https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94072
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:1aa22b1916a493ac46453d96e0c78ca47bcaeda3 commit r10-7301-g1aa22b1916a493ac46453d96e0c78ca47bcaeda3 Author: Richard Sandiford <richard.sandif...@arm.com> Date: Tue Mar 17 14:43:08 2020 +0000 c-family: Tighten vector handling in type_for_mode [PR94072] In this PR we had a 512-bit VECTOR_TYPE whose mode is XImode (an integer mode used for four 128-bit vectors). When trying to expand a zero constant for it, we hit code in expand_expr_real_1 that tries to use the associated integer type instead. The code used type_for_mode (XImode, 1) to get this integer type. However, the c-family implementation of type_for_mode checks for any registered built-in type that matches the mode and has the right signedness. This meant that it could return a built-in vector type when given an integer mode (particularly if, as here, the vector type isn't supported by the current subtarget and so TYPE_MODE != TYPE_MODE_RAW). The expand code would then cycle endlessly trying to use this "new" type instead of the original vector type. 2020-03-20 Richard Sandiford <richard.sandif...@arm.com> gcc/c-family/ PR middle-end/94072 * c-common.c (c_common_type_for_mode): Before using a registered built-in type, check that the vectorness of the type matches the vectorness of the mode. gcc/testsuite/ PR middle-end/94072 * gcc.target/aarch64/pr94072.c: New test.
