This patch is based on https://lists.freedesktop.org/archives/mesa-dev/2018-February/185805.html
Dave Airlie: "A bunch of CTS tests led me to write tests/shaders/ssa/fs-while-loop-rotate-value.shader_test which r600/sb always fell over on. GCM seems to move some of the copies into other basic blocks, if we don't allow this to happen then it doesn't seem to schedule them badly. Everything I've read on SSA/phi copies say they have to happen in parallel, so keeping them in the same basic block seems like a good way to keep some of that property." This patch differs from the one proposed by Dave in that it only adds the NF_DONT_MOVE flag to copy_move instructions that are created by split_phi* and that are located in loops. Fixes piglit: tests/shaders/ssa/fs-while-loop-rotate-value.shader_test (no regressions in the shader set). It also fixes all failing tests from dEQP-GLES3.functional.shaders.loops.* Signed-off-by: Gert Wollny <[email protected]> --- src/gallium/drivers/r600/sb/sb_ra_init.cpp | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/gallium/drivers/r600/sb/sb_ra_init.cpp b/src/gallium/drivers/r600/sb/sb_ra_init.cpp index 985e179452..c557b86871 100644 --- a/src/gallium/drivers/r600/sb/sb_ra_init.cpp +++ b/src/gallium/drivers/r600/sb/sb_ra_init.cpp @@ -545,10 +545,13 @@ void ra_split::split_phi_src(container_node *loc, container_node *c, continue; value *t = sh.create_temp_value(); + alu_node* n = sh.create_copy_mov(t, v); + if (loop) + n->flags |= NF_DONT_MOVE; if (loop && id == 0) - loc->insert_before(sh.create_copy_mov(t, v)); + loc->insert_before(n); else - loc->push_back(sh.create_copy_mov(t, v)); + loc->push_back(n); v = t; sh.coal.add_edge(v, d, coalescer::phi_cost); @@ -566,9 +569,10 @@ void ra_split::split_phi_dst(node* loc, container_node *c, bool loop) { value *t = sh.create_temp_value(); node *cp = sh.create_copy_mov(v, t); - if (loop) + if (loop) { + cp->flags |= NF_DONT_MOVE; static_cast<container_node*>(loc)->push_front(cp); - else + } else loc->insert_after(cp); v = t; } -- 2.16.1 _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
