https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77403
Bug ID: 77403 Summary: [7 Regression] assemble failure of vinserti64x4 with -masm=intel Product: gcc Version: 7.0 Status: UNCONFIRMED Keywords: assemble-failure Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: zsojka at seznam dot cz Target Milestone: --- Host: x86_64-pc-linux-gnu Target: x86_64-pc-linux-gnu Build: x86_64-pc-linux-gnu Created attachment 39511 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39511&action=edit reduced testcase Output: $ x86_64-pc-linux-gnu-gcc -O -mavx512f -masm=intel testcase.c /tmp/cc6ywLFg.s: Assembler messages: /tmp/cc6ywLFg.s:44: Error: operand size mismatch for `vinserti64x4' $ grep vinserti64x4 testcase.s vinserti64x4 zmm0, zmm3, ymm0, $0x0 The correct form would be: vinserti64x4 zmm0, zmm3, ymm0, 0x0 gcc-6 produces correct assembly.