Less optimistic checking for const vector to pattern checks - #124599

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Less optimistic checking for const vector to pattern checks#124599
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Fixes#124511

When checking a element of TBase size, ensure that no other bits other than the first bit are set

@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI review requested due to automatic review settings February 19, 2026 14:42
@github-actionsgithub-actionsBot added the area-CodeGen-coreclr CLR JIT compiler in src/coreclr/src/jit and related components such as SuperPMI label Feb 19, 2026
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Pull request overview

This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.

Changes:

  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic

Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
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Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

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@a74nha74nh changed the title Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Seems like one of the existing SVE regression tests is failing with this change.

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a74nh commented Feb 23, 2026

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Seems like one of the existing SVE regression tests is failing with this change.

That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026
Open
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jakobbotsch merged commit 3b61bfa into dotnet:mainFeb 24, 2026
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JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics

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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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Less optimistic checking for const vector to pattern checks - #124599
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jakobbotsch merged 9 commits into
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a74nh:minus3_github
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Merged
Less optimistic checking for const vector to pattern checks#124599
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
jakobbotsch
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Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.cs
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

Open


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@jakobbotsch
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merged commit 3b61bfa
into
dotnet:mainFeb 24, 2026

130 of 134 checks passed

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@a74nh@iremyux
JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Less optimistic checking for const vector to pattern checks - #124599
Merged
jakobbotsch merged 9 commits into
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a74nh:minus3_github
Feb 24, 2026
Merged
Less optimistic checking for const vector to pattern checks#124599
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
February 19, 2026 14:42
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
jakobbotsch
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reviewed
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Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.cs
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

Open


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@jakobbotsch
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merged commit 3b61bfa
into
dotnet:mainFeb 24, 2026

130 of 134 checks passed

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minus3_github

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@a74nh@iremyux
JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Less optimistic checking for const vector to pattern checks - #124599
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Less optimistic checking for const vector to pattern checks#124599
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
jakobbotsch
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Feb 19, 2026
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Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

Open


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@jakobbotsch
jakobbotsch
merged commit 3b61bfa
into
dotnet:mainFeb 24, 2026

130 of 134 checks passed

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JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

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Less optimistic checking for const vector to pattern checks - #124599
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Less optimistic checking for const vector to pattern checks#124599
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
jakobbotsch
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Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.cs
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

Open


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@jakobbotsch
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merged commit 3b61bfa
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dotnet:mainFeb 24, 2026

130 of 134 checks passed

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@a74nh@iremyux
JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Less optimistic checking for const vector to pattern checks - #124599
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jakobbotsch merged 9 commits into
dotnet:mainfrom 
a74nh:minus3_github
Feb 24, 2026
Merged
Less optimistic checking for const vector to pattern checks#124599
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
February 19, 2026 14:42
@github-actionsgithub-actionsBot
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
jakobbotsch
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reviewed
Feb 19, 2026
View reviewed changes
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.cs
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

Open


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@jakobbotsch
jakobbotsch
merged commit 3b61bfa
into
dotnet:mainFeb 24, 2026

130 of 134 checks passed

@a74nh
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minus3_github

branch
February 24, 2026 13:03
@dotnet-maestrodotnet-maestroBot
mentioned this pull request
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iremyux pushed a commit
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Mar 2, 2026
@a74nh@iremyux
JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics


3 participants

@a74nh@jakobbotsch

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Less optimistic checking for const vector to pattern checks - #124599
Merged
jakobbotsch merged 9 commits into
dotnet:mainfrom 
a74nh:minus3_github
Feb 24, 2026
Merged
Less optimistic checking for const vector to pattern checks#124599
jakobbotsch merged 9 commits into
dotnet:mainfrom 
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
February 19, 2026 14:42
@github-actionsgithub-actionsBot
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
jakobbotsch
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reviewed
Feb 19, 2026
View reviewed changes
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

Open


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@jakobbotsch
jakobbotsch
merged commit 3b61bfa
into
dotnet:mainFeb 24, 2026

130 of 134 checks passed

@a74nh
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deleted the

minus3_github

branch
February 24, 2026 13:03
@dotnet-maestrodotnet-maestroBot
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iremyux pushed a commit
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Mar 2, 2026
@a74nh@iremyux
JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics


3 participants

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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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Less optimistic checking for const vector to pattern checks - #124599
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jakobbotsch merged 9 commits into
dotnet:mainfrom 
a74nh:minus3_github
Feb 24, 2026
Merged
Less optimistic checking for const vector to pattern checks#124599
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dotnet:mainfrom 
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Fixes#124511
When checking a element of TBase size, ensure that no other bits other than the first bit are set
@a74nh
Less optimistic checks for const vector to pattern checks
99cf54d
Fixesdotnet#124511
When checking a element of TBase size, ensure that no other bits
other than the first bit are set
CopilotAI
review requested due to automatic review settings
February 19, 2026 14:42
@github-actionsgithub-actionsBot
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Pull request overview
This PR fixes a JIT bug in ARM64 SVE intrinsics where constant vector patterns were incorrectly validated, leading to wrong results. The issue was that EvaluateSimdMaskToPattern only checked the lowest bit of each mask element, allowing invalid masks with extra bits set to pass validation.
Changes:
  • Enhanced mask validation to check all bits in each TBase-sized element, not just the lowest bit
  • Renamed finalOne to firstZero for clarity
  • Updated comments to better explain the mask format and validation logic
Comment threadsrc/coreclr/jit/simd.h
Comment threadsrc/coreclr/jit/simd.h
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Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.csproj
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
Comment threadsrc/tests/JIT/Regression/JitBlue/Runtime_124511/Runtime_124511.cs
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@a74nha74nh
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Less optimistic checks for const vector to pattern checksLess optimistic checking for const vector to pattern checksFeb 20, 2026
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Pull request overview
Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.
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Seems like one of the existing SVE regression tests is failing with this change.
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Seems like one of the existing SVE regression tests is failing with this change.
That's fixed now - just an issue with creating the mask for longs.

This was referenced Feb 23, 2026

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JIT: Less optimistic checking for const vector to pattern checks (dot…
e45a28b
…net#124599)
When checking a element of TBase size, ensure that no other bits other
than the first bit are set
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JIT: Invalid result with SVE intrinsics


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