[llvm] [Mips] Do not emit instruction teq if divisor is non-zero immediate value in FastISel implementation (PR #135768)

[YunQiang Su via llvm-commits]

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@@ -1947,7 +1947,12 @@ bool MipsFastISel::selectDivRem(const Instruction *I, unsigned ISDOpcode) {
     return false;
 
   emitInst(DivOpc).addReg(Src0Reg).addReg(Src1Reg);
-  emitInst(Mips::TEQ).addReg(Src1Reg).addReg(Mips::ZERO).addImm(7);
+  if (const ConstantInt *C = dyn_cast<ConstantInt>(I->getOperand(1))) {
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wzssyqa wrote:

Soooo cooool.
While we can have a better code style.
Something like
```
if (!isa<ConstantInt>(I->getOperand(1)) || I->getConstantOperandVal(1) == 0)
   ...
else
  ...
```

https://github.com/llvm/llvm-project/pull/135768