[llvm] [RISCV] Handle .vx/.vi pseudos in hasAllNBitUsers (PR #67419)

[Philip Reames via llvm-commits]

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@@ -77,6 +77,141 @@ FunctionPass *llvm::createRISCVOptWInstrsPass() {
   return new RISCVOptWInstrs();
 }
 
+static bool vectorPseudoHasAllNBitUsers(const MachineOperand &UserOp,
+                                        unsigned Bits) {
+  const MachineInstr &MI = *UserOp.getParent();
+  const RISCVVPseudosTable::PseudoInfo *PseudoInfo =
+      RISCVVPseudosTable::getPseudoInfo(MI.getOpcode());
+
+  if (!PseudoInfo)
+    return false;
+
+  const MCInstrDesc &MCID = MI.getDesc();
+  const uint64_t TSFlags = MI.getDesc().TSFlags;
+  if (!RISCVII::hasSEWOp(TSFlags))
+    return false;
+  assert(RISCVII::hasVLOp(TSFlags));
+  const unsigned Log2SEW = MI.getOperand(RISCVII::getSEWOpNum(MCID)).getImm();
+
+  if (UserOp.getOperandNo() == RISCVII::getVLOpNum(MCID))
+    return false;
+
+  // TODO: Handle Zvbb instructions
+  switch (PseudoInfo->BaseInstr) {
----------------
preames wrote:

Having a utility which took the base opcode, and returned the number of bits used by the scalar operand would seem to common a lot of the implementation here.  That could reasonable live in RISCVBaseInfo.h/cpp.  

https://github.com/llvm/llvm-project/pull/67419