[llvm] [AArch64] Change f128 costs to 10 * legalization factor. (PR #202555)

[David Green via llvm-commits]

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@@ -4389,6 +4389,11 @@ InstructionCost AArch64TTIImpl::getArithmeticInstrCost(
             }))
       return *PromotedCost;
 
+    // fp128 all go via libcalls
+    if (Ty->getScalarType()->isFP128Ty())
+      return CostKind == TTI::TCK_CodeSize ? 1 : 10 * LT.first;
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davemgreen wrote:

Good point, I have added some brackets. Unfortunately we don't really get here with CodeSize costs at the moment. I am hoping to work towards #154381, making that patch smaller by pulling parts of it out but might get stuck on regressions again.

https://github.com/llvm/llvm-project/pull/202555