https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110557
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Xi Ruoyao <xry...@gcc.gnu.org>: https://gcc.gnu.org/g:63ae6bc60c0f67fb2791991bf4b6e7e0a907d420 commit r14-2407-g63ae6bc60c0f67fb2791991bf4b6e7e0a907d420 Author: Xi Ruoyao <xry...@xry111.site> Date: Thu Jul 6 23:08:57 2023 +0800 vect: Fix vectorized BIT_FIELD_REF for signed bit-fields [PR110557] If a bit-field is signed and it's wider than the output type, we must ensure the extracted result sign-extended. But this was not handled correctly. For example: int x : 8; long y : 55; bool z : 1; The vectorized extraction of y was: vect__ifc__49.29_110 = MEM <vector(2) long unsigned int> [(struct Item *)vectp_a.27_108]; vect_patt_38.30_112 = vect__ifc__49.29_110 & { 9223372036854775552, 9223372036854775552 }; vect_patt_39.31_113 = vect_patt_38.30_112 >> 8; vect_patt_40.32_114 = VIEW_CONVERT_EXPR<vector(2) long int>(vect_patt_39.31_113); This is obviously incorrect. This pach has implemented it as: vect__ifc__25.16_62 = MEM <vector(2) long unsigned int> [(struct Item *)vectp_a.14_60]; vect_patt_31.17_63 = VIEW_CONVERT_EXPR<vector(2) long int>(vect__ifc__25.16_62); vect_patt_32.18_64 = vect_patt_31.17_63 << 1; vect_patt_33.19_65 = vect_patt_32.18_64 >> 9; gcc/ChangeLog: PR tree-optimization/110557 * tree-vect-patterns.cc (vect_recog_bitfield_ref_pattern): Ensure the output sign-extended if necessary. gcc/testsuite/ChangeLog: PR tree-optimization/110557 * g++.dg/vect/pr110557.cc: New test.
