[AutoUpgrade] Fix AutoUpgrade for x86.seh.recoverfp

[mgrang]

Summary

This fixes the bug in https://reviews.llvm.org/D56747#inline-502711.

[mgrang]

Added unit test.

[efriedma]

LGTM

lib/IR/AutoUpgrade.cpp

if (Idx->isFPOrFPVectorTy()) {
         Permil2ID = Intrinsic::x86_xop_vpermil2pd_256;
       else
         Permil2ID = Intrinsic::x86_xop_vpermil2ps_256;
       NewFn = Intrinsic::getDeclaration(F->getParent(), Permil2ID);
       return true;
     }
   }
 
+  if (Name == "seh.recoverfp") {
+    NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_recoverfp);
+    return true;
+  }
+
   return false;
 }
 
 static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
   assert(F && "Illegal to upgrade a non-existent Function.");
 
   // Quickly eliminate it, if it's not a candidate.
   StringRef Name = F->getName();
if (vstRegex.match(Name)) {
         NewFn = Intrinsic::getDeclaration(F->getParent(),
                                           StoreLaneInts[fArgs.size() - 5], Tys);
       return true;
     }
     if (Name == "aarch64.thread.pointer" || Name == "arm.thread.pointer") {
       NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::thread_pointer);
       return true;
     }
-    if (Name == "x86.seh.recoverfp") {
-      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_recoverfp);
-      return true;
-    }
     break;
   }
 
   case 'c': {
     if (Name.startswith("ctlz.") && F->arg_size() == 1) {
       rename(F);
       NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
                                         F->arg_begin()->getType());

test/CodeGen/AArch64/eh_recoverfp.ll

+; RUN: llc -mtriple arm64-windows %s -o - 2>&1 | FileCheck %s
+
+define i8* @foo(i8* %a) {
+; CHECK-LABEL: foo
+; CHECK-NOT: llvm.x86.seh.recoverfp
+  %1 = call i8* @llvm.x86.seh.recoverfp(i8* bitcast (i32 ()* @f to i8*), i8* %a)
+  ret i8* %1
+}
+
+declare i8* @llvm.x86.seh.recoverfp(i8*, i8*)
+declare i32 @f()