Skip to content
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

Jump to bottom

[release/8.0] Check if loop body occured before loopTop and if so unmark alignment #91918

Merged
merged 4 commits into from
Sep 18, 2023
Merged

[release/8.0] Check if loop body occured before loopTop and if so unmark alignment #91918

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2264fb6
Check if loop body occured before loopTop"
kunalspathak Sep 10, 2023
34f74f5
Merge remote-tracking branch 'origin/release/8.0' into pr-91854
kunalspathak Sep 12, 2023
db15d80
Check if bbNatLoopNum is not NOT_IN_LOOP
kunalspathak Sep 15, 2023
798f438
review feedback
kunalspathak Sep 15, 2023
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
34 changes: 31 additions & 3 deletions src/coreclr/jit/compiler.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5282,6 +5282,13 @@ PhaseStatus Compiler::placeLoopAlignInstructions()
weight_t minBlockSoFar = BB_MAX_WEIGHT;
BasicBlock* bbHavingAlign = nullptr;
BasicBlock::loopNumber currentAlignedLoopNum = BasicBlock::NOT_IN_LOOP;
bool visitedLoopNum[BasicBlock::MAX_LOOP_NUM];
memset(visitedLoopNum, false, sizeof(visitedLoopNum));

#ifdef DEBUG
unsigned visitedBlockForLoopNum[BasicBlock::MAX_LOOP_NUM];
memset(visitedBlockForLoopNum, 0, sizeof(visitedBlockForLoopNum));
#endif

if ((fgFirstBB != nullptr) && fgFirstBB->isLoopAlign())
{
Expand All @@ -5304,7 +5311,7 @@ PhaseStatus Compiler::placeLoopAlignInstructions()
}
}

// If there is a unconditional jump (which is not part of callf/always pair)
// If there is an unconditional jump (which is not part of callf/always pair)
if (opts.compJitHideAlignBehindJmp && (block->bbJumpKind == BBJ_ALWAYS) && !block->isBBCallAlwaysPairTail())
{
// Track the lower weight blocks
Expand Down Expand Up @@ -5358,12 +5365,19 @@ PhaseStatus Compiler::placeLoopAlignInstructions()
madeChanges = true;
unmarkedLoopAlign = true;
}
else if ((block->bbNatLoopNum != BasicBlock::NOT_IN_LOOP) && (block->bbNatLoopNum == loopTop->bbNatLoopNum))
else if ((loopTop->bbNatLoopNum != BasicBlock::NOT_IN_LOOP) && visitedLoopNum[loopTop->bbNatLoopNum])
{
#ifdef DEBUG
char buffer[100];
sprintf_s(buffer, 100, "loop block " FMT_BB " appears before top of loop",
visitedBlockForLoopNum[loopTop->bbNatLoopNum]);
#endif

// In some odd cases we may see blocks within the loop before we see the
// top block of the loop. Just bail on aligning such loops.
//
loopTop->unmarkLoopAlign(this DEBUG_ARG("loop block appears before top of loop"));

loopTop->unmarkLoopAlign(this DEBUG_ARG(buffer));
madeChanges = true;
unmarkedLoopAlign = true;
}
Expand Down Expand Up @@ -5398,6 +5412,20 @@ PhaseStatus Compiler::placeLoopAlignInstructions()
break;
}
}

if (block->bbNatLoopNum != BasicBlock::NOT_IN_LOOP)
{
#ifdef DEBUG
if (!visitedLoopNum[block->bbNatLoopNum])
{
// Record the first block for which bbNatLoopNum was seen for
// debugging purpose.
visitedBlockForLoopNum[block->bbNatLoopNum] = block->bbNum;
}
#endif
// If this block is part of loop, mark the loopNum as visited.
visitedLoopNum[block->bbNatLoopNum] = true;
}
}

assert(loopsToProcess == 0);
Expand Down
Loading