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From: "ktkachov at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/110039] New: FAIL: gcc.target/aarch64/rev16_2.c scan-assembler-times rev16\\tw[0-9]+ 2 Date: Tue, 30 May 2023 12:49:21 +0000 [thread overview] Message-ID: <bug-110039-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110039 Bug ID: 110039 Summary: FAIL: gcc.target/aarch64/rev16_2.c scan-assembler-times rev16\\tw[0-9]+ 2 Product: gcc Version: 13.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: ktkachov at gcc dot gnu.org Target Milestone: --- Target: aarch64 I think after g:d8545fb2c71683f407bfd96706103297d4d6e27b the test regresses on aarch64. We now generate: __rev16_32_alt: rev w0, w0 ror w0, w0, 16 ret __rev16_32: rev w0, w0 ror w0, w0, 16 ret whereas before it was: __rev16_32_alt: rev16 w0, w0 ret __rev16_32: rev16 w0, w0 ret I think the GIMPLE at expand time is better and the RTL that it tries to match is simpler: Failed to match this instruction: (set (reg:SI 95) (rotate:SI (bswap:SI (reg:SI 96)) (const_int 16 [0x10]))) So maybe it's simply a matter of adding that pattern to aarch64.md. Anyway, filing this here to track the regression
next reply other threads:[~2023-05-30 12:49 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-05-30 12:49 ktkachov at gcc dot gnu.org [this message] 2023-05-30 12:49 ` [Bug target/110039] [14 Regression] " ktkachov at gcc dot gnu.org 2023-05-31 6:53 ` rsandifo at gcc dot gnu.org 2023-05-31 13:27 ` cvs-commit at gcc dot gnu.org 2023-05-31 13:27 ` clyon at gcc dot gnu.org
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