From 7fe3731e9fa884d1b449af3dd8706aec3970ef77 Mon Sep 17 00:00:00 2001 From: Timothy Arceri Date: Mon, 26 Mar 2018 10:31:26 +1100 Subject: glsl: fix infinite loop caused by bug in loop unrolling pass Just checking for 2 jumps is not enough to be sure we can do a complex loop unroll. We need to make sure we also have also found 2 loop terminators. Without this we were attempting to unroll a loop where the second jump was nested inside multiple ifs which loop analysis is unable to detect as a terminator. We ended up splicing out the first terminator but failed to actually unroll the loop, this resulted in the creation of a possible infinite loop. Fixes: 646621c66da9 "glsl: make loop unrolling more like the nir unrolling path" Tested-by: Gert Wollny Reviewed-by: Ian Romanick Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105670 (cherry picked from commit 56b867395dee1a48594b27987d3bf68a4e745dda) Squashed with: glsl: remove unreachable assert() Earlier commit enforced that we'll bail out if the number of terminators is different than 2. With that in mind, the assert() will never trigger. Fixes: 56b867395de ("glsl: fix infinite loop caused by bug in loop unrolling pass") Reviewed-by: Timothy Arceri Signed-off-by: Emil Velikov (cherry picked from commit 8eceac9de7d3cd4fddabbe61d512acfed9812169) --- src/compiler/glsl/loop_unroll.cpp | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'src/compiler') diff --git a/src/compiler/glsl/loop_unroll.cpp b/src/compiler/glsl/loop_unroll.cpp index 6e06a30fb91..874f4185681 100644 --- a/src/compiler/glsl/loop_unroll.cpp +++ b/src/compiler/glsl/loop_unroll.cpp @@ -519,7 +519,7 @@ loop_unroll_visitor::visit_leave(ir_loop *ir) * isn't any additional unknown terminators, or any other jumps nested * inside futher ifs. */ - if (ls->num_loop_jumps != 2) + if (ls->num_loop_jumps != 2 || ls->terminators.length() != 2) return visit_continue; ir_instruction *first_ir = @@ -528,8 +528,6 @@ loop_unroll_visitor::visit_leave(ir_loop *ir) unsigned term_count = 0; bool first_term_then_continue = false; foreach_in_list(loop_terminator, t, &ls->terminators) { - assert(term_count < 2); - ir_if *ir_if = t->ir->as_if(); assert(ir_if != NULL); -- cgit v1.2.3