https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100373
--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:b5254d6b75fe6be669396cd1261f1cba829cc451 commit r12-558-gb5254d6b75fe6be669396cd1261f1cba829cc451 Author: Richard Biener <rguent...@suse.de> Date: Wed May 5 10:15:27 2021 +0200 ipa/100373 - fix emutls lowering compare-debug issue emutls figured that tls uses in debug-insns need lowering but that obviously has effects on code-generation as can be seen in the following IL diff with the new testcase: <bb 2> [local count: 1073741824]: - a = 0; + # DEBUG BEGIN_STMT _4 = __builtin___emutls_get_address (&__emutls_v.b); + # DEBUG D#1 => *_4 + # DEBUG d => (long int) D#1 + # DEBUG BEGIN_STMT + a = 0; + # DEBUG BEGIN_STMT *_4 = 0; return; where it figured the debug use of b in the original <bb 2> [local count: 1073741824]: # DEBUG BEGIN_STMT # DEBUG D#1 => b # DEBUG d => (long int) D#1 # DEBUG BEGIN_STMT a = 0; needs lowering (it maybe does when we want to produce perfect debug but that's just bad luck). The following patch fixes this by avoiding to create a new emutls address when visiting debug stmts and instead resets them. Another option might be to simply not lower debug stmt uses but I have no way to verify actual debug info for this. 2021-05-05 Richard Biener <rguent...@suse.de> PR ipa/100373 * tree-emutls.c (gen_emutls_addr): Pass in whether we're dealing with a debug use and only query existing addresses if so. (lower_emutls_1): Avoid splitting out addresses for debug stmts, reset the debug stmt when we fail to find existing lowered addresses. (lower_emutls_phi_arg): Set wi.stmt. * gcc.dg/pr100373.c: New testcase.
