[PATCH] D63212: [ARM] Scan for existing loop intrinsics

[Sam Parker via Phabricator via llvm-commits]

samparker marked an inline comment as done.
samparker added inline comments.


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Comment at: lib/Target/ARM/ARMTargetTransformInfo.cpp:839
   HWLoopInfo.CounterInReg = true;
+  HWLoopInfo.IsNestingLegal = false;
   HWLoopInfo.CountType = Type::getInt32Ty(C);
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SjoerdMeijer wrote:
> We can nest hwloops, so it would be legal, but we think it will never be benecial because it involves spilling and reloading LR. Do we really need to set IsNestingLegal? Don't think this is important, but was just curious; I haven't looked and reminded myself how it is used.
Yep, so 'Legal' is a bit of a misnomer, but it prevents the independent pass from trying to generate nested hardware loops. The default is false, but I wanted to make it explicit here too.


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https://reviews.llvm.org/D63212