[llvm] [MachineVerifier] Query TargetInstrInfo for PHI nodes. (PR #110507)

[Vyacheslav Levytskyy via llvm-commits]

Nathan =?utf-8?q?Gau=C3=ABr?= <brioche at google.com>,
Nathan =?utf-8?q?Gau=C3=ABr?= <brioche at google.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/110507 at github.com>


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@@ -2278,6 +2278,32 @@ class TargetInstrInfo : public MCInstrInfo {
     llvm_unreachable("unknown number of operands necessary");
   }
 
+  // This this instruction a PHI node.
+  // This function should be favored over MI.isPHI() as it allows backends to
+  // define additional PHI instructions.
+  virtual bool isPhiInstr(const MachineInstr &MI) const {
+    return MI.getOpcode() == TargetOpcode::G_PHI ||
+           MI.getOpcode() == TargetOpcode::PHI;
+  }
+
+  // Returns the number of [Value, Src] pairs this phi instruction has.
+  // Only valid to call on a phi node.
+  virtual unsigned getNumPhiIncomingPair(const MachineInstr &MI) const {
+    assert(isPhiInstr(MI));
+    // G_PHI/PHI only have a single operand before the pairs. 2 Operands per
+    // pair.
+    return (MI.getNumOperands() - 1) / 2;
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VyacheslavLevytskyy wrote:

or `>> 1` ?

https://github.com/llvm/llvm-project/pull/110507