gallivm: fix loops and conditionals within GS

We were using simple temporaries, without using alloca or phi
nodes which meant that on every iteration of the loop our
temporaries, which were holding the number of vertices and
primitives which were emitted, were being reset to zero. Now
we're using alloca to allocate those variables to preserve
them across conditionals.

Signed-off-by: Zack Rusin <[email protected]>
Reviewed-by: Jose Fonseca <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

2 files changed, 105 insertions, 19 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
index 558a8dd7dd8..23ccaccc15e 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
@@ -393,9 +393,9 @@ struct lp_build_tgsi_soa_context
    struct lp_build_context elem_bld;
 
    const struct lp_build_tgsi_gs_iface *gs_iface;
-   LLVMValueRef emitted_prims_vec;
-   LLVMValueRef total_emitted_vertices_vec;
-   LLVMValueRef emitted_vertices_vec;
+   LLVMValueRef emitted_prims_vec_ptr;
+   LLVMValueRef total_emitted_vertices_vec_ptr;
+   LLVMValueRef emitted_vertices_vec_ptr;
    /* if a shader doesn't have ENDPRIM instruction but it has
     * a number of EMIT instructions it means the END instruction
     * implicitly invokes ENDPRIM. handle this via a flag here
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
index 1e062e94e93..6cc72ff948d 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
@@ -1150,7 +1150,7 @@ emit_store_chan(
       }
       else {
          LLVMValueRef out_ptr = lp_get_output_ptr(bld, reg->Register.Index,
-                                               chan_index);
+                                                  chan_index);
          lp_exec_mask_store(&bld->exec_mask, bld_store, pred, value, out_ptr);
       }
       break;
@@ -2213,6 +2213,41 @@ mask_to_one_vec(struct lp_build_tgsi_context *bld_base)
 }
 
 static void
+increment_vec_ptr_by_mask(struct lp_build_tgsi_context * bld_base,
+                          LLVMValueRef ptr,
+                          LLVMValueRef mask)
+{
+   LLVMBuilderRef builder = bld_base->base.gallivm->builder;
+
+   LLVMValueRef current_vec = LLVMBuildLoad(builder, ptr, "");
+   
+   current_vec = LLVMBuildAdd(builder, current_vec, mask, "");
+   
+   LLVMBuildStore(builder, current_vec, ptr);
+}
+
+static void
+clear_uint_vec_ptr_from_mask(struct lp_build_tgsi_context * bld_base,
+                             LLVMValueRef ptr,
+                             LLVMValueRef mask)
+{
+   LLVMBuilderRef builder = bld_base->base.gallivm->builder;
+
+   LLVMValueRef current_vec = LLVMBuildLoad(builder, ptr, "");
+   LLVMValueRef full_mask = lp_build_cmp(&bld_base->uint_bld,
+                                         PIPE_FUNC_NOTEQUAL,
+                                         mask,
+                                         bld_base->uint_bld.zero);
+
+   current_vec = lp_build_select(&bld_base->uint_bld,
+                                 full_mask,
+                                 bld_base->uint_bld.zero,
+                                 current_vec);
+   
+   LLVMBuildStore(builder, current_vec, ptr);
+}
+
+static void
 emit_vertex(
    const struct lp_build_tgsi_action * action,
    struct lp_build_tgsi_context * bld_base,
@@ -2223,14 +2258,22 @@ emit_vertex(
 
    if (bld->gs_iface->emit_vertex) {
       LLVMValueRef masked_ones = mask_to_one_vec(bld_base);
+      LLVMValueRef total_emitted_vertices_vec =
+         LLVMBuildLoad(builder, bld->total_emitted_vertices_vec_ptr, "");
       gather_outputs(bld);
       bld->gs_iface->emit_vertex(bld->gs_iface, &bld->bld_base,
                                  bld->outputs,
-                                 bld->total_emitted_vertices_vec);
-      bld->emitted_vertices_vec =
-         LLVMBuildAdd(builder, bld->emitted_vertices_vec, masked_ones, "");
-      bld->total_emitted_vertices_vec =
-         LLVMBuildAdd(builder, bld->total_emitted_vertices_vec, masked_ones, "");
+                                 total_emitted_vertices_vec);
+      increment_vec_ptr_by_mask(bld_base, bld->emitted_vertices_vec_ptr,
+                                masked_ones);
+      increment_vec_ptr_by_mask(bld_base, bld->total_emitted_vertices_vec_ptr,
+                                masked_ones);
+#if DUMP_GS_EMITS
+      lp_build_print_value(bld->bld_base.base.gallivm, " +++ emit vertex masked ones = ",
+                           masked_ones);
+      lp_build_print_value(bld->bld_base.base.gallivm, " +++ emit vertex emitted = ",
+                           total_emitted_vertices_vec);
+#endif
       bld->pending_end_primitive = TRUE;
    }
 }
@@ -2247,12 +2290,32 @@ end_primitive(
 
    if (bld->gs_iface->end_primitive) {
       LLVMValueRef masked_ones = mask_to_one_vec(bld_base);
+      LLVMValueRef emitted_vertices_vec =
+         LLVMBuildLoad(builder, bld->emitted_vertices_vec_ptr, "");
+      LLVMValueRef emitted_prims_vec =
+         LLVMBuildLoad(builder, bld->emitted_prims_vec_ptr, "");
+      
       bld->gs_iface->end_primitive(bld->gs_iface, &bld->bld_base,
-                                   bld->emitted_vertices_vec,
-                                   bld->emitted_prims_vec);
-      bld->emitted_prims_vec =
-         LLVMBuildAdd(builder, bld->emitted_prims_vec, masked_ones, "");
-      bld->emitted_vertices_vec = bld_base->uint_bld.zero;
+                                   emitted_vertices_vec,
+                                   emitted_prims_vec);
+
+#if DUMP_GS_EMITS
+      lp_build_print_value(bld->bld_base.base.gallivm, " +++ end prim masked ones = ",
+                           masked_ones);
+      lp_build_print_value(bld->bld_base.base.gallivm, " +++ end prim emitted verts1 = ",
+                           emitted_vertices_vec);
+      lp_build_print_value(bld->bld_base.base.gallivm, " +++ end prim emitted prims1 = ",
+                           LLVMBuildLoad(builder, bld->emitted_prims_vec_ptr, ""));
+#endif
+      increment_vec_ptr_by_mask(bld_base, bld->emitted_prims_vec_ptr,
+                                masked_ones);
+      clear_uint_vec_ptr_from_mask(bld_base, bld->emitted_vertices_vec_ptr,
+                                   masked_ones);
+#if DUMP_GS_EMITS
+      lp_build_print_value(bld->bld_base.base.gallivm, " +++ end prim emitted verts2 = ",
+                           LLVMBuildLoad(builder, bld->emitted_vertices_vec_ptr, ""));
+#endif
+
       bld->pending_end_primitive = FALSE;
    }
 }
@@ -2546,15 +2609,32 @@ static void emit_prologue(struct lp_build_tgsi_context * bld_base)
 
    if (bld->gs_iface) {
       struct lp_build_context *uint_bld = &bld->bld_base.uint_bld;
-      bld->emitted_prims_vec = uint_bld->zero;
-      bld->emitted_vertices_vec = uint_bld->zero;
-      bld->total_emitted_vertices_vec = uint_bld->zero;
+      bld->emitted_prims_vec_ptr =
+         lp_build_alloca(gallivm,
+                         uint_bld->vec_type,
+                         "emitted_prims_ptr");
+      bld->emitted_vertices_vec_ptr =
+         lp_build_alloca(gallivm,
+                         uint_bld->vec_type,
+                         "emitted_vertices_ptr");
+      bld->total_emitted_vertices_vec_ptr =
+         lp_build_alloca(gallivm,
+                         uint_bld->vec_type,
+                         "total_emitted_vertices_ptr");
+
+      LLVMBuildStore(gallivm->builder, uint_bld->zero,
+                     bld->emitted_prims_vec_ptr);
+      LLVMBuildStore(gallivm->builder, uint_bld->zero,
+                     bld->emitted_vertices_vec_ptr);
+      LLVMBuildStore(gallivm->builder, uint_bld->zero,
+                     bld->total_emitted_vertices_vec_ptr);
    }
 }
 
 static void emit_epilogue(struct lp_build_tgsi_context * bld_base)
 {
    struct lp_build_tgsi_soa_context * bld = lp_soa_context(bld_base);
+   LLVMBuilderRef builder = bld_base->base.gallivm->builder;
 
    if (0) {
       /* for debugging */
@@ -2564,16 +2644,22 @@ static void emit_epilogue(struct lp_build_tgsi_context * bld_base)
    /* If we have indirect addressing in outputs we need to copy our alloca array
     * to the outputs slots specified by the caller */
    if (bld->gs_iface) {
+      LLVMValueRef total_emitted_vertices_vec;
+      LLVMValueRef emitted_prims_vec;
       /* flush the accumulated vertices as a primitive */
       if (bld->pending_end_primitive) {
          end_primitive(NULL, bld_base, NULL);
          bld->pending_end_primitive = FALSE;
       }
+      total_emitted_vertices_vec =
+         LLVMBuildLoad(builder, bld->total_emitted_vertices_vec_ptr, "");
+      emitted_prims_vec =
+         LLVMBuildLoad(builder, bld->emitted_prims_vec_ptr, "");
 
       bld->gs_iface->gs_epilogue(bld->gs_iface,
                                  &bld->bld_base,
-                                 bld->total_emitted_vertices_vec,
-                                 bld->emitted_prims_vec);
+                                 total_emitted_vertices_vec,
+                                 emitted_prims_vec);
    } else {
       gather_outputs(bld);
    }