Skip to content

Fix Chebyshev solver: zero x in solve_init when xIsZero=true #372

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

Open
markadams wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Fix Chebyshev solver: zero x in solve_init when xIsZero=true #372

Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
9 changes: 9 additions & 0 deletions src/solvers/cheb_solver.cu
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -282,6 +282,15 @@ Chebyshev_Solver<T_Config>::solve_init( VVector &b, VVector &x, bool xIsZero )
int offset, size;
A.getOffsetAndSizeForView(A.getViewExterior(), &offset, &size);

// Ensure x is actually zero when xIsZero is claimed.
// Callers (e.g. PCG) pass xIsZero=true but may not have zeroed the buffer.
// Without this, solve_iteration's "x += gamma*p" accumulates onto stale data
// from the previous outer iteration, causing divergence.
if (xIsZero)
{
fill(x, types::util<ValueTypeB>::get_zero());
}

// Run one iteration of preconditioner with zero initial guess
if (no_preconditioner)
{
Expand Down