[PATCH] D88808: [X86] Defer the creation of LCMPXCHG16B_SAVE_RBX until finalize-isel

[Pengfei Wang via Phabricator via llvm-commits]

pengfei added a comment.

LGTM but I'd like to see if someone has objections.



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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:33785
+      BuildMI(*BB, MI, DL, TII->get(TargetOpcode::COPY), X86::RBX)
+          .addReg(MI.getOperand(X86::AddrNumOperands).getReg());
+      X86AddressMode AM = getAddressFromInstr(&MI, 0);
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Why don't we use the same form as line 33780?


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Comment at: llvm/lib/Target/X86/X86InstrCompiler.td:891
+      (ins i128mem:$ptr, GR64:$rbx_input),
+      "cmpxchg16b\t$ptr",
+      [(X86cas16 addr:$ptr, GR64:$rbx_input)]>;
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Maybe we can leave it "" since we don't use its assmebly.


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https://reviews.llvm.org/D88808