https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110278
Bug ID: 110278 Summary: [14 Regression] FAIL: gcc.dg/tree-ssa/pr103257-1.c scan-tree-dump-times optimized "link_error" 0 from r14-1880-g827e208fa64771 Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: rguenth at gcc dot gnu.org Target Milestone: --- r14-1880-g827e208fa64771 causes FAIL: gcc.dg/tree-ssa/pr103257-1.c scan-tree-dump-times optimized "link_error" 0 because we now fold more in .original: - if (a ((unsigned int) ((0, 1) && b != 0) > b, (int) (short int) c) != 0) + if (a ((unsigned int) (b != 0) > b, (int) (short int) c) != 0) the call to link_error was optimized away in threadfull1 before this change, after the change code is straight-line and no jump threading opportunity is realized. Before we enter threadfull1 with <bb 2> [local count: 1073741824]: c.0_1 = c; b.2_2 = b; if (b.2_2 != 0) goto <bb 4>; [50.00%] else goto <bb 3>; [50.00%] <bb 3> [local count: 536870913]: <bb 4> [local count: 1073741824]: # iftmp.1_5 = PHI <1(2), 0(3)> iftmp.3_3 = (unsigned int) iftmp.1_5; _4 = b.2_2 < iftmp.3_3; e.5_10 = (unsigned short) _4; f.6_11 = (unsigned short) c.0_1; _12 = e.5_10 * f.6_11; if (_12 != 0) goto <bb 5>; [33.00%] else goto <bb 6>; [67.00%] <bb 5> [local count: 354334800]: link_error (); <bb 6> [local count: 1073741824]: c = 0; return 0; but afterwards the b != 0 condition is in straight-line code: <bb 2> [local count: 1073741824]: c.0_1 = c; b.1_2 = b; _3 = b.1_2 != 0; _4 = (unsigned int) _3; _5 = b.1_2 < _4; e.3_10 = (unsigned short) _5; f.4_11 = (unsigned short) c.0_1; _12 = e.3_10 * f.4_11; if (_12 != 0) goto <bb 3>; [33.00%] else goto <bb 4>; [67.00%] <bb 3> [local count: 354334800]: link_error (); <bb 4> [local count: 1073741824]: c = 0; return 0;