[PATCH] D69116: [TargetLowering][DAGCombine][MSP430] Shift Amount Threshold in DAGCombine (1/2)

[Joan LLuch via Phabricator via llvm-commits]

joanlluch added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:3622
+          if (AndRHS->getAPIntValue().isPowerOf2() &&
+                ShCt <= TLI.getShiftAmountThreshold(ShiftTy)) {
             return DAG.getNode(ISD::TRUNCATE, dl, VT,
----------------
joanlluch wrote:
> spatel wrote:
> > This is probably not working as you expected because the shift type may not be the same as the value type.
> > I added an x86 test to demonstrate:
> > rL375158
> Would passing the shift value  (not the constant amount type) to getShiftAmountThreshold work in all cases?
I mean passing the shift value //type//, not the shift value, of course., so in the case above would be TLI.getShiftAmountThreshold(N0.getValueType()) 
Would that look good?


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  https://reviews.llvm.org/D69116/new/

https://reviews.llvm.org/D69116