From 721566bddb2a148e042c4682c35a762fc4e0c3d0 Mon Sep 17 00:00:00 2001 From: Timothy Arceri Date: Thu, 15 Nov 2018 21:28:31 +1100 Subject: [PATCH] nir: rework force_unroll_array_access() Here we rework force_unroll_array_access() so that we can reuse the induction variable detection in a following patch. Reviewed-by: Thomas Helland --- src/compiler/nir/nir_loop_analyze.c | 49 ++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 14 deletions(-) diff --git a/src/compiler/nir/nir_loop_analyze.c b/src/compiler/nir/nir_loop_analyze.c index 700d1fe552b..eef224e4d5b 100644 --- a/src/compiler/nir/nir_loop_analyze.c +++ b/src/compiler/nir/nir_loop_analyze.c @@ -350,6 +350,38 @@ find_loop_terminators(loop_info_state *state) return success; } +/* This function looks for an array access within a loop that uses an + * induction variable for the array index. If found it returns the size of the + * array, otherwise 0 is returned. If we find an induction var we pass it back + * to the caller via array_index_out. + */ +static unsigned +find_array_access_via_induction(loop_info_state *state, + nir_deref_instr *deref, + nir_loop_variable **array_index_out) +{ + for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) { + if (d->deref_type != nir_deref_type_array) + continue; + + assert(d->arr.index.is_ssa); + nir_loop_variable *array_index = get_loop_var(d->arr.index.ssa, state); + + if (array_index->type != basic_induction) + continue; + + if (array_index_out) + *array_index_out = array_index; + + nir_deref_instr *parent = nir_deref_instr_parent(d); + assert(glsl_type_is_array_or_matrix(parent->type)); + + return glsl_get_length(parent->type); + } + + return 0; +} + static int32_t get_iteration(nir_op cond_op, nir_const_value *initial, nir_const_value *step, nir_const_value *limit) @@ -626,20 +658,9 @@ find_trip_count(loop_info_state *state) static bool force_unroll_array_access(loop_info_state *state, nir_deref_instr *deref) { - for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) { - if (d->deref_type != nir_deref_type_array) - continue; - - assert(d->arr.index.is_ssa); - nir_loop_variable *array_index = get_loop_var(d->arr.index.ssa, state); - - if (array_index->type != basic_induction) - continue; - - nir_deref_instr *parent = nir_deref_instr_parent(d); - assert(glsl_type_is_array(parent->type) || - glsl_type_is_matrix(parent->type)); - if (glsl_get_length(parent->type) == state->loop->info->max_trip_count) + unsigned array_size = find_array_access_via_induction(state, deref, NULL); + if (array_size) { + if (array_size == state->loop->info->max_trip_count) return true; if (deref->mode & state->indirect_mask) -- 2.30.2