[PATCH] D59077: [X86] Correct scheduler information for rotate by constant for Haswell, Broadwell, and Skylake.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: RKSimon, andreadb.
Herald added a subscriber: gbedwell.
Herald added a project: LLVM.

Rotate with explicit immediate is a single uop from Haswell on. An immediate of 1 has a dependency on the previous writer of flags, but the other immediate values do not.

The implicit rotate by 1 instruction is 2 uops. But the flags are merged after the rotate uop so the data result does not see the flag dependency. But I don't think we have any way of modeling that.

RORX is 1 uop without the load. 2 uops with the load. We currently model these with WriteShift/WriteShiftLd.


Repository:
  rL LLVM

https://reviews.llvm.org/D59077

Files:
  lib/Target/X86/X86SchedBroadwell.td
  lib/Target/X86/X86SchedHaswell.td
  lib/Target/X86/X86SchedSkylakeClient.td
  lib/Target/X86/X86SchedSkylakeServer.td
  test/tools/llvm-mca/X86/Broadwell/resources-x86_64.s
  test/tools/llvm-mca/X86/Haswell/resources-x86_64.s
  test/tools/llvm-mca/X86/SkylakeClient/resources-x86_64.s
  test/tools/llvm-mca/X86/SkylakeServer/resources-x86_64.s

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