[GlobalISel] Don't RegBankSelect target-specific instructions.

They don't have types and should be using register classes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277447 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetOpcodes.h

@@ -32,6 +32,11 @@ static inline bool isPreISelGenericOpcode(unsigned Opcode) {
   return Opcode >= TargetOpcode::PRE_ISEL_GENERIC_OPCODE_START &&
          Opcode <= TargetOpcode::PRE_ISEL_GENERIC_OPCODE_END;
 }
+
+/// Check whether the given Opcode is a target-specific opcode.
+static inline bool isTargetSpecificOpcode(unsigned Opcode) {
+  return Opcode > TargetOpcode::PRE_ISEL_GENERIC_OPCODE_END;
+}
 } // end namespace llvm
 
 #endif

lib/CodeGen/GlobalISel/RegBankSelect.cpp

@@ -554,7 +554,13 @@ bool RegBankSelect::runOnMachineFunction(MachineFunction &MF) {
          MII != End;) {
       // MI might be invalidated by the assignment, so move the
       // iterator before hand.
-      assignInstr(*MII++);
+      MachineInstr &MI = *MII++;
+
+      // Ignore target-specific instructions: they should use proper regclasses.
+      if (isTargetSpecificOpcode(MI.getOpcode()))
+        continue;
+
+      assignInstr(MI);
     }
   }
   OptMode = SaveOptMode;

test/CodeGen/AArch64/GlobalISel/arm64-regbankselect.mir

@@ -54,6 +54,8 @@
   entry:
     ret void
   }
+
+  define void @ignoreTargetSpecificInst() { ret void }
 ...
 
 ---
@@ -327,3 +329,28 @@ body: |
     %1(64) = COPY %x1
     %2(64) = G_OR <2 x s32> %0, %1
 ...
+
+---
+# CHECK-LABEL: name: ignoreTargetSpecificInst
+name:            ignoreTargetSpecificInst
+isSSA:           true
+# CHECK:      registers:
+# CHECK-NEXT:  - { id: 0, class: gpr64 }
+# CHECK-NEXT:  - { id: 1, class: gpr64 }
+registers:
+  - { id: 0, class: gpr64 }
+  - { id: 1, class: gpr64 }
+body: |
+  bb.0:
+    liveins: %x0
+
+    ; CHECK: %0 = COPY %x0
+    ; CHECK-NEXT: %1 = ADDXrr %0, %0
+    ; CHECK-NEXT: %x0 = COPY %1
+    ; CHECK-NEXT: RET_ReallyLR implicit %x0
+
+    %0 = COPY %x0
+    %1 = ADDXrr %0, %0
+    %x0 = COPY %1
+    RET_ReallyLR implicit %x0
+...