[llvm] [LoopIdiom] Don't convert `memset.inline` into `memset` (PR #227650)

[Ömer Sinan Ağacan via llvm-commits]

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@@ -837,8 +837,10 @@ bool LoopIdiomRecognize::processLoopMemCpy(MemCpyInst *MCI,
   if (MCI->isVolatile() || !isa<ConstantInt>(MCI->getLength()))
     return false;
 
-  // If we're not allowed to hack on memcpy, we fail.
-  if ((!HasMemcpy && !MCI->isForceInlined()) || DisableLIRP::Memcpy)
+  // If we're not allowed to hack on memcpy, we fail. We don't mess with the
+  // inlined version as generating a larger inline mempcy could affect code
+  // size.
+  if (!HasMemcpy || MCI->isForceInlined() || DisableLIRP::Memcpy)
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osa1 wrote:

Test already exists: llvm/test/Transforms/LoopIdiom/memcpy-inline-intrinsic.ll
Updated the commit message.

https://github.com/llvm/llvm-project/pull/227650