From 7a19e05e8c84152af3a15868f5ef781142ac8e23 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Wed, 10 Jul 2019 15:14:42 -0500 Subject: [PATCH] nir/opt_if: Clean up single-src phis in opt_if_loop_terminator Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111071 Fixes: 2a74296f24ba "nir: add opt_if_loop_terminator()" Reviewed-by: Timothy Arceri --- src/compiler/nir/nir.h | 1 + src/compiler/nir/nir_opt_if.c | 7 +++++++ src/compiler/nir/nir_opt_remove_phis.c | 8 ++++++++ 3 files changed, 16 insertions(+) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index bc7ae1cc03e..2719087e9a4 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -3882,6 +3882,7 @@ bool nir_opt_peephole_select(nir_shader *shader, unsigned limit, bool nir_opt_rematerialize_compares(nir_shader *shader); bool nir_opt_remove_phis(nir_shader *shader); +bool nir_opt_remove_phis_block(nir_block *block); bool nir_opt_shrink_load(nir_shader *shader); diff --git a/src/compiler/nir/nir_opt_if.c b/src/compiler/nir/nir_opt_if.c index 6d488bd76a3..e360c274bc9 100644 --- a/src/compiler/nir/nir_opt_if.c +++ b/src/compiler/nir/nir_opt_if.c @@ -1039,6 +1039,13 @@ opt_if_loop_terminator(nir_if *nif) if (!nir_is_trivial_loop_if(nif, break_blk)) return false; + /* Even though this if statement has a jump on one side, we may still have + * phis afterwards. Single-source phis can be produced by loop unrolling + * or dead control-flow passes and are perfectly legal. Run a quick phi + * removal on the block after the if to clean up any such phis. + */ + nir_opt_remove_phis_block(nir_cf_node_as_block(nir_cf_node_next(&nif->cf_node))); + /* Finally, move the continue from branch after the if-statement. */ nir_cf_list tmp; nir_cf_extract(&tmp, nir_before_block(first_continue_from_blk), diff --git a/src/compiler/nir/nir_opt_remove_phis.c b/src/compiler/nir/nir_opt_remove_phis.c index dd557396ec1..a3186116798 100644 --- a/src/compiler/nir/nir_opt_remove_phis.c +++ b/src/compiler/nir/nir_opt_remove_phis.c @@ -137,6 +137,14 @@ remove_phis_block(nir_block *block, nir_builder *b) return progress; } +bool +nir_opt_remove_phis_block(nir_block *block) +{ + nir_builder b; + nir_builder_init(&b, nir_cf_node_get_function(&block->cf_node)); + return remove_phis_block(block, &b); +} + static bool nir_opt_remove_phis_impl(nir_function_impl *impl) { -- 2.30.2