Skip to content

JIT: Remove tailcall "has GC safe point" assert #123489

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
jakobbotsch merged 6 commits into from
Jan 28, 2026
Merged

JIT: Remove tailcall "has GC safe point" assert #123489

Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
4e01e9a
JIT: Improve precision of tailcall "has GC safe point" assert
jakobbotsch Jan 22, 2026
1719c54
Clean up a comment
jakobbotsch Jan 22, 2026
2001595
Apply suggestion from @jakobbotsch
jakobbotsch Jan 23, 2026
3950e24
Remove assert
jakobbotsch Jan 26, 2026
833bdb6
Run jit-format
jakobbotsch Jan 26, 2026
2f21309
Apply suggestion from @jakobbotsch
jakobbotsch Jan 27, 2026
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
20 changes: 0 additions & 20 deletions src/coreclr/jit/lower.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3206,20 +3206,6 @@ void Lowering::LowerFastTailCall(GenTreeCall* call)
// We expect to see a call that meets the following conditions
assert(call->IsFastTailCall());

// VM cannot use return address hijacking when A() and B() tail call each
// other in mutual recursion. Therefore, this block is reachable through
// a GC-safe point or the whole method is marked as fully interruptible.
//
// TODO-Cleanup:
// optReachWithoutCall() depends on the fact that loop headers blocks
// will have a block number > fgLastBB. These loop headers gets added
// after dominator computation and get skipped by OptReachWithoutCall().
// The below condition cannot be asserted in lower because fgSimpleLowering()
// can add a new basic block for range check failure which becomes
// fgLastBB with block number > loop header block number.
// assert(comp->compCurBB->HasFlag(BBF_GC_SAFE_POINT) ||
// !comp->optReachWithoutCall(comp->fgFirstBB, comp->compCurBB) || comp->GetInterruptible());

// If PInvokes are in-lined, we have to remember to execute PInvoke method epilog anywhere that
// a method returns. This is a case of caller method has both PInvokes and tail calls.
if (comp->compMethodRequiresPInvokeFrame())
Expand Down Expand Up @@ -3522,12 +3508,6 @@ GenTree* Lowering::LowerTailCallViaJitHelper(GenTreeCall* call, GenTree* callTar
assert(call->IsTailCallViaJitHelper());
assert(callTarget != nullptr);

// The TailCall helper call never returns to the caller and is not GC interruptible.
// Therefore the block containing the tail call should be a GC safe point to avoid
// GC starvation. It is legal for the block to be unmarked iff the entry block is a
// GC safe point, as the entry block trivially dominates every reachable block.
assert(comp->compCurBB->HasFlag(BBF_GC_SAFE_POINT) || comp->fgFirstBB->HasFlag(BBF_GC_SAFE_POINT));

// If PInvokes are in-lined, we have to remember to execute PInvoke method epilog anywhere that
// a method returns. This is a case of caller method has both PInvokes and tail calls.
if (comp->compMethodRequiresPInvokeFrame())
Expand Down
Loading