From 0ddc911f4d83a3c698ea02696e1b8706b2cce381 Mon Sep 17 00:00:00 2001 From: Caio Marcelo de Oliveira Filho Date: Fri, 14 Dec 2018 22:19:24 -0800 Subject: [PATCH] nir: properly clear the entry sources in copy_prop_vars When updating a copy entry source value from a "non-SSA" (the data come from a copy instruction) to a "SSA" (the data or parts of it come from SSA values), it was possible to hold invalid data in ssa[0] depending on the writemask. Because the union, ssa[0] could contain a pointer to a nir_deref_instr left-over from previous non-SSA usage. Change code to clean up the array before use to avoid invalid data around. Fixes: 62332d139c8 "nir: Add a local variable-based copy propagation pass" Reviewed-by: Jason Ekstrand --- src/compiler/nir/nir_opt_copy_prop_vars.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/compiler/nir/nir_opt_copy_prop_vars.c b/src/compiler/nir/nir_opt_copy_prop_vars.c index a540e01529c..ce106be8de3 100644 --- a/src/compiler/nir/nir_opt_copy_prop_vars.c +++ b/src/compiler/nir/nir_opt_copy_prop_vars.c @@ -348,6 +348,9 @@ store_to_entry(struct copy_prop_var_state *state, struct copy_entry *entry, const struct value *value, unsigned write_mask) { if (value->is_ssa) { + /* Clear src if it was being used as non-SSA. */ + if (!entry->src.is_ssa) + memset(entry->src.ssa, 0, sizeof(entry->src.ssa)); entry->src.is_ssa = true; /* Only overwrite the written components */ for (unsigned i = 0; i < 4; i++) { -- 2.30.2