https://gcc.gnu.org/bugzilla/show_bug.cgi?id=76783
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Actually it's folding during late CCP somehow. Mine. Visiting PHI node: u_6 = PHI <{ 0, 0, 0, 0 }(2), { 0, 1, 0, 0 }(3)> Argument #0 (2 -> 4 executable) { 0, 0, 0, 0 } Value: CONSTANT { 0, 0, 0, 0 } Argument #1 (3 -> 4 not executable) PHI node value: CONSTANT { 0, 0, 0, 0 } Lattice value changed to CONSTANT { 0, 0, 0, 0 }. Adding SSA edges to worklist. ... Visiting statement: _1 = {_10, _13, _16, _19}; which is likely CONSTANT Lattice value changed to VARYING. Adding SSA edges to worklist. Visiting statement: _5 = BIT_FIELD_REF <_1, 128, 128>; which is likely CONSTANT Applying pattern match.pd:3444, gimple-match.c:62758 Match-and-simplified BIT_FIELD_REF <_1, 128, 128> to _13 Lattice value changed to CONSTANT _11. Adding SSA edges to worklist. marking stmt to be not simulated again somehow it looks up a SSA name that is not final yet.