From 7f4b6696c14ed451ee9342c2adb852b8ee7ed6a5 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Tue, 15 Jul 2014 02:34:12 +0000
Subject: [PATCH] CodeGen: Handle ConstantVector and undef in WinCOFF constant
 pools

The constant pool entry code for WinCOFF assumed that vector constants
would be formed using ConstantDataVector, it did not expect to see a
ConstantVector.  Furthermore, it did not expect undef as one of the
elements of the vector.

ConstantVectors should be handled like ConstantDataVectors, treat Undef
as zero.

llvm-svn: 213038
---
 lib/Target/X86/X86TargetObjectFile.cpp | 34 ++++++++++++++++----------
 test/CodeGen/X86/win_cst_pool.ll       | 17 +++++++++++++
 2 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/lib/Target/X86/X86TargetObjectFile.cpp b/lib/Target/X86/X86TargetObjectFile.cpp
index c7802320b06..21ee047594b 100644
--- a/lib/Target/X86/X86TargetObjectFile.cpp
+++ b/lib/Target/X86/X86TargetObjectFile.cpp
@@ -109,7 +109,8 @@ const MCExpr *X86WindowsTargetObjectFile::getExecutableRelativeSymbol(
                                  getContext());
 }
 
-static std::string APIntToHexString(const APInt &AI, unsigned Width) {
+static std::string APIntToHexString(const APInt &AI) {
+  unsigned Width = (AI.getBitWidth() / 8) * 2;
   std::string HexString = utohexstr(AI.getLimitedValue(), /*LowerCase=*/true);
   unsigned Size = HexString.size();
   assert(Width >= Size && "hex string is too large!");
@@ -121,17 +122,19 @@ static std::string APIntToHexString(const APInt &AI, unsigned Width) {
 
 static std::string scalarConstantToHexString(const Constant *C) {
   Type *Ty = C->getType();
-  if (Ty->isFloatTy()) {
+  APInt AI;
+  if (isa<UndefValue>(C)) {
+    AI = APInt(Ty->getPrimitiveSizeInBits(), /*val=*/0);
+  } else if (Ty->isFloatTy() || Ty->isDoubleTy()) {
     const auto *CFP = cast<ConstantFP>(C);
-    return APIntToHexString(CFP->getValueAPF().bitcastToAPInt(), /*Width=*/8);
-  } else if (Ty->isDoubleTy()) {
-    const auto *CFP = cast<ConstantFP>(C);
-    return APIntToHexString(CFP->getValueAPF().bitcastToAPInt(), /*Width=*/16);
-  } else if (const auto *ITy = dyn_cast<IntegerType>(Ty)) {
+    AI = CFP->getValueAPF().bitcastToAPInt();
+  } else if (Ty->isIntegerTy()) {
     const auto *CI = cast<ConstantInt>(C);
-    return APIntToHexString(CI->getValue(), (ITy->getBitWidth() / 8) * 2);
+    AI = CI->getValue();
+  } else {
+    llvm_unreachable("unexpected constant pool element type!");
   }
-  llvm_unreachable("unexpected constant pool element type!");
+  return APIntToHexString(AI);
 }
 
 const MCSection *
@@ -147,11 +150,16 @@ X86WindowsTargetObjectFile::getSectionForConstant(SectionKind Kind,
       } else if (const auto *VTy = dyn_cast<VectorType>(Ty)) {
         uint64_t NumBits = VTy->getBitWidth();
         if (NumBits == 128 || NumBits == 256) {
-          const auto *CDV = cast<ConstantDataVector>(C);
           COMDATSymName = NumBits == 128 ? "__xmm@" : "__ymm@";
-          for (int I = CDV->getNumElements() - 1, E = -1; I != E; --I)
-            COMDATSymName +=
-                scalarConstantToHexString(CDV->getElementAsConstant(I));
+          if (const auto *CDV = dyn_cast<ConstantDataVector>(C)) {
+            for (int I = CDV->getNumElements() - 1, E = -1; I != E; --I)
+              COMDATSymName +=
+                  scalarConstantToHexString(CDV->getElementAsConstant(I));
+          } else {
+            const auto *CV = cast<ConstantVector>(C);
+            for (int I = CV->getNumOperands() - 1, E = -1; I != E; --I)
+              COMDATSymName += scalarConstantToHexString(CV->getOperand(I));
+          }
         }
       }
       if (!COMDATSymName.empty()) {
diff --git a/test/CodeGen/X86/win_cst_pool.ll b/test/CodeGen/X86/win_cst_pool.ll
index 7bc046d94e9..e8b853a03da 100644
--- a/test/CodeGen/X86/win_cst_pool.ll
+++ b/test/CodeGen/X86/win_cst_pool.ll
@@ -47,3 +47,20 @@ define <8 x i16> @vec2() {
 ; CHECK:      vec2:
 ; CHECK:               movaps  __xmm@00000001000200030004000500060007(%rip), %xmm0
 ; CHECK-NEXT:          ret
+
+
+define <4 x float> @undef1() {
+  ret <4 x float> <float 1.0, float 1.0, float undef, float undef>
+
+; CHECK:             .globl  __xmm@00000000000000003f8000003f800000
+; CHECK-NEXT:        .section        .rdata,"rd",discard,__xmm@00000000000000003f8000003f800000
+; CHECK-NEXT:        .align  16
+; CHECK-NEXT: __xmm@00000000000000003f8000003f800000:
+; CHECK-NEXT:        .long   1065353216              # float 1
+; CHECK-NEXT:        .long   1065353216              # float 1
+; CHECK-NEXT:        .zero   4
+; CHECK-NEXT:        .zero   4
+; CHECK:      undef1:
+; CHECK:               movaps  __xmm@00000000000000003f8000003f800000(%rip), %xmm0
+; CHECK-NEXT:          ret
+}