Fix assert in x86 when using custom align

[acoates-ms]

Port #16145 to main

Microsoft Reviewers: Open in CodeFlow

[github-actions]

Performance Test Results

Branch: spookyx86
Commit: 97598c94
Time: 2026-05-18T21:35:13.994Z
Tests: 161/161 passed

✅ Passed

161 scenario(s) across 28 suite(s) — no regressions

SectionList

Scenario	Mean	Median	StdDev	Renders	vs Baseline
SectionList mount	4.60ms	5.00ms	±0.52ms	1	+0.0%
SectionList unmount	0.30ms	0.00ms	±0.48ms	0	+0.0%
SectionList rerender	11.50ms	10.50ms	±2.80ms	2	+0.0%
SectionList with-3-sections-15-items	6.40ms	6.50ms	±0.97ms	1	+18.2%
SectionList with-5-sections-50-items	6.20ms	6.50ms	±1.23ms	1	+8.3%
SectionList with-10-sections-200-items	5.00ms	5.00ms	±0.47ms	1	-9.1%
SectionList with-20-sections-200-items	5.00ms	5.00ms	±2.49ms	1	+0.0%
SectionList with-section-separator	1.90ms	2.00ms	±0.32ms	1	+0.0%
SectionList with-item-separator	2.40ms	2.00ms	±0.84ms	1	+0.0%
SectionList with-header-footer	2.20ms	2.00ms	±0.63ms	1	+0.0%
SectionList with-section-footer	1.70ms	2.00ms	±0.67ms	1	+0.0%
SectionList with-sticky-section-headers	2.10ms	1.50ms	±2.13ms	1	-25.0%
SectionList with-empty-list	0.30ms	0.00ms	±0.48ms	1	-100.0%
SectionList with-50-sections-1000-items	1.30ms	1.00ms	±0.48ms	1	-50.0%

FlatList

Scenario	Mean	Median	StdDev	Renders	vs Baseline
FlatList mount	4.20ms	4.00ms	±0.92ms	1	+0.0%
FlatList unmount	0.20ms	0.00ms	±0.42ms	0	+0.0%
FlatList rerender	11.30ms	11.50ms	±1.64ms	2	+27.8%
FlatList with-10-items	4.90ms	5.00ms	±1.10ms	1	+25.0%
FlatList with-100-items	5.90ms	5.00ms	±2.42ms	1	+0.0%
FlatList with-500-items	4.70ms	4.00ms	±1.57ms	1	+0.0%
FlatList with-1000-items	5.20ms	4.50ms	±1.87ms	1	+12.5%
FlatList horizontal	4.00ms	4.00ms	±1.15ms	1	-20.0%
FlatList with-separator	1.70ms	2.00ms	±0.48ms	1	+0.0%
FlatList with-header-footer	1.50ms	1.50ms	±0.53ms	1	-25.0%
FlatList with-empty-list	0.50ms	0.50ms	±0.53ms	1	+0.0%
FlatList with-get-item-layout	1.50ms	1.00ms	±0.97ms	1	+0.0%
FlatList inverted	2.40ms	2.00ms	±2.72ms	1	+33.3%
FlatList with-num-columns	2.20ms	2.00ms	±0.63ms	1	-33.3%

TouchableOpacity

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableOpacity mount	1.00ms	1.00ms	±0.00ms	1	+0.0%
TouchableOpacity unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
TouchableOpacity rerender	1.00ms	1.00ms	±0.47ms	2	+0.0%
TouchableOpacity custom-active-opacity	0.80ms	1.00ms	±0.42ms	1	+0.0%
TouchableOpacity disabled	0.60ms	1.00ms	±0.52ms	1	+0.0%
TouchableOpacity with-all-handlers	0.40ms	0.00ms	±0.52ms	1	-100.0%
TouchableOpacity with-hit-slop	1.00ms	1.00ms	±0.00ms	1	+0.0%
TouchableOpacity with-delay	0.80ms	1.00ms	±0.42ms	1	+0.0%
TouchableOpacity nested	1.30ms	1.00ms	±0.48ms	1	+0.0%
TouchableOpacity multiple-10	6.27ms	6.00ms	±2.19ms	1	+0.0%
TouchableOpacity multiple-50	29.93ms	25.00ms	±16.30ms	1	-13.8%
TouchableOpacity multiple-100	42.00ms	47.00ms	±12.82ms	1	-6.0%

ScrollView

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ScrollView mount	0.80ms	0.00ms	±1.55ms	1	+0.0%
ScrollView unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
ScrollView rerender	0.70ms	1.00ms	±0.48ms	2	+0.0%
ScrollView children-20	3.27ms	3.00ms	±0.59ms	1	-25.0%
ScrollView children-100	16.60ms	16.00ms	±3.44ms	1	+0.0%
ScrollView horizontal	3.10ms	3.00ms	±0.32ms	1	-25.0%
ScrollView sticky-headers	3.00ms	3.00ms	±1.63ms	1	+0.0%
ScrollView scroll-indicators	0.80ms	1.00ms	±0.42ms	1	+0.0%
ScrollView nested	2.30ms	2.00ms	±1.16ms	1	+100.0%
ScrollView content-container-style	0.80ms	1.00ms	±0.42ms	1	+0.0%
ScrollView children-500	20.07ms	21.00ms	±3.63ms	1	+10.5%

TouchableHighlight

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableHighlight mount	0.30ms	0.00ms	±0.48ms	1	-100.0%
TouchableHighlight unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
TouchableHighlight rerender	0.60ms	1.00ms	±0.52ms	2	+0.0%
TouchableHighlight custom-underlay-color	0.50ms	0.50ms	±0.53ms	1	+Infinity%
TouchableHighlight custom-active-opacity	0.90ms	0.00ms	±1.85ms	1	+0.0%
TouchableHighlight disabled	0.40ms	0.00ms	±0.52ms	1	+0.0%
TouchableHighlight with-all-handlers	0.40ms	0.00ms	±0.52ms	1	+0.0%
TouchableHighlight with-hit-slop	0.40ms	0.00ms	±0.52ms	1	+0.0%
TouchableHighlight nested-touchables	0.80ms	1.00ms	±0.42ms	1	+0.0%
TouchableHighlight multiple-touchables-10	2.20ms	2.00ms	±0.63ms	1	-33.3%
TouchableHighlight multiple-touchables-50	12.70ms	11.50ms	±2.31ms	1	-8.0%
TouchableHighlight multiple-touchables-100	23.00ms	22.50ms	±3.94ms	1	+0.0%

Pressable

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Pressable mount	0.40ms	0.00ms	±0.52ms	1	+0.0%
Pressable unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
Pressable rerender	0.30ms	0.00ms	±0.48ms	2	-100.0%
Pressable with-all-handlers	0.40ms	0.00ms	±0.52ms	1	+0.0%
Pressable with-style-function	0.30ms	0.00ms	±0.48ms	1	+0.0%
Pressable disabled	0.20ms	0.00ms	±0.42ms	1	+0.0%
Pressable with-hit-slop	0.30ms	0.00ms	±0.48ms	1	+0.0%
Pressable nested	0.70ms	1.00ms	±0.48ms	1	+0.0%
Pressable multiple-10	2.93ms	3.00ms	±1.28ms	1	+0.0%
Pressable multiple-50	13.60ms	14.00ms	±1.68ms	1	+0.0%
Pressable multiple-100	14.60ms	11.00ms	±8.74ms	1	-8.3%

Modal

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Modal mount	0.30ms	0.00ms	±0.48ms	1	+0.0%
Modal unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Modal rerender	0.60ms	0.50ms	±0.70ms	2	+Infinity%
Modal slide-animation	0.30ms	0.00ms	±0.48ms	1	+0.0%
Modal fade-animation	0.20ms	0.00ms	±0.42ms	1	+0.0%
Modal transparent	0.10ms	0.00ms	±0.32ms	1	+0.0%
Modal with-callbacks	0.30ms	0.00ms	±0.48ms	1	+0.0%
Modal rich-content	1.40ms	1.00ms	±0.52ms	1	-50.0%
Modal with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%

Image

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Image mount	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
Image rerender	0.30ms	0.00ms	±0.48ms	2	+0.0%
Image with-resize-mode	0.20ms	0.00ms	±0.42ms	1	+0.0%
Image with-border-radius	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image with-tint-color	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image with-blur-radius	0.10ms	0.00ms	±0.32ms	1	+0.0%
Image with-accessibility	0.00ms	0.00ms	±0.00ms	1	+0.0%
Image multiple-10	1.20ms	1.00ms	±1.08ms	1	+0.0%
Image multiple-50	3.27ms	3.00ms	±0.59ms	1	+0.0%
Image multiple-100	7.87ms	7.00ms	±2.70ms	1	-12.5%

ActivityIndicator

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ActivityIndicator mount	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator unmount	0.10ms	0.00ms	±0.32ms	0	+0.0%
ActivityIndicator rerender	0.00ms	0.00ms	±0.00ms	2	+0.0%
ActivityIndicator size-large	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator size-small	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator with-color	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator not-animating	0.10ms	0.00ms	±0.32ms	1	+0.0%
ActivityIndicator with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%
ActivityIndicator multiple-10	1.00ms	1.00ms	±0.93ms	1	+0.0%
ActivityIndicator multiple-50	3.60ms	3.00ms	±0.74ms	1	-25.0%
ActivityIndicator multiple-100	7.33ms	7.00ms	±1.18ms	1	+0.0%

Switch

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Switch mount	0.60ms	0.00ms	±1.26ms	1	+0.0%
Switch unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Switch rerender	0.40ms	0.00ms	±0.52ms	2	-100.0%
Switch value-true	0.30ms	0.00ms	±0.48ms	1	+0.0%
Switch disabled	0.30ms	0.00ms	±0.48ms	1	+0.0%
Switch custom-colors	0.20ms	0.00ms	±0.42ms	1	+0.0%
Switch on-value-change	0.20ms	0.00ms	±0.42ms	1	+0.0%
Switch with-accessibility	0.20ms	0.00ms	±0.42ms	1	+0.0%
Switch multiple-10	1.67ms	1.00ms	±1.54ms	1	-50.0%
Switch multiple-50	9.13ms	8.00ms	±2.61ms	1	-11.1%
Switch multiple-100	18.87ms	18.00ms	±4.37ms	1	+12.5%

Button

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Button mount	0.60ms	1.00ms	±0.52ms	1	+0.0%
Button unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Button rerender	0.90ms	1.00ms	±0.32ms	2	+0.0%
Button disabled	0.50ms	0.50ms	±0.53ms	1	-50.0%
Button with-color	0.50ms	0.50ms	±0.53ms	1	+0.0%
Button with-accessibility	0.50ms	0.50ms	±0.53ms	1	-50.0%
Button multiple-10	5.00ms	5.00ms	±1.81ms	1	-16.7%
Button multiple-50	19.47ms	23.00ms	±7.35ms	1	-14.8%
Button multiple-100	14.87ms	14.00ms	±2.75ms	1	-26.3%

TextInput

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TextInput mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
TextInput unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
TextInput rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
TextInput multiline	0.20ms	0.00ms	±0.42ms	1	+0.0%
TextInput with-value	0.10ms	0.00ms	±0.32ms	1	+0.0%
TextInput styled	0.00ms	0.00ms	±0.00ms	1	+0.0%
TextInput multiple-100	6.60ms	6.00ms	±1.50ms	1	-14.3%

View

Scenario	Mean	Median	StdDev	Renders	vs Baseline
View mount	0.10ms	0.00ms	±0.32ms	1	+0.0%
View unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
View rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
View nested-50	3.53ms	3.00ms	±1.30ms	1	+0.0%
View nested-100	7.53ms	7.00ms	±1.30ms	1	+0.0%
View shadow	0.20ms	0.00ms	±0.42ms	1	+0.0%
View border-radius	0.10ms	0.00ms	±0.32ms	1	+0.0%
View nested-500	20.20ms	19.00ms	±11.31ms	1	+90.0%

Text

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Text mount	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text unmount	0.00ms	0.00ms	±0.00ms	0	+0.0%
Text rerender	0.20ms	0.00ms	±0.42ms	2	+0.0%
Text long-1000	0.60ms	0.00ms	±1.58ms	1	+0.0%
Text nested	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text styled	0.20ms	0.00ms	±0.42ms	1	+0.0%
Text multiple-100	8.00ms	8.00ms	±1.36ms	1	+14.3%

SectionList.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
SectionList native mount	4.67ms	4.37ms	±0.53ms	1	-32.8%

FlatList.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
FlatList native mount	5.03ms	4.66ms	±1.21ms	1	-49.6%

TouchableHighlight.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableHighlight native mount	1.33ms	1.28ms	±0.13ms	1	-38.5%

TouchableOpacity.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TouchableOpacity native mount	1.71ms	1.48ms	±0.73ms	1	-52.7%

Pressable.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Pressable native mount	1.58ms	1.54ms	±0.23ms	1	-38.8%

ScrollView.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ScrollView native mount	3.30ms	3.10ms	±0.47ms	1	-23.3%

ActivityIndicator.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
ActivityIndicator native mount	1.38ms	1.32ms	±0.18ms	1	-46.9%

TextInput.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
TextInput native mount	2.05ms	2.04ms	±0.14ms	1	-50.1%

Switch.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Switch native mount	1.16ms	1.13ms	±0.13ms	1	-34.9%

Button.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Button native mount	1.86ms	1.80ms	±0.22ms	1	-30.7%

Modal.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Modal native mount	1.00ms	0.92ms	±0.22ms	1	-24.2%

Image.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Image native mount	1.98ms	1.63ms	±0.87ms	1	-28.1%

View.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
View native mount	1.11ms	1.08ms	±0.19ms	1	-24.5%

Text.native-perf-test.ts

Scenario	Mean	Median	StdDev	Renders	vs Baseline
Text native mount	1.26ms	1.20ms	±0.18ms	1	-31.3%