<div dir="ltr"><div>Reviewed-by: Connor Abbott <<a href="mailto:cwabbott0@gmail.com">cwabbott0@gmail.com</a>></div><div> </div><div>I agree that if we ever need to bring this back, we should just check for both branches empty and no phis afterwards. </div></div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Feb 14, 2019 at 2:38 AM Timothy Arceri <<a href="mailto:tarceri@itsqueeze.com">tarceri@itsqueeze.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">This was probably useful when it was first written, however it looks to be no longer necessary. As far as I can tell these days dce is smart enough to remove useless instructions from if branches. Once this is done nir_opt_peephole_select() will end up removing the empty if. Removing this support reduces the dolphin uber shader compilation time by around 60%. Compile time is reduced due to no longer having to compute the live ssa defs metadata so much. No shader-db changes on i965 or radeonsi. --- src/compiler/nir/nir_opt_dead_cf.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/src/compiler/nir/nir_opt_dead_cf.c b/src/compiler/nir/nir_opt_dead_cf.c index 14986732096..053c5743527 100644 --- a/src/compiler/nir/nir_opt_dead_cf.c +++ b/src/compiler/nir/nir_opt_dead_cf.c @@ -180,7 +180,7 @@ def_not_live_out(nir_ssa_def *def, void *state) } /* - * Test if a loop node or if node is dead. Such nodes are dead if: + * Test if a loop node is dead. Such nodes are dead if: * * 1) It has no side effects (i.e. intrinsics which could possibly affect the * state of the program aside from producing an SSA value, indicated by a lack @@ -198,7 +198,7 @@ def_not_live_out(nir_ssa_def *def, void *state) static bool node_is_dead(nir_cf_node *node) { - assert(node->type == nir_cf_node_loop || node->type == nir_cf_node_if); + assert(node->type == nir_cf_node_loop); nir_block *before = nir_cf_node_as_block(nir_cf_node_prev(node)); nir_block *after = nir_cf_node_as_block(nir_cf_node_next(node)); @@ -230,11 +230,6 @@ dead_cf_block(nir_block *block) { nir_if *following_if = nir_block_get_following_if(block); if (following_if) { - if (node_is_dead(&following_if->cf_node)) { - nir_cf_node_remove(&following_if->cf_node); - return true; - } - if (!nir_src_is_const(following_if->condition)) return false; -- 2.20.1 _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org" target="_blank">mesa-dev@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev" rel="noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/mesa-dev</a></blockquote></div>