https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107190
Bug ID: 107190 Summary: [aarch64] regression with optimization -fexpensive-optimizations Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: zhongyunde at huawei dot com Target Milestone: --- This case is simplify from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107090, and we can see that the codegen of function `test_m` has some regression with optimization -fexpensive-optimizations, https://gcc.godbolt.org/z/zbKrEox4j This is because the pass 208t.widening_mul is controlled by -fexpensive-optimizations (default on at -O3), it conversion ``` m_12 = m_9 + m1_10; if (m1_10 > m_12) ``` into ``` _17 = .ADD_OVERFLOW (m_9, m1_10); m_12 = REALPART_EXPR <_17>; _18 = IMAGPART_EXPR <_17>; if (_18 != 0)`` ```