[llvm] [llvm-c] Create a 128 bit floating point constant from 2 64 bit values (PR #164381)

[Nikita Popov via llvm-commits]

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@@ -1573,6 +1573,14 @@ LLVMValueRef LLVMConstRealOfStringAndSize(LLVMTypeRef RealTy, const char Str[],
   return wrap(ConstantFP::get(unwrap(RealTy), StringRef(Str, SLen)));
 }
 
+LLVMValueRef LLVMConstFP128(LLVMTypeRef Ty, const uint64_t N[2]) {
+  Type *T = unwrap(Ty);
+  assert(T->getPrimitiveSizeInBits() == 128 && "Ty size should be 128");
+  APInt AI(128, ArrayRef<uint64_t>(N, 2));
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nikic wrote:

Rather than hardcoding 128 here, we can use the size of the float (e.g. via getScalarSizeInBits). The corresponding size of the array would be `divideCeil(SizeInBits, 64)`. Then this would work for all sizes of floats.

https://github.com/llvm/llvm-project/pull/164381