[llvm] [BPF] Support signed division at cpu v1 with constant divisor (PR #110627)

[via llvm-commits]

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@@ -565,7 +565,12 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
       if (!isa<ConstantInt>(Inst.getOperand(1)))
         return false;
       EVT VT = getTLI()->getValueType(DL, Inst.getType());
-      return !getTLI()->isIntDivCheap(VT, Fn.getAttributes());
+
+      bool IsSigned = true;
+      if (Inst.getOpcode() == Instruction::SDiv ||
+          Inst.getOpcode() == Instruction::SRem)
+        IsSigned = false;
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4ast wrote:

I don't think we need to differentiate signed vs unsigned here.
Both kinds of division are expensive. This transformation is necessary in all cases.
That should avoid adding isSigned everywhere.

https://github.com/llvm/llvm-project/pull/110627