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]

11 files changed, 38 insertions, 61 deletions

diff --git a/src/gallium/auxiliary/nir/tgsi_to_nir.c b/src/gallium/auxiliary/nir/tgsi_to_nir.c
index 278d5e9bf5b..db50734efd5 100644
--- a/src/gallium/auxiliary/nir/tgsi_to_nir.c
+++ b/src/gallium/auxiliary/nir/tgsi_to_nir.c
@@ -65,24 +65,24 @@ struct ttn_compile {
    nir_register *addr_reg;
 
    /**
-    * Stack of cf_node_lists where instructions should be pushed as we pop
+    * Stack of nir_cursors where instructions should be pushed as we pop
     * back out of the control flow stack.
     *
     * For each IF/ELSE/ENDIF block, if_stack[if_stack_pos] has where the else
     * instructions should be placed, and if_stack[if_stack_pos - 1] has where
     * the next instructions outside of the if/then/else block go.
     */
-   struct exec_list **if_stack;
+   nir_cursor *if_stack;
    unsigned if_stack_pos;
 
    /**
-    * Stack of cf_node_lists where instructions should be pushed as we pop
+    * Stack of nir_cursors where instructions should be pushed as we pop
     * back out of the control flow stack.
     *
     * loop_stack[loop_stack_pos - 1] contains the cf_node_list for the outside
     * of the loop.
     */
-   struct exec_list **loop_stack;
+   nir_cursor *loop_stack;
    unsigned loop_stack_pos;
 
    /* How many TGSI_FILE_IMMEDIATE vec4s have been parsed so far. */
@@ -922,7 +922,7 @@ ttn_if(struct ttn_compile *c, nir_ssa_def *src, bool is_uint)
    nir_builder *b = &c->build;
 
    /* Save the outside-of-the-if-statement node list. */
-   c->if_stack[c->if_stack_pos] = b->cf_node_list;
+   c->if_stack[c->if_stack_pos] = b->cursor;
    c->if_stack_pos++;
 
    src = ttn_channel(b, src, X);
@@ -933,11 +933,11 @@ ttn_if(struct ttn_compile *c, nir_ssa_def *src, bool is_uint)
    } else {
       if_stmt->condition = nir_src_for_ssa(nir_fne(b, src, nir_imm_int(b, 0)));
    }
-   nir_cf_node_insert_end(b->cf_node_list, &if_stmt->cf_node);
+   nir_builder_cf_insert(b, &if_stmt->cf_node);
 
-   nir_builder_insert_after_cf_list(b, &if_stmt->then_list);
+   b->cursor = nir_after_cf_list(&if_stmt->then_list);
 
-   c->if_stack[c->if_stack_pos] = &if_stmt->else_list;
+   c->if_stack[c->if_stack_pos] = nir_after_cf_list(&if_stmt->else_list);
    c->if_stack_pos++;
 }
 
@@ -946,7 +946,7 @@ ttn_else(struct ttn_compile *c)
 {
    nir_builder *b = &c->build;
 
-   nir_builder_insert_after_cf_list(b, c->if_stack[c->if_stack_pos - 1]);
+   b->cursor = c->if_stack[c->if_stack_pos - 1];
 }
 
 static void
@@ -955,7 +955,7 @@ ttn_endif(struct ttn_compile *c)
    nir_builder *b = &c->build;
 
    c->if_stack_pos -= 2;
-   nir_builder_insert_after_cf_list(b, c->if_stack[c->if_stack_pos]);
+   b->cursor = c->if_stack[c->if_stack_pos];
 }
 
 static void
@@ -964,13 +964,13 @@ ttn_bgnloop(struct ttn_compile *c)
    nir_builder *b = &c->build;
 
    /* Save the outside-of-the-loop node list. */
-   c->loop_stack[c->loop_stack_pos] = b->cf_node_list;
+   c->loop_stack[c->loop_stack_pos] = b->cursor;
    c->loop_stack_pos++;
 
    nir_loop *loop = nir_loop_create(b->shader);
-   nir_cf_node_insert_end(b->cf_node_list, &loop->cf_node);
+   nir_builder_cf_insert(b, &loop->cf_node);
 
-   nir_builder_insert_after_cf_list(b, &loop->body);
+   b->cursor = nir_after_cf_list(&loop->body);
 }
 
 static void
@@ -993,7 +993,7 @@ ttn_endloop(struct ttn_compile *c)
    nir_builder *b = &c->build;
 
    c->loop_stack_pos--;
-   nir_builder_insert_after_cf_list(b, c->loop_stack[c->loop_stack_pos]);
+   b->cursor = c->loop_stack[c->loop_stack_pos];
 }
 
 static void
@@ -1803,7 +1803,7 @@ tgsi_to_nir(const void *tgsi_tokens,
    nir_function_impl *impl = nir_function_impl_create(overload);
 
    nir_builder_init(&c->build, impl);
-   nir_builder_insert_after_cf_list(&c->build, &impl->body);
+   c->build.cursor = nir_after_cf_list(&impl->body);
 
    s->num_inputs = scan.file_max[TGSI_FILE_INPUT] + 1;
    s->num_uniforms = scan.const_file_max[0] + 1;
@@ -1819,10 +1819,10 @@ tgsi_to_nir(const void *tgsi_tokens,
    c->num_samp_types = scan.file_max[TGSI_FILE_SAMPLER_VIEW] + 1;
    c->samp_types = rzalloc_array(c, nir_alu_type, c->num_samp_types);
 
-   c->if_stack = rzalloc_array(c, struct exec_list *,
+   c->if_stack = rzalloc_array(c, nir_cursor,
                                (scan.opcode_count[TGSI_OPCODE_IF] +
                                 scan.opcode_count[TGSI_OPCODE_UIF]) * 2);
-   c->loop_stack = rzalloc_array(c, struct exec_list *,
+   c->loop_stack = rzalloc_array(c, nir_cursor,
                                  scan.opcode_count[TGSI_OPCODE_BGNLOOP]);
 
    ret = tgsi_parse_init(&parser, tgsi_tokens);
diff --git a/src/gallium/drivers/freedreno/ir3/ir3_nir_lower_if_else.c b/src/gallium/drivers/freedreno/ir3/ir3_nir_lower_if_else.c
index bed7b7b826a..d57eb2ba713 100644
--- a/src/gallium/drivers/freedreno/ir3/ir3_nir_lower_if_else.c
+++ b/src/gallium/drivers/freedreno/ir3/ir3_nir_lower_if_else.c
@@ -172,7 +172,7 @@ flatten_block(nir_builder *bld, nir_block *if_block, nir_block *prev_block,
 					(intr->intrinsic == nir_intrinsic_discard_if)) {
 				nir_ssa_def *discard_cond;
 
-				nir_builder_insert_after_instr(bld,
+				bld->cursor = nir_after_instr(
 						nir_block_last_instr(prev_block));
 
 				if (invert) {
diff --git a/src/gallium/drivers/vc4/vc4_nir_lower_blend.c b/src/gallium/drivers/vc4/vc4_nir_lower_blend.c
index a372a6c0cdc..808cbea8fde 100644
--- a/src/gallium/drivers/vc4/vc4_nir_lower_blend.c
+++ b/src/gallium/drivers/vc4/vc4_nir_lower_blend.c
@@ -409,7 +409,7 @@ vc4_nir_lower_blend_block(nir_block *block, void *state)
                         nir_cf_node_get_function(&block->cf_node);
                 nir_builder b;
                 nir_builder_init(&b, impl);
-                nir_builder_insert_before_instr(&b, &intr->instr);
+                b.cursor = nir_before_instr(&intr->instr);
                 vc4_nir_lower_blend_instr(c, &b, intr);
         }
         return true;
diff --git a/src/gallium/drivers/vc4/vc4_nir_lower_io.c b/src/gallium/drivers/vc4/vc4_nir_lower_io.c
index 229d41147d8..b632370cbb2 100644
--- a/src/gallium/drivers/vc4/vc4_nir_lower_io.c
+++ b/src/gallium/drivers/vc4/vc4_nir_lower_io.c
@@ -56,7 +56,7 @@ static void
 vc4_nir_lower_input(struct vc4_compile *c, nir_builder *b,
                     nir_intrinsic_instr *intr)
 {
-        nir_builder_insert_before_instr(b, &intr->instr);
+        b->cursor = nir_before_instr(&intr->instr);
 
         if (c->stage == QSTAGE_FRAG && intr->const_index[0] ==
             VC4_NIR_TLB_COLOR_READ_INPUT) {
@@ -160,7 +160,7 @@ vc4_nir_lower_output(struct vc4_compile *c, nir_builder *b,
         /* All TGSI-to-NIR outputs are VEC4. */
         assert(intr->num_components == 4);
 
-        nir_builder_insert_before_instr(b, &intr->instr);
+        b->cursor = nir_before_instr(&intr->instr);
 
         for (unsigned i = 0; i < intr->num_components; i++) {
                 nir_intrinsic_instr *intr_comp =
@@ -189,7 +189,7 @@ vc4_nir_lower_uniform(struct vc4_compile *c, nir_builder *b,
                 return;
         assert(intr->num_components == 4);
 
-        nir_builder_insert_before_instr(b, &intr->instr);
+        b->cursor = nir_before_instr(&intr->instr);
 
         /* Generate scalar loads equivalent to the original VEC4. */
         nir_ssa_def *dests[4];
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)
diff --git a/src/mesa/program/prog_to_nir.c b/src/mesa/program/prog_to_nir.c
index d96b7bc8782..fccd16fc8c0 100644
--- a/src/mesa/program/prog_to_nir.c
+++ b/src/mesa/program/prog_to_nir.c
@@ -1108,7 +1108,7 @@ prog_to_nir(const struct gl_program *prog,
 
    c->build.shader = s;
    c->build.impl = impl;
-   nir_builder_insert_after_cf_list(&c->build, &impl->body);
+   c->build.cursor = nir_after_cf_list(&impl->body);
 
    setup_registers_and_variables(c);
    if (unlikely(c->error))