Mesa (master): nvc0: preemptively insert branch at ENDIF

[Christoph Bumiller]

Module: Mesa
Branch: master
Commit: cd47f10c901d7ac48843586432c2e592ed35eed3
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=cd47f10c901d7ac48843586432c2e592ed35eed3

Author: Christoph Bumiller <e0425955 at student.tuwien.ac.at>
Date:   Thu Feb 24 17:22:15 2011 +0100

nvc0: preemptively insert branch at ENDIF

Might be necessary if a block sneaks in somewhere, like a common
block for moves of phi sources after a loop break.

This is harmless and normally will be removed before emission.

---

 src/gallium/drivers/nvc0/nvc0_pc_optimize.c |    6 +++++-
 src/gallium/drivers/nvc0/nvc0_tgsi_to_nc.c  |    4 ++++
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/src/gallium/drivers/nvc0/nvc0_pc_optimize.c b/src/gallium/drivers/nvc0/nvc0_pc_optimize.c
index 3d03400..8d4d0f3 100644
--- a/src/gallium/drivers/nvc0/nvc0_pc_optimize.c
+++ b/src/gallium/drivers/nvc0/nvc0_pc_optimize.c
@@ -142,9 +142,10 @@ nv_pc_pass_pre_emission(void *priv, struct nv_basic_block *b)
    struct nv_instruction *nvi, *next;
    int j;
 
+   /* find first non-empty block emitted before b */
    for (j = pc->num_blocks - 1; j >= 0 && !pc->bb_list[j]->emit_size; --j);
 
-   if (j >= 0) {
+   for (; j >= 0; --j) {
       in = pc->bb_list[j];
 
       /* check for no-op branches (BRA $PC+8) */
@@ -158,6 +159,9 @@ nv_pc_pass_pre_emission(void *priv, struct nv_basic_block *b)
          nvc0_insn_delete(in->exit);
       }
       b->emit_pos = in->emit_pos + in->emit_size;
+
+      if (in->emit_size) /* no more no-op branches to b */
+         break;
    }
 
    pc->bb_list[pc->num_blocks++] = b;
diff --git a/src/gallium/drivers/nvc0/nvc0_tgsi_to_nc.c b/src/gallium/drivers/nvc0/nvc0_tgsi_to_nc.c
index 5e208e8..fc19ef1 100644
--- a/src/gallium/drivers/nvc0/nvc0_tgsi_to_nc.c
+++ b/src/gallium/drivers/nvc0/nvc0_tgsi_to_nc.c
@@ -1634,6 +1634,10 @@ bld_instruction(struct bld_context *bld,
    {
       struct nv_basic_block *b = new_basic_block(bld->pc);
 
+      if (bld->pc->current_block->exit &&
+          !bld->pc->current_block->exit->terminator)
+         bld_flow(bld, NV_OP_BRA, NULL, NV_CC_P, b, FALSE);
+
       --bld->cond_lvl;
       nvc0_bblock_attach(bld->pc->current_block, b, bld->out_kind);
       nvc0_bblock_attach(bld->cond_bb[bld->cond_lvl], b, CFG_EDGE_FORWARD);