[llvm] [X86] Support promoted ENQCMD, KEYLOCKER and USER-MSR instructions (PR #77293)

[Shengchen Kan via llvm-commits]

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@@ -436,21 +436,38 @@ def WRMSRLIST : I<0x01, MRM_C6, (outs), (ins), "wrmsrlist", []>, TB, XS;
 def RDMSRLIST : I<0x01, MRM_C6, (outs), (ins), "rdmsrlist", []>, TB, XD;
 }
 
-let Predicates = [HasUSERMSR], mayLoad = 1 in {
-  def URDMSRrr : I<0xf8, MRMSrcReg, (outs GR64:$dst), (ins GR64:$src),
-                "urdmsr\t{$src, $dst|$dst, $src}",
-                [(set GR64:$dst, (int_x86_urdmsr GR64:$src))]>, T8, XD;
-  def URDMSRri : Ii32<0xf8, MRM0r, (outs GR64:$dst), (ins i64i32imm:$imm),
-                "urdmsr\t{$imm, $dst|$dst, $imm}",
-                [(set GR64:$dst, (int_x86_urdmsr i64immSExt32_su:$imm))]>, T_MAP7, XD, VEX;
+multiclass Urdwrmsr_rr<string suffix> {
+  let mayLoad = 1 in
+    def URDMSRrr#suffix : I<0xf8, MRMSrcReg, (outs GR64:$dst), (ins GR64:$src),
+                            "urdmsr\t{$src, $dst|$dst, $src}",
+                            [(set GR64:$dst, (int_x86_urdmsr GR64:$src))]>, XD, NoCD8;
+  let mayStore = 1 in
+    def UWRMSRrr#suffix  : I<0xf8, MRMSrcReg, (outs), (ins GR64:$src1, GR64:$src2),
+                             "uwrmsr\t{$src2, $src1|$src1, $src2}",
+                             [(int_x86_uwrmsr GR64:$src1, GR64:$src2)]>, XS, NoCD8;
 }
-let Predicates = [HasUSERMSR], mayStore = 1 in {
-  def UWRMSRrr : I<0xf8, MRMSrcReg, (outs), (ins GR64:$src1, GR64:$src2),
-                "uwrmsr\t{$src2, $src1|$src1, $src2}",
-                [(int_x86_uwrmsr GR64:$src1, GR64:$src2)]>, T8, XS;
-  def UWRMSRir : Ii32<0xf8, MRM0r, (outs), (ins GR64:$src, i64i32imm:$imm),
-                "uwrmsr\t{$src, $imm|$imm, $src}",
-                [(int_x86_uwrmsr i64immSExt32_su:$imm, GR64:$src)]>, T_MAP7, XS, VEX;
+
+multiclass Urdwrmsr_ri<string suffix> {
+  let mayLoad = 1 in
+    def URDMSRri#suffix  : Ii32<0xf8, MRM0r, (outs GR64:$dst), (ins i64i32imm:$imm),
+                                "urdmsr\t{$imm, $dst|$dst, $imm}",
+                                [(set GR64:$dst, (int_x86_urdmsr i64immSExt32_su:$imm))]>,
+                           T_MAP7, XD, NoCD8;
+  let mayStore = 1 in
+    def UWRMSRir#suffix  : Ii32<0xf8, MRM0r, (outs), (ins GR64:$src, i64i32imm:$imm),
+                                "uwrmsr\t{$src, $imm|$imm, $src}",
+                                [(int_x86_uwrmsr i64immSExt32_su:$imm, GR64:$src)]>,
+                           T_MAP7, XS, NoCD8;
+}
+
+let Predicates = [HasUSERMSR, NoEGPR] in {
+  defm "" : Urdwrmsr_rr<"">, T8;
+  defm "" : Urdwrmsr_ri<"">, VEX;
+}
+
+let Predicates = [HasUSERMSR, HasEGPR, In64BitMode], mayLoad = 1 in {
----------------
KanRobert wrote:

mayLoad = 1 should be redundant.

https://github.com/llvm/llvm-project/pull/77293