From 57ec696dfdd45a82446b582ef22f9977bc5b2908 Mon Sep 17 00:00:00 2001
From: Hans Wennborg <hans@hanshq.net>
Date: Fri, 26 Jun 2015 16:48:02 +0000
Subject: [PATCH] Revert r240762 "[X86] Cleanup
 X86WindowsTargetObjectFile::getSectionForConstant"

It seems to have caused PR23966: "UNREACHABLE executed at ..\lib\Target\X86\X86TargetObjectFile.cpp:148"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240793 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86TargetObjectFile.cpp | 62 +++++++++++++++-----------
 1 file changed, 37 insertions(+), 25 deletions(-)

diff --git a/lib/Target/X86/X86TargetObjectFile.cpp b/lib/Target/X86/X86TargetObjectFile.cpp
index e026608fc85..f9f62904b64 100644
--- a/lib/Target/X86/X86TargetObjectFile.cpp
+++ b/lib/Target/X86/X86TargetObjectFile.cpp
@@ -131,40 +131,52 @@ static std::string APIntToHexString(const APInt &AI) {
   return HexString;
 }
 
+
 static std::string scalarConstantToHexString(const Constant *C) {
   Type *Ty = C->getType();
+  APInt AI;
   if (isa<UndefValue>(C)) {
-    return APIntToHexString(APInt::getNullValue(Ty->getPrimitiveSizeInBits()));
-  } else if (const auto *CFP = dyn_cast<ConstantFP>(C)) {
-    return APIntToHexString(CFP->getValueAPF().bitcastToAPInt());
-  } else if (const auto *CI = dyn_cast<ConstantInt>(C)) {
-    return APIntToHexString(CI->getValue());
-  } else if (const auto *VTy = dyn_cast<VectorType>(Ty)) {
-    std::string HexString;
-    for (int I = VTy->getNumElements() - 1, E = -1; I != E; --I)
-      HexString += scalarConstantToHexString(C->getAggregateElement(I));
-    return HexString;
+    AI = APInt(Ty->getPrimitiveSizeInBits(), /*val=*/0);
+  } else if (Ty->isFloatTy() || Ty->isDoubleTy()) {
+    const auto *CFP = cast<ConstantFP>(C);
+    AI = CFP->getValueAPF().bitcastToAPInt();
+  } else if (Ty->isIntegerTy()) {
+    const auto *CI = cast<ConstantInt>(C);
+    AI = CI->getValue();
+  } else {
+    llvm_unreachable("unexpected constant pool element type!");
   }
-  llvm_unreachable("unexpected constant pool element type!");
+  return APIntToHexString(AI);
 }
 
 MCSection *
 X86WindowsTargetObjectFile::getSectionForConstant(SectionKind Kind,
                                                   const Constant *C) const {
-  if (Kind.isMergeableConst() && C) {
-    const unsigned Characteristics = COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
-                                     COFF::IMAGE_SCN_MEM_READ |
-                                     COFF::IMAGE_SCN_LNK_COMDAT;
-    std::string COMDATSymName;
-    if (Kind.isMergeableConst4() || Kind.isMergeableConst8())
-      COMDATSymName = "__real@" + scalarConstantToHexString(C);
-    else if (Kind.isMergeableConst16())
-      COMDATSymName = "__xmm@" + scalarConstantToHexString(C);
-
-    if (!COMDATSymName.empty())
-      return getContext().getCOFFSection(".rdata", Characteristics, Kind,
-                                         COMDATSymName,
-                                         COFF::IMAGE_COMDAT_SELECT_ANY);
+  if (Kind.isReadOnly()) {
+    if (C) {
+      Type *Ty = C->getType();
+      SmallString<32> COMDATSymName;
+      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
+        COMDATSymName = "__real@";
+        COMDATSymName += scalarConstantToHexString(C);
+      } else if (const auto *VTy = dyn_cast<VectorType>(Ty)) {
+        uint64_t NumBits = VTy->getBitWidth();
+        if (NumBits == 128 || NumBits == 256) {
+          COMDATSymName = NumBits == 128 ? "__xmm@" : "__ymm@";
+          for (int I = VTy->getNumElements() - 1, E = -1; I != E; --I)
+            COMDATSymName +=
+                scalarConstantToHexString(C->getAggregateElement(I));
+        }
+      }
+      if (!COMDATSymName.empty()) {
+        unsigned Characteristics = COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
+                                   COFF::IMAGE_SCN_MEM_READ |
+                                   COFF::IMAGE_SCN_LNK_COMDAT;
+        return getContext().getCOFFSection(".rdata", Characteristics, Kind,
+                                           COMDATSymName,
+                                           COFF::IMAGE_COMDAT_SELECT_ANY);
+      }
+    }
   }
 
   return TargetLoweringObjectFile::getSectionForConstant(Kind, C);
-- 
2.34.1