From 5e389d8c9b3f0fa45059274c1ff02be13ff1bc06 Mon Sep 17 00:00:00 2001 From: Ruslan Shestopalyuk Date: Sat, 28 Dec 2024 01:42:44 -0800 Subject: [PATCH] Avoid calling fmod twice in roundLayoutResultsToPixelGrid Summary: X-link: https://github.com/facebook/react-native/pull/48404 ## Changelog: [Internal] - This popped up when profiling some heavy UI performance, calling `fmod` operation in Yoga's `roundLayoutResultsToPixelGrid` in `PixelGrid.cpp` can be expensive, furthermore it turns that some of the calls were redundant. This replaces the duplicate calls to fmod with an equivalent single round operation, which for clang compiler on Windows bring the code in question from ~50 instructions (including 4 call instructions to the fmod function) down to ~30 instructions (without any external calls), and the layout operation being **~1% more efficient** for the particular benchmark I was looking into. Differential Revision: D67689065 --- yoga/algorithm/PixelGrid.cpp | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/yoga/algorithm/PixelGrid.cpp b/yoga/algorithm/PixelGrid.cpp index 7a694565e9..01fdeb4639 100644 --- a/yoga/algorithm/PixelGrid.cpp +++ b/yoga/algorithm/PixelGrid.cpp @@ -66,7 +66,8 @@ void roundLayoutResultsToPixelGrid( yoga::Node* const node, const double absoluteLeft, const double absoluteTop) { - const auto pointScaleFactor = node->getConfig()->getPointScaleFactor(); + const double pointScaleFactor = + static_cast(node->getConfig()->getPointScaleFactor()); const double nodeLeft = node->getLayout().position(PhysicalEdge::Left); const double nodeTop = node->getLayout().position(PhysicalEdge::Top); @@ -80,7 +81,7 @@ void roundLayoutResultsToPixelGrid( const double absoluteNodeRight = absoluteNodeLeft + nodeWidth; const double absoluteNodeBottom = absoluteNodeTop + nodeHeight; - if (pointScaleFactor != 0.0f) { + if (pointScaleFactor != 0.0) { // If a node has a custom measure function we never want to round down its // size as this could lead to unwanted text truncation. const bool textRounding = node->getNodeType() == NodeType::Text; @@ -96,12 +97,14 @@ void roundLayoutResultsToPixelGrid( // We multiply dimension by scale factor and if the result is close to the // whole number, we don't have any fraction To verify if the result is close // to whole number we want to check both floor and ceil numbers + + const double scaledNodeWith = nodeWidth * pointScaleFactor; const bool hasFractionalWidth = - !yoga::inexactEquals(fmod(nodeWidth * pointScaleFactor, 1.0), 0) && - !yoga::inexactEquals(fmod(nodeWidth * pointScaleFactor, 1.0), 1.0); + !yoga::inexactEquals(round(scaledNodeWith), scaledNodeWith); + + const double scaledNodeHeight = nodeHeight * pointScaleFactor; const bool hasFractionalHeight = - !yoga::inexactEquals(fmod(nodeHeight * pointScaleFactor, 1.0), 0) && - !yoga::inexactEquals(fmod(nodeHeight * pointScaleFactor, 1.0), 1.0); + !yoga::inexactEquals(round(scaledNodeHeight), scaledNodeHeight); node->setLayoutDimension( roundValueToPixelGrid(