JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
amanasifkhalid merged 6 commits into from
May 21, 2024
Merged

JIT: Move backward jumps to before their successors after RPO-based layout #102461

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
893c9a4
wip
amanasifkhalid May 20, 2024
3d31c8b
Add fgMoveBlocksToHottestSuccessors
amanasifkhalid May 20, 2024
3ae278f
Add comment
amanasifkhalid May 20, 2024
f9d81a9
Add loop head exception
amanasifkhalid May 20, 2024
a5b9c21
Revert "Add loop head exception"
amanasifkhalid May 20, 2024
608f1bd
Only move unconditional backward jumps
amanasifkhalid May 20, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions src/coreclr/jit/compiler.h
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
void fgDoReversePostOrderLayout();
void fgMoveColdBlocks();

template <bool hasEH>
void fgMoveBackwardJumpsToSuccessors();

bool fgFuncletsAreCold();

PhaseStatus fgDetermineFirstColdBlock();
Expand Down
2 changes: 1 addition & 1 deletion src/coreclr/jit/fgbasic.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
*/
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
if (insertBeforeBlk->IsFirst())
if (fgFirstBB == insertBeforeBlk)
{
newBlk->SetNext(fgFirstBB);

Expand Down
104 changes: 104 additions & 0 deletions src/coreclr/jit/fgopt.cpp
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
if (verbose)
{
printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

printf("\nInitial BasicBlocks");
fgDispBasicBlocks(verboseTrees);
printf("\n");
}
#endif // DEBUG

EnsureBasicBlockEpoch();
BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

// Don't try to move the first block.
// Also, if we have a funclet region, don't bother reordering anything in it.
//
BasicBlock* next;
for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
{
next = block->Next();
BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

// Don't bother trying to move cold blocks
//
if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
{
continue;
}

// We will consider moving only backward jumps
//
BasicBlock* const target = block->GetTarget();
if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
{
continue;
}

if (hasEH)
{
// Don't move blocks in different EH regions
//
if (!BasicBlock::sameEHRegion(block, target))
{
continue;
}

// block and target are in the same try/handler regions, and target is behind block,
// so block cannot possibly be the start of the region.
//
assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

// Don't change the entry block of an EH region
//
if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
{
continue;
}
}

// We don't want to change the first block, so if the jump target is the first block,
// don't try moving this block before it.
// Also, if the target is cold, don't bother moving this block up to it.
//
if (target->IsFirst() || target->isRunRarely())
{
continue;
}

// If moving block will break up existing fallthrough behavior into target, make sure it's worth it
//
FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
if ((fallthroughEdge != nullptr) &&
(fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
{
continue;
}

// Move block to before target
//
fgUnlinkBlock(block);
fgInsertBBbefore(target, block);
}
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
fgInsertBBafter(block, blockToMove);
}

// The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
// In particular, it may place the loop head after the loop exit, creating unnecessary branches.
// Fix this by moving unconditional backward jumps up to their targets,
// increasing the likelihood that the loop exit block is the last block in the loop.
//
fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

return;
}

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
}
}

fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

// Fix up call-finally pairs
//
for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down
, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down

, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down

, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down

, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down

, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down

, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down

, '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
JIT: Move backward jumps to before their successors after RPO-based layout#102461

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

 Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

amanasifkhalid
merged 6 commits into

from

May 21, 2024
 Merged


JIT: Move backward jumps to before their successors after RPO-based layout
#102461
Show file tree
Hide file tree
 Changes from all commits
Commits

Show all changes


6 commits


Select commit
Hold shift + click to select a range
893c9a4

wip


amanasifkhalid May 20, 2024
3d31c8b

Add fgMoveBlocksToHottestSuccessors


amanasifkhalid May 20, 2024
3ae278f

Add comment


amanasifkhalid May 20, 2024
f9d81a9

Add loop head exception


amanasifkhalid May 20, 2024
a5b9c21

Revert "Add loop head exception"


amanasifkhalid May 20, 2024
608f1bd

Only move unconditional backward jumps


amanasifkhalid May 20, 2024

File filter

Filter by extension
Filter by extension
Conversations

Failed to load comments. 
Loading
Jump to

Jump to file


Failed to load files. 
Loading
 Diff view

 Diff view


3 changes: 3 additions & 0 deletions
src/coreclr/jit/compiler.h

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6096,6 +6096,9 @@ class Compiler
 void fgDoReversePostOrderLayout();
 void fgMoveColdBlocks();

 template <bool hasEH>
 void fgMoveBackwardJumpsToSuccessors();

 bool fgFuncletsAreCold();

 PhaseStatus fgDetermineFirstColdBlock();
Expand Down

2 changes: 1 addition & 1 deletion
src/coreclr/jit/fgbasic.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -6154,7 +6154,7 @@ BasicBlock* Compiler::fgNewBBFromTreeAfter(
 */
void Compiler::fgInsertBBbefore(BasicBlock* insertBeforeBlk, BasicBlock* newBlk)
{
 if (insertBeforeBlk->IsFirst())
 if (fgFirstBB == insertBeforeBlk)
 {
 newBlk->SetNext(fgFirstBB);

Expand Down

104 changes: 104 additions & 0 deletions
src/coreclr/jit/fgopt.cpp

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -4535,6 +4535,101 @@ bool Compiler::fgReorderBlocks(bool useProfile)
#pragma warning(pop)
#endif

//-----------------------------------------------------------------------------
// fgMoveBackwardJumpsToSuccessors: Try to move backward unconditional jumps to fall into their successors.
//
// Template parameters:
// hasEH - If true, method has EH regions, so check that we don't try to move blocks in different regions
//
template <bool hasEH>
void Compiler::fgMoveBackwardJumpsToSuccessors()
{
#ifdef DEBUG
 if (verbose)
 {
 printf("*************** In fgMoveBackwardJumpsToSuccessors()\n");

 printf("\nInitial BasicBlocks");
 fgDispBasicBlocks(verboseTrees);
 printf("\n");
 }
#endif // DEBUG

 EnsureBasicBlockEpoch();
 BlockSet visitedBlocks(BlockSetOps::MakeEmpty(this));
 BlockSetOps::AddElemD(this, visitedBlocks, fgFirstBB->bbNum);

 // Don't try to move the first block.
 // Also, if we have a funclet region, don't bother reordering anything in it.
 //
 BasicBlock* next;
 for (BasicBlock* block = fgFirstBB->Next(); block != fgFirstFuncletBB; block = next)
 {
 next = block->Next();
 BlockSetOps::AddElemD(this, visitedBlocks, block->bbNum);

 // Don't bother trying to move cold blocks
 //
 if (!block->KindIs(BBJ_ALWAYS) || block->isRunRarely())
 {
 continue;
 }

 // We will consider moving only backward jumps
 //
 BasicBlock* const target = block->GetTarget();
 if ((block == target) || !BlockSetOps::IsMember(this, visitedBlocks, target->bbNum))
 {
 continue;
 }

 if (hasEH)
 {
 // Don't move blocks in different EH regions
 //
 if (!BasicBlock::sameEHRegion(block, target))
 {
 continue;
 }

 // block and target are in the same try/handler regions, and target is behind block,
 // so block cannot possibly be the start of the region.
 //
 assert(!bbIsTryBeg(block) && !bbIsHandlerBeg(block));

 // Don't change the entry block of an EH region
 //
 if (bbIsTryBeg(target) || bbIsHandlerBeg(target))
 {
 continue;
 }
 }

 // We don't want to change the first block, so if the jump target is the first block,
 // don't try moving this block before it.
 // Also, if the target is cold, don't bother moving this block up to it.
 //
 if (target->IsFirst() || target->isRunRarely())
 {
 continue;
 }

 // If moving block will break up existing fallthrough behavior into target, make sure it's worth it
 //
 FlowEdge* const fallthroughEdge = fgGetPredForBlock(target, target->Prev());
 if ((fallthroughEdge != nullptr) &&
 (fallthroughEdge->getLikelyWeight() >= block->GetTargetEdge()->getLikelyWeight()))
 {
 continue;
 }

 // Move block to before target
 //
 fgUnlinkBlock(block);
 fgInsertBBbefore(target, block);
 }
}

//-----------------------------------------------------------------------------
// fgDoReversePostOrderLayout: Reorder blocks using a greedy RPO traversal.
//
Expand DownExpand Up@@ -4567,6 +4662,13 @@ void Compiler::fgDoReversePostOrderLayout()
 fgInsertBBafter(block, blockToMove);
 }

 // The RPO established a good base layout, but in some cases, it might produce a subpar layout for loops.
 // In particular, it may place the loop head after the loop exit, creating unnecessary branches.
 // Fix this by moving unconditional backward jumps up to their targets,
 // increasing the likelihood that the loop exit block is the last block in the loop.
 //
 fgMoveBackwardJumpsToSuccessors</* hasEH */ false>();

 return;
 }

Expand DownExpand Up@@ -4645,6 +4747,8 @@ void Compiler::fgDoReversePostOrderLayout()
 }
 }

 fgMoveBackwardJumpsToSuccessors</* hasEH */ true>();

 // Fix up call-finally pairs
 //
 for (int i = 0; i < callFinallyPairs.Height(); i++)
Expand Down