[ConstantFolding] Ensure TLI is valid when simplifying fp128 intrinsics.

TLI might not be valid for all contexts that constant folding is performed. Add
a quick guard that it is not null.

Author: davemgreen

llvm/lib/Analysis/ConstantFolding.cpp

@@ -2140,7 +2140,7 @@ static Constant *ConstantFoldScalarCall1(StringRef Name,
         return GetConstantFoldFPValue128(Result, Ty);
       }
       LibFunc Fp128Func = NotLibFunc;
-      if (TLI->getLibFunc(Name, Fp128Func) && TLI->has(Fp128Func) &&
+      if (TLI && TLI->getLibFunc(Name, Fp128Func) && TLI->has(Fp128Func) &&
           Fp128Func == LibFunc_logl)
         return ConstantFoldFP128(logf128, Op->getValueAPF(), Ty);
     }

llvm/test/Transforms/Inline/simplify-fp128.ll

@@ -0,0 +1,24 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=inline -S | FileCheck %s
+
+define void @fli() {
+; CHECK-LABEL: define void @fli() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = call fp128 @llvm.floor.f128(fp128 0xL999999999999999A4001199999999999)
+; CHECK-NEXT:    ret void
+;
+entry:
+  call void @sc()
+  ret void
+}
+
+define void @sc() {
+; CHECK-LABEL: define void @sc() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = tail call fp128 @llvm.floor.f128(fp128 0xL999999999999999A4001199999999999)
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = tail call fp128 @llvm.floor.f128(fp128 0xL999999999999999A4001199999999999)
+  ret void
+}