From 42ddfc611f84297abeadf74be424387b127f7567 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Tue, 29 Dec 2015 15:25:43 -0800 Subject: [PATCH] nir/dominance: Handle unreachable blocks Previously, nir_dominance.c didn't properly handle unreachable blocks. This can happen if, for instance, you have something like this: loop { if (...) { break; } else { break; } } In this case, the block right after the if statement will be unreachable. This commit makes two changes to handle this. First, it removes an assert and allows block->imm_dom to be null if the block is unreachable. Second, it properly skips unreachable blocks in calc_dom_frontier_cb. Reviewed-by: Jordan Justen Reviewed-by: Connor Abbott --- src/compiler/nir/nir_dominance.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/compiler/nir/nir_dominance.c b/src/compiler/nir/nir_dominance.c index b345b85e8a0..d95f3968074 100644 --- a/src/compiler/nir/nir_dominance.c +++ b/src/compiler/nir/nir_dominance.c @@ -94,7 +94,6 @@ calc_dominance_cb(nir_block *block, void *_state) } } - assert(new_idom); if (block->imm_dom != new_idom) { block->imm_dom = new_idom; state->progress = true; @@ -112,6 +111,11 @@ calc_dom_frontier_cb(nir_block *block, void *state) struct set_entry *entry; set_foreach(block->predecessors, entry) { nir_block *runner = (nir_block *) entry->key; + + /* Skip unreachable predecessors */ + if (runner->imm_dom == NULL) + continue; + while (runner != block->imm_dom) { _mesa_set_add(runner->dom_frontier, block); runner = runner->imm_dom; -- 2.30.2