nv50: insert MOVs also for PHI sources from dominating block

Otherwise we get live range conflicts for operands that are written
only in e.g. an ELSE block but not the IF block.

1 files changed, 25 insertions, 28 deletions

diff --git a/src/gallium/drivers/nv50/nv50_pc_regalloc.c b/src/gallium/drivers/nv50/nv50_pc_regalloc.c
index 3cec219d1a..568384fd82 100644
--- a/src/gallium/drivers/nv50/nv50_pc_regalloc.c
+++ b/src/gallium/drivers/nv50/nv50_pc_regalloc.c
@@ -56,6 +56,25 @@ struct nv_pc_pass {
    uint pass_seq;
 };
 
+/* check if bf (future) can be reached from bp (past) */
+static boolean
+bb_reachable_by(struct nv_basic_block *bf, struct nv_basic_block *bp,
+                struct nv_basic_block *bt)
+{
+   if (bf == bp)
+      return TRUE;
+   if (bp == bt)
+      return FALSE;
+
+   if (bp->out[0] && bp->out[0] != bp &&
+       bb_reachable_by(bf, bp->out[0], bt))
+      return TRUE;
+   if (bp->out[1] && bp->out[1] != bp &&
+       bb_reachable_by(bf, bp->out[1], bt))
+      return TRUE;
+   return FALSE;
+}
+
 static void
 ranges_coalesce(struct nv_range *range)
 {
@@ -422,7 +441,7 @@ pass_generate_phi_movs(struct nv_pc_pass *ctx, struct nv_basic_block *b)
             if (!i->src[j])
                j = 3;
             else
-            if (i->src[j]->value->insn->bb == p)
+            if (bb_reachable_by(pn, i->src[j]->value->insn->bb, b))
                break;
          }
          if (j >= 4)
@@ -580,25 +599,6 @@ live_set_test(struct nv_basic_block *b, struct nv_ref *ref)
    return b->live_set[n / 32] & (1 << (n % 32));
 }
 
-/* check if bf (future) can be reached from bp (past) */
-static boolean
-bb_reachable_by(struct nv_basic_block *bf, struct nv_basic_block *bp,
-		struct nv_basic_block *bt)
-{
-   if (bf == bp)
-      return TRUE;
-   if (bp == bt)
-      return FALSE;
-
-   if (bp->out[0] && bp->out[0] != bp &&
-       bb_reachable_by(bf, bp->out[0], bt))
-      return TRUE;
-   if (bp->out[1] && bp->out[1] != bp &&
-       bb_reachable_by(bf, bp->out[1], bt))
-      return TRUE;
-   return FALSE;
-}
-
 /* The live set of a block contains those values that are live immediately
  * before the beginning of the block.
  */
@@ -918,12 +918,6 @@ pass_linear_scan(struct nv_pc_pass *ctx, int iter)
    return 0;
 }
 
-static int
-pass_eliminate_moves(struct nv_pc_pass *ctx)
-{
-   return 0;
-}
-
 int
 nv_pc_exec_pass1(struct nv_pc *pc)
 {
@@ -971,6 +965,11 @@ nv_pc_exec_pass1(struct nv_pc *pc)
       goto out;
    }
 
+#ifdef NV50_RA_DEBUG_LIVEI
+   for (i = 0; i < pc->num_values; ++i)
+      livei_print(&pc->values[i]);
+#endif
+
    for (i = 0; i < 2; ++i) {
       ret = pass_join_values(ctx, i);
       if (ret)
@@ -981,8 +980,6 @@ nv_pc_exec_pass1(struct nv_pc *pc)
    }
    assert(!ret && "joining");
 
-   ret = pass_eliminate_moves(ctx);
-
    for (i = 0; i < pc->num_values; ++i)
       livei_release(&pc->values[i]);