLER_DIM_CUBE)
          continue;
 
-      nir_builder_insert_before_instr(b, &tex->instr);
+      b->cursor = nir_before_instr(&tex->instr);
 
       for (unsigned i = 0; i < tex->num_srcs; i++) {
          if (tex->src[i].src_type != nir_tex_src_coord)