From 4a600024242be2b8684ab2cc215171f31db594b0 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Thu, 3 Mar 2016 09:02:30 +0100 Subject: [PATCH] glsl/opt_array_splitting: Fix crash when doing array indexing into other arrays When we find indirect indexing into an array, the current implementation of the array spliiting optimization pass does not look further into the expression tree. However, if the variable expression involves variable indexing into other arrays, we can miss that these other arrays also have variable indexing. If that happens, the pass will crash later on after hitting an assertion put there to ensure that split arrays are in fact always indexed via constants: shader_runner: opt_array_splitting.cpp:296: void ir_array_splitting_visitor::split_deref(ir_dereference**): Assertion `constant' failed. This patch fixes the problem by letting the pass step into the variable index expression to identify these cases properly. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89607 Reviewed-by: Timothy Arceri --- src/compiler/glsl/opt_array_splitting.cpp | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/src/compiler/glsl/opt_array_splitting.cpp b/src/compiler/glsl/opt_array_splitting.cpp index cceec6b6431..2f6afb080cc 100644 --- a/src/compiler/glsl/opt_array_splitting.cpp +++ b/src/compiler/glsl/opt_array_splitting.cpp @@ -185,8 +185,18 @@ ir_array_reference_visitor::visit_enter(ir_dereference_array *ir) /* If the access to the array has a variable index, we wouldn't * know which split variable this dereference should go to. */ - if (entry && !ir->array_index->as_constant()) - entry->split = false; + if (!ir->array_index->as_constant()) { + if (entry) + entry->split = false; + /* This variable indexing could come from a different array dereference + * that also has variable indexing, that is, something like a[b[a[b[0]]]]. + * If we return visit_continue_with_parent here for the first appearence + * of a, then we can miss that b also has indirect indexing (if this is + * the only place in the program where such indirect indexing into b + * happens), so keep going. + */ + return visit_continue; + } /* If the index is also array dereference, visit index. */ if (ir->array_index->as_dereference_array()) -- 2.30.2