[PATCH] D130862: [LegalizeTypes] Improve splitting for urem/udiv by constant for some constants.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:7237-7242
+      if (getBooleanContents(HiLoVT) ==
+          TargetLoweringBase::ZeroOrOneBooleanContent)
+        Carry = DAG.getZExtOrTrunc(Carry, dl, HiLoVT);
+      else
+        Carry = DAG.getSelect(dl, HiLoVT, Carry, DAG.getConstant(1, dl, HiLoVT),
+                              DAG.getConstant(0, dl, HiLoVT));
----------------
arsenm wrote:
> Can't you just unconditionally use getZExtOrTrunc? the booleancontents would just apply the optimization fold later
I wrote it like this because that's what was done for ISD::SUB at the end of ExpandIntRes_ADDSUB. ISD::ADD in that function seemed more complicated that it needs to be.


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  https://reviews.llvm.org/D130862/new/

https://reviews.llvm.org/D130862