[llvm] [NVPTX] Propagate truncate to operands (PR #98666)

[Matt Arsenault via llvm-commits]

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@@ -2975,6 +2975,8 @@ class TargetLoweringBase {
     return isTruncateFree(Val.getValueType(), VT2);
   }
 
+  virtual bool shouldReduceRegisterPressure() const { return false; }
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arsenm wrote:

Please do not add any vague, argument-free, undocumented target lowering hooks. We have far too many single purpose random hooks like this. If it has no arguments, it probably should not be a virtual. 

Every target would claim yes, this needs to be more specific why. From the context, this is probably already covered by existing APIs (probably isTruncateFree)? 

https://github.com/llvm/llvm-project/pull/98666