Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980

Open
Open
Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
Labels
P2Priority of the issue for triage purpose: Needs to be fixed at some point.

Description

@briancylui
briancylui
opened on Sep 21, 2018

#821 references and aims to solve this issue.

Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).

Perf tests results before and after the change are shown below:

Before the change:

BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
TypeMethodMeanErrorStdDev
AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
NativePerformanceTestsAddU330.1 us3.585 us3.178 us
SsePerformanceTestsAddU325.6 us6.883 us7.926 us

After the change:

BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
TypeMethodMeanErrorStdDev
AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
NativePerformanceTestsSumU281.6 us5.261 us4.921 us
SsePerformanceTestsSumU294.1 us2.080 us1.946 us
AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
NativePerformanceTestsAddU335.1 us3.053 us2.707 us
SsePerformanceTestsAddU345.0 us2.155 us1.800 us

Both SSE and AVX implementations are slower by 10-20% after this change.

In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):

var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.

cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer

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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" + '

      Skip to content
      Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
      Open
      Open
      Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
      Labels
      P2Priority of the issue for triage purpose: Needs to be fixed at some point.
      Description
      @briancylui
      briancylui
      opened on Sep 21, 2018
      #821 references and aims to solve this issue.
      Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
      Perf tests results before and after the change are shown below:
      Before the change:
      BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
      TypeMethodMeanErrorStdDev
      AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
      NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
      SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
      AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
      NativePerformanceTestsAddU330.1 us3.585 us3.178 us
      SsePerformanceTestsAddU325.6 us6.883 us7.926 us
      After the change:
      BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
      TypeMethodMeanErrorStdDev
      AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
      NativePerformanceTestsSumU281.6 us5.261 us4.921 us
      SsePerformanceTestsSumU294.1 us2.080 us1.946 us
      AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
      NativePerformanceTestsAddU335.1 us3.053 us2.707 us
      SsePerformanceTestsAddU345.0 us2.155 us1.800 us
      Both SSE and AVX implementations are slower by 10-20% after this change.
      In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
      var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

      Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
      cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
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          No milestone
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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
          Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
          Open
          Open
          Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
          Labels
          P2Priority of the issue for triage purpose: Needs to be fixed at some point.
          Description
          @briancylui
          briancylui
          opened on Sep 21, 2018
          #821 references and aims to solve this issue.
          Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
          Perf tests results before and after the change are shown below:
          Before the change:
          BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
          TypeMethodMeanErrorStdDev
          AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
          NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
          SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
          AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
          NativePerformanceTestsAddU330.1 us3.585 us3.178 us
          SsePerformanceTestsAddU325.6 us6.883 us7.926 us
          After the change:
          BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
          TypeMethodMeanErrorStdDev
          AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
          NativePerformanceTestsSumU281.6 us5.261 us4.921 us
          SsePerformanceTestsSumU294.1 us2.080 us1.946 us
          AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
          NativePerformanceTestsAddU335.1 us3.053 us2.707 us
          SsePerformanceTestsAddU345.0 us2.155 us1.800 us
          Both SSE and AVX implementations are slower by 10-20% after this change.
          In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
          var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

          Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
          cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
          Metadata
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          No one assigned
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            P2Priority of the issue for triage purpose: Needs to be fixed at some point.
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            No type
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            No projects
              Milestone
              No milestone
              Relationships
              None yet
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              No branches or pull requests
              Issue actions
              
, '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('^' + ".*" + '

              Skip to content
              Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
              Open
              Open
              Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
              Labels
              P2Priority of the issue for triage purpose: Needs to be fixed at some point.
              Description
              @briancylui
              briancylui
              opened on Sep 21, 2018
              #821 references and aims to solve this issue.
              Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
              Perf tests results before and after the change are shown below:
              Before the change:
              BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
              TypeMethodMeanErrorStdDev
              AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
              NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
              SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
              AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
              NativePerformanceTestsAddU330.1 us3.585 us3.178 us
              SsePerformanceTestsAddU325.6 us6.883 us7.926 us
              After the change:
              BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
              TypeMethodMeanErrorStdDev
              AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
              NativePerformanceTestsSumU281.6 us5.261 us4.921 us
              SsePerformanceTestsSumU294.1 us2.080 us1.946 us
              AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
              NativePerformanceTestsAddU335.1 us3.053 us2.707 us
              SsePerformanceTestsAddU345.0 us2.155 us1.800 us
              Both SSE and AVX implementations are slower by 10-20% after this change.
              In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
              var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

              Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
              cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
              Metadata
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              Assignees
              No one assigned
                Labels
                P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                Type
                No type
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
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                  No branches or pull requests
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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" + '

                  Skip to content
                  Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
                  Open
                  Open
                  Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
                  Labels
                  P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                  Description
                  @briancylui
                  briancylui
                  opened on Sep 21, 2018
                  #821 references and aims to solve this issue.
                  Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
                  Perf tests results before and after the change are shown below:
                  Before the change:
                  BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                  TypeMethodMeanErrorStdDev
                  AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
                  NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
                  SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
                  AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
                  NativePerformanceTestsAddU330.1 us3.585 us3.178 us
                  SsePerformanceTestsAddU325.6 us6.883 us7.926 us
                  After the change:
                  BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                  TypeMethodMeanErrorStdDev
                  AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
                  NativePerformanceTestsSumU281.6 us5.261 us4.921 us
                  SsePerformanceTestsSumU294.1 us2.080 us1.946 us
                  AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
                  NativePerformanceTestsAddU335.1 us3.053 us2.707 us
                  SsePerformanceTestsAddU345.0 us2.155 us1.800 us
                  Both SSE and AVX implementations are slower by 10-20% after this change.
                  In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
                  var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

                  Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
                  cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                    Type
                    No type
                    Projects
                    No projects
                      Milestone
                      No milestone
                      Relationships
                      None yet
                      Development
                      No branches or pull requests
                      Issue actions
                      
, '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('^' + ".*" + '

                      Skip to content
                      Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
                      Open
                      Open
                      Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
                      Labels
                      P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                      Description
                      @briancylui
                      briancylui
                      opened on Sep 21, 2018
                      #821 references and aims to solve this issue.
                      Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
                      Perf tests results before and after the change are shown below:
                      Before the change:
                      BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                      TypeMethodMeanErrorStdDev
                      AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
                      NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
                      SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
                      AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
                      NativePerformanceTestsAddU330.1 us3.585 us3.178 us
                      SsePerformanceTestsAddU325.6 us6.883 us7.926 us
                      After the change:
                      BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                      TypeMethodMeanErrorStdDev
                      AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
                      NativePerformanceTestsSumU281.6 us5.261 us4.921 us
                      SsePerformanceTestsSumU294.1 us2.080 us1.946 us
                      AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
                      NativePerformanceTestsAddU335.1 us3.053 us2.707 us
                      SsePerformanceTestsAddU345.0 us2.155 us1.800 us
                      Both SSE and AVX implementations are slower by 10-20% after this change.
                      In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
                      var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

                      Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
                      cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
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, '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('^' + ".*" + '

                          Skip to content
                          Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
                          Open
                          Open
                          Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
                          Labels
                          P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                          Description
                          @briancylui
                          briancylui
                          opened on Sep 21, 2018
                          #821 references and aims to solve this issue.
                          Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
                          Perf tests results before and after the change are shown below:
                          Before the change:
                          BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                          TypeMethodMeanErrorStdDev
                          AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
                          NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
                          SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
                          AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
                          NativePerformanceTestsAddU330.1 us3.585 us3.178 us
                          SsePerformanceTestsAddU325.6 us6.883 us7.926 us
                          After the change:
                          BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                          TypeMethodMeanErrorStdDev
                          AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
                          NativePerformanceTestsSumU281.6 us5.261 us4.921 us
                          SsePerformanceTestsSumU294.1 us2.080 us1.946 us
                          AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
                          NativePerformanceTestsAddU335.1 us3.053 us2.707 us
                          SsePerformanceTestsAddU345.0 us2.155 us1.800 us
                          Both SSE and AVX implementations are slower by 10-20% after this change.
                          In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
                          var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

                          Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
                          cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
                          Metadata
                          Metadata
                          Assignees
                          No one assigned
                            Labels
                            P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                            Type
                            No type
                            Projects
                            No projects
                              Milestone
                              No milestone
                              Relationships
                              None yet
                              Development
                              No branches or pull requests
                              Issue actions
                              
, '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); }
})();
})();

                              Skip to content
                              Avoids pointer overflow in bound checking of SSE/AVX intrinsics #980
                              Open
                              Open
                              Avoids pointer overflow in bound checking of SSE/AVX intrinsics#980
                              Labels
                              P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                              Description
                              @briancylui
                              briancylui
                              opened on Sep 21, 2018
                              #821 references and aims to solve this issue.
                              Suggested by @ahsonkhan to avoid integer overflow in bound checking inside SSE/AVX intrinsics implementation, i.e. change all while (pCurrent + 8 OR 4 <= pEnd) into while (pEnd - pCurrent >= 8 OR 4).
                              Perf tests results before and after the change are shown below:
                              Before the change:
                              BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                              TypeMethodMeanErrorStdDev
                              AvxPerformanceTestsSumU159.4 us1.104 us0.9784 us
                              NativePerformanceTestsSumU283.5 us5.492 us4.8687 us
                              SsePerformanceTestsSumU281.2 us1.472 us1.3045 us
                              AvxPerformanceTestsAddU276.1 us3.018 us2.520 us
                              NativePerformanceTestsAddU330.1 us3.585 us3.178 us
                              SsePerformanceTestsAddU325.6 us6.883 us7.926 us
                              After the change:
                              BenchmarkDotNet=v0.11.1, OS=Windows 10.0.17134.228 (1803/April2018Update/Redstone4)
Intel Core i7-7700 CPU 3.60GHz (Kaby Lake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=3.0.100-alpha1-20180720-2
[Host] : .NET Core 3.0.0-preview1-26710-03 (CoreCLR 4.6.26710.05, CoreFX 4.6.26708.04), 64bit RyuJIT
Toolchain=InProcessToolchain
                              TypeMethodMeanErrorStdDev
                              AvxPerformanceTestsSumU183.5 us3.621 us3.023 us
                              NativePerformanceTestsSumU281.6 us5.261 us4.921 us
                              SsePerformanceTestsSumU294.1 us2.080 us1.946 us
                              AvxPerformanceTestsAddU296.3 us5.185 us4.850 us
                              NativePerformanceTestsAddU335.1 us3.053 us2.707 us
                              SsePerformanceTestsAddU345.0 us2.155 us1.800 us
                              Both SSE and AVX implementations are slower by 10-20% after this change.
                              In my opinion, after seeing the perf results, I may not recommend merging this PR. I may wait until the alternative suggested by @tannergooding in an earlier PR review has been implemented (2nd item under "Functionality" in briancylui#2):
                              var remainder = count % elementsPerIteration;
float* pEnd = pdst + (count - remainder);
while (pDstCurrent < pEnd)
{ … }

                              Another question I have is: would pDstCurrent + 8 OR 4 ever have the possibility to result in integer overflow? According to my knowledge, pEnd is initialized as pDstCurrent + count, and there are Contract.Asserts in the wrapper class to check that count does not exceed the original array length. I'm not sure, and am open to any PR comments and advice.
                              cc: @danmosemsft @eerhardt@tannergooding@ahsonkhan@markusweimer
                              Metadata
                              Metadata
                              Assignees
                              No one assigned
                                Labels
                                P2Priority of the issue for triage purpose: Needs to be fixed at some point.
                                Type
                                No type
                                Projects
                                No projects
                                  Milestone
                                  No milestone
                                  Relationships
                                  None yet
                                  Development
                                  No branches or pull requests
                                  Issue actions