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build+perf: wasm-opt the shipped wasm, and measure real frames in CI

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emcc only runs Binaryen at link -O2+ (link.py: should_run_binaryen_optimizer
returns OPT_LEVEL >= 2) and we link at -O1, so the shipped module had never seen
wasm-opt at all — it kept its entire 19.56 MB name section, ~20% of the editor
(-sJSPI sets ASYNCIFY=2, which suppresses wasm-ld's --strip-debug, leaving
wasm-opt as the only thing that would drop it). Step 8.2 runs it post-link and
in-container, so CI's cached compile phase covers it and the host post-process
stays pure-host.

Default -O2, picked by measuring every level on the same module: -O0 already
captures 27% of the raw win (it is mostly the name section), -O2 costs 23 s and
gives the best frame rate, and -O3/-O4/-Os/-Oz cost 48-132 s for at most 1.5%
more brotli — -O4 is not even smaller than -O3. Targets that already link -O2/-Oz
(occ_service, kicad_tools) are skipped by testing for the target_features
section, which emcc strips whenever it ran the optimizer itself, so there is no
hard-coded target list to drift. Feature flags come from the module's own
target_features section and so cannot diverge from the link.

The perf specs reported requestAnimationFrame ticks as "FPS". That is not a frame
rate: rAF fires on the compositor's schedule whether or not the GAL redrew, and
it read 120/s on a board where the renderer completed zero frames in six seconds.
measureInteractionFps now counts completed GAL frames — runs of draws to the
default framebuffer, exactly one per frame in every AA mode — and drives a pure
middle-drag pan after a zoom-to-fit. Mixing wheel zoom into the drive made the
result depend on where the wheel left the view: +-20% across identical repeats,
against +-2% for pan alone. The report gains a GAL fps column with a regression
flag on the 1x number; rAF is kept so historical runs stay comparable.

CI has no GPU, so its number is a software-rasteriser redraw rate — a regression
signal, not a user-facing frame rate. Method and measurements in the bench report.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016X9eh1s5sTx1o9Em9KBuwR
This commit is contained in:
Viktor Vaczi 2026-08-22 12:53:00 +02:00
commit f419a1fedd
7 changed files with 536 additions and 56 deletions
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1
scripts/build-monitor.sh
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@ -98,6 +98,7 @@ BEGIN {
ord[++ROWN] = "kicad-configure"; lab["kicad-configure"] = "KiCad configure (CMake)"
ord[++ROWN] = "kicad-compile"; lab["kicad-compile"] = "KiCad compile"
ord[++ROWN] = "kicad-bitmaps"; lab["kicad-bitmaps"] = "Bitmap resources"
ord[++ROWN] = "wasm-opt"; lab["wasm-opt"] = "wasm-opt (Binaryen)"
ord[++ROWN] = "copy-output"; lab["copy-output"] = "Copy output"
ord[++ROWN] = "env-shim"; lab["env-shim"] = "ENV merge shim"
for (i = 1; i <= ROWN; i++) ridx[ord[i]] = i

27
scripts/kicad/build-kicad-target.sh
View file

@ -290,10 +290,12 @@ else
BUILD_TYPE="Release"
EXTRA_FLAGS="-O2 ${KICAD_EH_FLAGS} -matomics -mbulk-memory"
EMBIND_CONFIG_DEFINES="" # Release defines no DEBUG in either TU → vtable layouts already match
# -O0 at link time skips wasm-opt (which can OOM on large WASM files)
# Compilation is still -O2 for optimized code, but we skip post-link wasm-opt
# -O0 at link time means emcc does not run wasm-opt itself (it only does at
# -O2+). That is fine: step 8.2 below runs wasm-opt explicitly, so the module
# is optimized either way. The old "wasm-opt OOMs on large modules" reason for
# -O0 was Asyncify-era and no longer applies.
LINKER_DEBUG_FLAGS="-O0 ${KICAD_EH_FLAGS}"
log_info "Building KiCad in RELEASE mode (skipping wasm-opt due to memory limits)"
log_info "Building KiCad in RELEASE mode (post-link wasm-opt runs in step 8.2)"
fi
# Suspension backend: JSPI (native stack switching). The headless CLIs
@ -696,6 +698,25 @@ if [ "${APP_NAME}" != "kicad_tools" ] && [ "${APP_NAME}" != "occ_service" ]; the
emmake make bitmap_archive_build
fi
# Step 8.2: post-link Binaryen pass. emcc only runs wasm-opt at link -O2+
# (link.py: should_run_binaryen_optimizer -> OPT_LEVEL >= 2) and we link at -O1,
# so without this the module gets no Binaryen pass at all and keeps its whole
# name section (measured 19.56 MB, ~20% of the editor wasm — -sJSPI sets
# ASYNCIFY=2, which suppresses wasm-ld's --strip-debug, leaving wasm-opt as the
# only thing that would drop it). Skipped for targets that already link -O2/-Oz
# (occ_service, kicad_tools, ngspice_service): emcc strips target_features when
# it ran the optimizer itself, so there is no hard-coded target list to
# maintain. Feature flags come from the module's own target_features section and
# so cannot drift from the link. Override with KICAD_WASM_OPT ("-Oz" for the
# smallest raw module, "-O2 -g" to keep the name section, "off" to skip).
KICAD_WASM_OPT="${KICAD_WASM_OPT:--O2}"
if [ "${KICAD_WASM_OPT}" != "off" ] && grep -aq "target_features" "${LINK_OUT_WASM}"; then
kw_stage wasm-opt
log_info "wasm-opt ${KICAD_WASM_OPT} on ${APP_NAME}.wasm..."
"${EMSDK:-/emsdk}/upstream/bin/wasm-opt" ${KICAD_WASM_OPT} "${LINK_OUT_WASM}" -o "${LINK_OUT_WASM}.tmp"
mv -f "${LINK_OUT_WASM}.tmp" "${LINK_OUT_WASM}"
fi
# Step 9: Create stamp file
create_stamp "${KICAD_STAMP}"
log_info "KiCad ${APP_NAME} build complete!"