https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97456
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Martin Jambor <jamb...@gcc.gnu.org>: https://gcc.gnu.org/g:d99b9dea37adfb88de2af121d31eed1c06b174b4 commit r10-8945-gd99b9dea37adfb88de2af121d31eed1c06b174b4 Author: Martin Jambor <mjam...@suse.cz> Date: Mon Oct 19 19:21:10 2020 +0200 cplxlower: Avoid a transform when looking at a default definition In PR 97456, IPA-SRA triggers a bug in tree-complex.c where it converts: <bb 2> a$_M_value_21 = COMPLEX_EXPR <ISRA.18_10(D), ISRA.18_10(D)>; (where ISRA.18 is IPA-SRA created PARM_DECL with DECL_IGNORED_P set, which is why it only happens with IPA-SRA) into: <bb 2> a$_M_value_21 = COMPLEX_EXPR <a$_M_value$real_10(D), a$_M_value$real_10(D)>; i.e. it replaces two uses of the parameter default-def with two uninitialized default-defs of a new variable - all in hope to produce code with better debug info. This patch fixes it by avoiding the transform when the SSA_NAME to be replaced is a default definition. gcc/ChangeLog: 2020-10-19 Martin Jambor <mjam...@suse.cz> PR tree-optimization/97456 * tree-complex.c (set_component_ssa_name): Do not replace ignored decl default definitions with new component vars. Reorder if conditions. gcc/testsuite/ChangeLog: 2020-10-19 Martin Jambor <mjam...@suse.cz> PR tree-optimization/97456 * gcc.dg/tree-ssa/pr97456.c: New test. (cherry picked from commit 619f91eaa8c8a50f1f9d3e7b96ee837037f0e806)
