Mesa (staging/20.0): nir/search: Use larger type to hold linearized index

[GitLab Mirror]

Module: Mesa
Branch: staging/20.0
Commit: 760b8cfd1c3afd483eea30383a2cc7593f7640dd
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=760b8cfd1c3afd483eea30383a2cc7593f7640dd

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Tue Feb 18 15:31:37 2020 -0800

nir/search: Use larger type to hold linearized index

"index" is an offset into a linearized 3-dimensional array.  Starting
with fbd5359a0a6, the 3-dimensional array can have 43 elements in each
dimension.  43**3 = 79507, and that will overflow the uint16_t.

See also the discussion in MR !3765.

Fixes: fbd5359a0a6 ("nir/algebraic: Rearrange bcsel sequences generated by nir_opt_peephole_select")
Suggested-by: Connor Abbott <cwabbott0 at gmail.com>
Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3871>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3871>
(cherry picked from commit 58bdc1c748f2922b3970c3b3a41d1b0977f07886)

---

 .pick_status.json             | 2 +-
 src/compiler/nir/nir_search.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index 36c0c588f09..b6e26b8bb63 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -157,7 +157,7 @@
         "description": "nir/search: Use larger type to hold linearized index",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": "fbd5359a0a6f4b6d220c4cea9020ec4665ed4955"
     },
diff --git a/src/compiler/nir/nir_search.c b/src/compiler/nir/nir_search.c
index 458a4eeb1ce..7abb023faf5 100644
--- a/src/compiler/nir/nir_search.c
+++ b/src/compiler/nir/nir_search.c
@@ -789,7 +789,7 @@ nir_algebraic_automaton(nir_instr *instr, struct util_dynarray *states,
        * itertools.product(), which was used to emit the transition
        * table.
        */
-      uint16_t index = 0;
+      unsigned index = 0;
       for (unsigned i = 0; i < nir_op_infos[op].num_inputs; i++) {
          index *= tbl->num_filtered_states;
          index += tbl->filter[*util_dynarray_element(states, uint16_t,