Very slow 80 minutes release build, due mir_pass_scalar_replacement_of_aggregates (sroa) optimization enabled #121354
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Description
When compiling recently project with release flag - cargo build --release I found that compilation takes more than 80 minutes. Debug build completes in ~8 minutes which is acceptable for me.
Cargo timing results:
debug - debug_cargo-timing-20240220T105545Z.html.zip
release - release_cargo-timing-20240220T110513Z.html.zip
Later I run RUSTFLAGS="-Zself-profile" cargo +nightly rustc --release and I got this results
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| Item | Self time | % of total time | Time | Item count |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| mir_pass_scalar_replacement_of_aggregates | 4933.25s | 96.338 | 4933.25s | 4860 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| LLVM_module_optimize | 35.17s | 0.687 | 35.17s | 17 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| LLVM_passes | 34.53s | 0.674 | 34.58s | 1 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| LLVM_lto_optimize | 34.15s | 0.667 | 34.15s | 16 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| finish_ongoing_codegen | 30.40s | 0.594 | 30.40s | 1 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| LLVM_module_codegen_emit_obj | 28.04s | 0.548 | 28.04s | 17 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| typeck | 3.45s | 0.067 | 3.60s | 5318 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| codegen_crate | 2.25s | 0.044 | 4942.10s | 1 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
| LLVM_thin_lto_import | 2.05s | 0.040 | 2.05s | 16 |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+
this is output from RUSTFLAGS="-Zself-profile" cargo +nightly rustc
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| Item | Self time | % of total time | Time | Item count | Incremental result hashing time |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| LLVM_module_codegen_emit_obj | 28.48s | 32.021 | 28.48s | 257 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| run_linker | 19.26s | 21.659 | 19.26s | 1 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| LLVM_passes | 9.83s | 11.050 | 9.83s | 1 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| typeck | 6.91s | 7.765 | 7.28s | 5318 | 2.89s |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| codegen_module | 6.39s | 7.183 | 10.44s | 256 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| mir_borrowck | 1.76s | 1.979 | 3.30s | 5318 | 1.93ms |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| LLVM_module_codegen | 1.37s | 1.544 | 29.85s | 257 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| incr_comp_encode_dep_graph | 1.36s | 1.525 | 1.36s | 1156568 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| metadata_decode_entry_associated_item | 1.00s | 1.130 | 1.00s | 5643 | 0.00ns |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
| eval_to_allocation_raw | 925.25ms | 1.040 | 1.24s | 16774 | 10.06ms |
+-------------------------------------------------------------------------+-----------+-----------------+----------+------------+---------------------------------+
During compilation, Slint generates single rust file with 90000 lines - main_window.rs.zip
repo - https://github.com/qarmin/czkawka/tree/7.0.0/krokiet
git clone https://github.com/qarmin/czkawka.git
cd czkawka/krokiet
time cargo build
time cargo build --release
Meta
rustc --version --verbose:
rustc 1.76.0 (07dca489a 2024-02-04)
binary: rustc
commit-hash: 07dca489ac2d933c78d3c5158e3f43beefeb02ce
commit-date: 2024-02-04
host: x86_64-unknown-linux-gnu
release: 1.76.0
LLVM version: 17.0.6
System:
Host: rafal-komputer Kernel: 6.5.0-15-generic arch: x86_64 bits: 64
Desktop: GNOME v: 45.2 Distro: Ubuntu 23.10 (Mantic Minotaur)
CPU:
Info: quad core model: Intel Core i7-4770 bits: 64 type: MT MCP cache:
L2: 1024 KiB
Speed (MHz): avg: 3691 min/max: 800/3900 cores: 1: 3691 2: 3691 3: 3691
4: 3691 5: 3691 6: 3691 7: 3691 8: 3691