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perf: fold identical code when linking the optimized runtime - #2106
Links the optimized runtimes (-Poptimized, -PoptimizedWithInspector) with -Wl,--icf=all, so lld folds identical functions into one copy. No V8 rebuild is needed.
libNativeScript.so, arm64
before
after
optimized (what release apps ship)
27.30 MB
24.46 MB (−2.8 MB, −10%)
optimized-with-inspector
28.33 MB
25.40 MB
optimized, deflated (≈ Play download)
8.87 MiB
8.36 MiB
--icf=safe folds nothing for this build. It only folds functions whose address is known not to be taken, and V8's objects carry no address-significance tables.
With --icf=all, two identical functions can end up at the same address. Code that compares function pointers for identity would break. The full test suite doesn't show any such dependency.
Also checked: uncompressed dex. I looked at whether the app template should store classes.dex uncompressed, so the installed app doesn't keep an extracted copy. For App Bundle installs it's already uncompressed: in the device split APKs generated from a release AAB for an API 33 arm64 phone, classes.dex is stored (base-master). So this PR doesn't change the dex packaging.
Does your commit message include the wording below to reference a specific issue in this repo?
No issue.
Related Pull Requests
None.
Does your pull request have unit tests?
No new tests; this is a link flag.
Device suite: a debug test app on the optimized-with-inspector runtime (the ICF link only applies to optimized builds), API 36 emulator. Results are identical with and without ICF: 1551 specs, 0 failures, 7 skipped, 95 disabled. The intentional native-crash-on-alien-thread from UncaughtErrorPolicyTest appears in both.
Speed:
JNI microbenchmarks (debug.ns.jnibench, optimized release, Galaxy S20 FE, alternating builds): neutral within the phone's clock-state noise. A few rows moved ±3–10% in both directions between runs.
Hardware counters: two builds that differ only in this flag execute the same number of instructions for the same work: about 7.25–7.36 billion for the String-argument callback benchmark and 13.1–13.3 billion for all callback benchmarks. ICF never used more cycles.
Summary by CodeRabbit
Build Improvements
Optimized NativeScript builds now use an additional linker optimization. Non-optimized builds are unchanged.
This update affects how optimized builds are produced; no changes to app features or behavior are noted.
Link the optimized runtimes with -Wl,--icf=all. libNativeScript.so
(arm64) drops from 27.3 MB to 24.5 MB, and the optimized-with-inspector
one from 28.3 MB to 25.4 MB. --icf=safe folds nothing, because the V8
objects have no address-significance tables.
The change adds a linker flag to shrink optimized builds. The author reports a full device test suite with no failures. No concrete merge-blocking risk was found.
Pre-merge checks: 4
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Title check
The title "perf: fold identical code when linking the optimized runtime" matches the main change. The raw summary and objectives show the PR adds -Wl,--icf=all to the linker flags for optimized Native…
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Full details: Title check
Explanation
The title "perf: fold identical code when linking the optimized runtime" matches the main change. The raw summary and objectives show the PR adds -Wl,--icf=all to the linker flags for optimized NativeScript runtime builds, which folds identical functions to reduce library size. The title is specific and concise, and it avoids file lists and vague terms.
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test-app/runtime/CMakeLists.txt
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Description
Links the optimized runtimes (
-Poptimized,-PoptimizedWithInspector) with-Wl,--icf=all, so lld folds identical functions into one copy. No V8 rebuild is needed.libNativeScript.so, arm64--icf=safefolds nothing for this build. It only folds functions whose address is known not to be taken, and V8's objects carry no address-significance tables.With
--icf=all, two identical functions can end up at the same address. Code that compares function pointers for identity would break. The full test suite doesn't show any such dependency.Also checked: uncompressed dex. I looked at whether the app template should store
classes.dexuncompressed, so the installed app doesn't keep an extracted copy. For App Bundle installs it's already uncompressed: in the device split APKs generated from a release AAB for an API 33 arm64 phone,classes.dexis stored (base-master). So this PR doesn't change the dex packaging.Does your commit message include the wording below to reference a specific issue in this repo?
No issue.
Related Pull Requests
None.
Does your pull request have unit tests?
No new tests; this is a link flag.
native-crash-on-alien-threadfromUncaughtErrorPolicyTestappears in both.debug.ns.jnibench, optimized release, Galaxy S20 FE, alternating builds): neutral within the phone's clock-state noise. A few rows moved ±3–10% in both directions between runs.Summary by CodeRabbit