From ec1b96fdc8bccaf2c1a4e1e3cca32b4aacbe4f7c Mon Sep 17 00:00:00 2001 From: Arcady Goldmints-Orlov Date: Thu, 16 Apr 2020 16:28:12 -0500 Subject: [PATCH] nir: Lower returns correctly inside nested loops Inside nested flow control, nir_lower_returns inserts predicated breaks in the outer block. However, it would omit doing this if the remainder of the outer block (after the inner block) was empty. This is not correct in the case of loops, as execution just wraps back around to the start of the loop, so this change doesn't skip the predication inside loops. Fixes: 79dec93ead6e (nir: Add return lowering pass) Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/2724 Reviewed-by: Jason Ekstrand Part-of: --- src/compiler/nir/nir_lower_returns.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/compiler/nir/nir_lower_returns.c b/src/compiler/nir/nir_lower_returns.c index e166a7cc32a..ecbbf43da3b 100644 --- a/src/compiler/nir/nir_lower_returns.c +++ b/src/compiler/nir/nir_lower_returns.c @@ -50,7 +50,7 @@ predicate_following(nir_cf_node *node, struct lower_returns_state *state) nir_builder *b = &state->builder; b->cursor = nir_after_cf_node_and_phis(node); - if (nir_cursors_equal(b->cursor, nir_after_cf_list(state->cf_list))) + if (!state->loop && nir_cursors_equal(b->cursor, nir_after_cf_list(state->cf_list))) return; /* Nothing to predicate */ assert(state->return_flag); -- 2.30.2