spirv-opt poor performance (size reduction)

[atgoo]

All-options-on size reduction spirv-opt --inline-entry-points-exhaustive --convert-local-access-chains --eliminate-local-single-block --eliminate-local-single-store --eliminate-insert-extract --eliminate-dead-code-aggressive --eliminate-dead-branches --merge-blocks --eliminate-local-single-block --eliminate-local-single-store --eliminate-local-multi-store --eliminate-insert-extract --eliminate-dead-code-aggressive --eliminate-common-uniform

has very poor performance on these files https://github.com/aras-p/smol-v/blob/master/tests/spirv-dumps/shadertoy

[dneto0]

The problem is running time. Cc @greg-lunarg

[atgoo]

Likely culprit --eliminate-dead-code-aggressive.