[llvm] [X86][MC] Support Enc/Dec for EGPR for promoted INVPCID instruction (PR #74548)

[Phoebe Wang via llvm-commits]

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@@ -679,6 +679,11 @@ def INVPCID32 : I<0x82, MRMSrcMem, (outs), (ins GR32:$src1, i128mem:$src2),
 def INVPCID64 : I<0x82, MRMSrcMem, (outs), (ins GR64:$src1, i128mem:$src2),
                   "invpcid\t{$src2, $src1|$src1, $src2}", []>, T8PD,
                   Requires<[In64BitMode, HasINVPCID]>;
+
+let CD8_Scale = 0 in
+def INVPCID64_EVEX : I<0xF2, MRMSrcMem, (outs), (ins GR64:$src1, i128mem:$src2),
+                       "invpcid\t{$src2, $src1|$src1, $src2}", []>,
+                     EVEX, T_MAP4XS, Requires<[In64BitMode, HasINVPCID]>;
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phoebewang wrote:

Should we refactor the `EVEX` to e.g. `EVEX_NoCD8` to avoid `let CD8_Scale = 0 in` repeatedly?

https://github.com/llvm/llvm-project/pull/74548