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| author | Rodrigo Arias Mallo <rodarima@gmail.com> | 2025-09-28 20:26:15 +0200 |
|---|---|---|
| committer | Rodrigo <rodarima@gmail.com> | 2025-09-28 23:10:55 +0200 |
| commit | fb510ea86be5ceb9e91573890242581fdbd77ad8 (patch) | |
| tree | d819fe40683592008d136727f5a0b03e48dc1164 /380 | |
Diffstat (limited to '380')
| -rw-r--r-- | 380/index.md | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/380/index.md b/380/index.md new file mode 100644 index 0000000..7966cea --- /dev/null +++ b/380/index.md @@ -0,0 +1,130 @@ +Title: Performance improvements +Author: rodarima +Created: Sun, 13 Apr 2025 16:52:07 +0000 +State: open + +Rendering https://html.spec.whatwg.org/ several times (via refresh) leads to the following perf trace on armv7: + +``` +# To display the perf.data header info, please use --header/--header-only options. +# +# +# Total Lost Samples: 0 +# +# Samples: 169K of event 'cycles:Pu' +# Event count (approx.): 33718562150 +# +# Overhead Command Shared Object Symbol +# ........ ....... ....................... ................................................................................................................................................ +# + 7.03% dillo dillo [.] lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const + 6.34% dillo ld-musl-armhf.so.1 [.] __strchrnul + 2.69% dillo dillo [.] Html_write_raw(DilloHtml*, char*, int, int) + 2.22% dillo ld-musl-armhf.so.1 [.] __libc_malloc_impl + 1.91% dillo ld-musl-armhf.so.1 [.] strncmp + 1.86% dillo dillo [.] lout::misc::NotSoSimpleVector<dw::Textblock::Word>::size() const + 1.78% dillo dillo [.] dw::Textblock::accumulateWordData(int) + 1.64% dillo libz.so.1.3.1 [.] crc32_z + 1.51% dillo ld-musl-armhf.so.1 [.] get_meta + 1.45% dillo dillo [.] CssStyleSheet::apply(CssPropertyList*, Doctree*, DoctreeNode const*, MatchCache*) const + 1.37% dillo dillo [.] int lout::misc::max<int>(int, int) + 1.29% dillo dillo [.] dw::Textblock::BadnessAndPenalty::penaltyValue(int, int) + 1.29% dillo ld-musl-armhf.so.1 [.] strcspn + 1.22% dillo ld-musl-armhf.so.1 [.] __libc_free + 1.20% dillo dillo [.] dw::Textblock::BadnessAndPenalty::badnessValue(int) + 1.17% dillo dillo [.] lout::identity::IdentifiableObject::instanceOf(int) + 1.16% dillo dillo [.] dw::Textblock::addText(char const*, unsigned int, dw::core::style::Style*) + 1.16% dillo dillo [.] dw::Textblock::wrapWordInFlow(int, bool) + 1.09% dillo dillo [.] a_Html_get_attr(DilloHtml*, char const*, int, char const*) + 1.03% dillo dillo [.] dw::Textblock::getWidgetRegardingBorderForLine(int, int) + 1.00% dillo dillo [.] CssSelector::match(Doctree*, DoctreeNode const*, int, CssSelector::Combinator, MatchCache*) + 0.92% dillo ld-musl-armhf.so.1 [.] cached_aligned32 + 0.89% dillo dillo [.] dw::Textblock::getLineStretchability(int) + 0.86% dillo ld-musl-armhf.so.1 [.] strlen + 0.85% dillo dillo [.] dw::core::Widget::getStyle() + 0.85% dillo dillo [.] dw::Textblock::calcBorders(int, int) + 0.83% dillo dillo [.] dw::Textblock::handleWordExtremes(int) + 0.80% dillo ld-musl-armhf.so.1 [.] alloc_slot + 0.79% dillo dillo [.] dw::Textblock::BadnessAndPenalty::compareTo(int, dw::Textblock::BadnessAndPenalty*) + 0.78% dillo dillo [.] lout::misc::SimpleVector<dw::Textblock::Line>::size() const + 0.77% dillo dillo [.] lout::container::untyped::Vector::get(int) const + 0.77% dillo dillo [.] lout::object::ConstString::hashValue(char const*) + 0.66% dillo libgcc_s.so.1 [.] __aeabi_idiv + 0.66% dillo dillo [.] CssSimpleSelector::match(DoctreeNode const*) + 0.64% dillo dillo [.] lout::container::untyped::HashSet::findNode(lout::object::Object*) const + 0.63% dillo dillo [.] lout::misc::SimpleVector<dw::Textblock::Line>::getRef(int) const +``` + +There is a bottleneck in getRef of the NotSoSimpleVector. We could probably optimize the hot path as it is doing several checks that are not really needed. Including two asserts. + +``` + │ 0005f7fc <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const>: ▒ + │ /** ▒ + │ * \brief Return the reference of one element. ▒ + │ * ▒ + │ * \sa misc::SimpleVector::get ▒ + │ */ ▒ + │ inline T* getRef (int i) const ▒ + 2.72 │ push {r7, lr} ▒ + 1.83 │ sub sp, #8 ▒ + 2.42 │ add r7, sp, #0 ▒ + 5.87 │ str r0, [r7, #4] ▒ + 1.99 │ str r1, [r7, #0] ▒ + │ { ▒ + │ if (this->startExtra == -1) { ▒ + 2.01 │ ldr r3, [r7, #4] ▒ + 5.73 │ ldr r3, [r3, #28] ▒ + 3.61 │ cmp.w r3, #4294967295 ▒ + │ bne.n 5f84e <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x52> ▒ + │ assert (i >= 0 && i < this->numMain); ▒ + 5.79 │ ldr r3, [r7, #0] ▒ + 3.48 │ cmp r3, #0 ▒ + 0.34 │ blt.n 5f820 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x24> ▒ + 5.49 │ ldr r3, [r7, #4] ▒ + 5.47 │ ldr r3, [r3, #12] ▒ + 1.67 │ ldr r2, [r7, #0] ▒ + 3.40 │ cmp r2, r3 ▒ + │ blt.n 5f834 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x38> ▒ + │ ldr r3, [pc, #228] @ (5f908 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x10c>) ▒ + │ add r3, pc ▒ + │ movw r2, #479 @ 0x1df ▒ + │ ldr r1, [pc, #224] @ (5f90c <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x110>) ▒ + │ add r1, pc ▒ + │ ldr r0, [pc, #224] @ (5f910 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x114>) ▒ + │ add r0, pc ▒ + │ → blx strrchr@plt ▒ + │ return this->arrayMain + i; ▒ + 5.98 │ ldr r3, [r7, #4] ▒ + 5.65 │ ldr r1, [r3, #0] ▒ + 1.80 │ ldr r2, [r7, #0] ▒ + 3.96 │ mov r3, r2 ▒ + 4.10 │ lsls r3, r3, #1 ▒ + 1.86 │ add r3, r2 ▒ + 3.54 │ lsls r2, r3, #3 ▒ + 1.68 │ subs r2, r2, r3 ▒ + 3.85 │ lsls r3, r2, #2 ▒ + 2.06 │ mov r2, r3 ▒ + 1.84 │ mov r3, r2 ▒ + 2.02 │ add r3, r1 ▒ + │ b.n 5f8fe <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x102> ▒ + │ } else { ▒ + │ if (i < this->startExtra) { ▒ + │ ldr r3, [r7, #4] ▒ + │ ldr r3, [r3, #28] ▒ + │ ldr r2, [r7, #0] ▒ + │ cmp r2, r3 ▒ + │ bge.n 5f88c <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x90> ▒ + │ assert (i >= 0); ▒ + │ ldr r3, [r7, #0] ▒ + │ cmp r3, #0 ▒ + │ bge.n 5f872 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x76> ▒ + │ ldr r3, [pc, #180] @ (5f914 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x118>) ▒ + │ add r3, pc ▒ + │ movw r2, #483 @ 0x1e3 ▒ + │ ldr r1, [pc, #176] @ (5f918 <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x11c>) ▒ + │ add r1, pc ▒ + │ ldr r0, [pc, #176] @ (5f91c <lout::misc::NotSoSimpleVector<dw::Textblock::Word>::getRef(int) const+0x120>) ▒ + │ add r0, pc ▒ + │ → blx strrchr@plt +... +```
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