Add support for bitcasts to vector type in Evaluate.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147137 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 115 insertions, 5 deletions

diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index e9b9d14daf..2805978179 100644
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -64,6 +64,7 @@ class TargetInfo : public llvm::RefCountedBase<TargetInfo> {
 protected:
   // Target values set by the ctor of the actual target implementation.  Default
   // values are specified by the TargetInfo constructor.
+  bool BigEndian;
   bool TLSSupported;
   bool NoAsmVariants;  // True if {|} are normal characters.
   unsigned char PointerWidth, PointerAlign;
@@ -621,6 +622,8 @@ public:
   /// which the program should be compiled.
   VersionTuple getPlatformMinVersion() const { return PlatformMinVersion; }
 
+  bool isBigEndian() const { return BigEndian; }
+
 protected:
   virtual uint64_t getPointerWidthV(unsigned AddrSpace) const {
     return PointerWidth;
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index c58a568876..96a1785e14 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -913,6 +913,53 @@ static bool HandleIntToFloatCast(EvalInfo &Info, const Expr *E,
   return true;
 }
 
+static bool EvalAndBitcastToAPInt(EvalInfo &Info, const Expr *E,
+                                  llvm::APInt &Res) {
+  CCValue SVal;
+  if (!Evaluate(SVal, Info, E))
+    return false;
+  if (SVal.isInt()) {
+    Res = SVal.getInt();
+    return true;
+  }
+  if (SVal.isFloat()) {
+    Res = SVal.getFloat().bitcastToAPInt();
+    return true;
+  }
+  if (SVal.isVector()) {
+    QualType VecTy = E->getType();
+    unsigned VecSize = Info.Ctx.getTypeSize(VecTy);
+    QualType EltTy = VecTy->castAs<VectorType>()->getElementType();
+    unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
+    bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
+    Res = llvm::APInt::getNullValue(VecSize);
+    for (unsigned i = 0; i < SVal.getVectorLength(); i++) {
+      APValue &Elt = SVal.getVectorElt(i);
+      llvm::APInt EltAsInt;
+      if (Elt.isInt()) {
+        EltAsInt = Elt.getInt();
+      } else if (Elt.isFloat()) {
+        EltAsInt = Elt.getFloat().bitcastToAPInt();
+      } else {
+        // Don't try to handle vectors of anything other than int or float
+        // (not sure if it's possible to hit this case).
+        Info.Diag(E->getExprLoc(), diag::note_invalid_subexpr_in_const_expr);
+        return false;
+      }
+      unsigned BaseEltSize = EltAsInt.getBitWidth();
+      if (BigEndian)
+        Res |= EltAsInt.zextOrTrunc(VecSize).rotr(i*EltSize+BaseEltSize);
+      else
+        Res |= EltAsInt.zextOrTrunc(VecSize).rotl(i*EltSize);
+    }
+    return true;
+  }
+  // Give up if the input isn't an int, float, or vector.  For example, we
+  // reject "(v4i16)(intptr_t)&a".
+  Info.Diag(E->getExprLoc(), diag::note_invalid_subexpr_in_const_expr);
+  return false;
+}
+
 static bool FindMostDerivedObject(EvalInfo &Info, const LValue &LVal,
                                   const CXXRecordDecl *&MostDerivedType,
                                   unsigned &MostDerivedPathLength,
@@ -2977,6 +3024,44 @@ bool VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
     SmallVector<APValue, 4> Elts(NElts, Val);
     return Success(Elts, E);
   }
+  case CK_BitCast: {
+    // Evaluate the operand into an APInt we can extract from.
+    llvm::APInt SValInt;
+    if (!EvalAndBitcastToAPInt(Info, SE, SValInt))
+      return false;
+    // Extract the elements
+    QualType EltTy = VTy->getElementType();
+    unsigned EltSize = Info.Ctx.getTypeSize(EltTy);
+    bool BigEndian = Info.Ctx.getTargetInfo().isBigEndian();
+    SmallVector<APValue, 4> Elts;
+    if (EltTy->isRealFloatingType()) {
+      const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(EltTy);
+      bool isIEESem = &Sem != &APFloat::PPCDoubleDouble;
+      unsigned FloatEltSize = EltSize;
+      if (&Sem == &APFloat::x87DoubleExtended)
+        FloatEltSize = 80;
+      for (unsigned i = 0; i < NElts; i++) {
+        llvm::APInt Elt;
+        if (BigEndian)
+          Elt = SValInt.rotl(i*EltSize+FloatEltSize).trunc(FloatEltSize);
+        else
+          Elt = SValInt.rotr(i*EltSize).trunc(FloatEltSize);
+        Elts.push_back(APValue(APFloat(Elt, isIEESem)));
+      }
+    } else if (EltTy->isIntegerType()) {
+      for (unsigned i = 0; i < NElts; i++) {
+        llvm::APInt Elt;
+        if (BigEndian)
+          Elt = SValInt.rotl(i*EltSize+EltSize).zextOrTrunc(EltSize);
+        else
+          Elt = SValInt.rotr(i*EltSize).zextOrTrunc(EltSize);
+        Elts.push_back(APValue(APSInt(Elt, EltTy->isSignedIntegerType())));
+      }
+    } else {
+      return Error(E);
+    }
+    return Success(Elts, E);
+  }
   default:
     return ExprEvaluatorBaseTy::VisitCastExpr(E);
   }
diff --git a/lib/Basic/TargetInfo.cpp b/lib/Basic/TargetInfo.cpp
index 66274f11fc..f938b5a604 100644
--- a/lib/Basic/TargetInfo.cpp
+++ b/lib/Basic/TargetInfo.cpp
@@ -27,6 +27,7 @@ static const LangAS::Map DefaultAddrSpaceMap = { 0 };
 TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
   // Set defaults.  Defaults are set for a 32-bit RISC platform, like PPC or
   // SPARC.  These should be overridden by concrete targets as needed.
+  BigEndian = true;
   TLSSupported = true;
   NoAsmVariants = false;
   PointerWidth = PointerAlign = 32;
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index b9f505c86b..d61d3cd7cf 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -910,6 +910,7 @@ namespace {
     std::vector<llvm::StringRef> AvailableFeatures;
   public:
     PTXTargetInfo(const std::string& triple) : TargetInfo(triple) {
+      BigEndian = false;
       TLSSupported = false;
       LongWidth = LongAlign = 64;
       AddrSpaceMap = &PTXAddrSpaceMap;
@@ -1331,6 +1332,7 @@ public:
   X86TargetInfo(const std::string& triple)
     : TargetInfo(triple), SSELevel(NoSSE), MMX3DNowLevel(NoMMX3DNow),
       HasAES(false), HasAVX(false), HasAVX2(false), CPU(CK_Generic) {
+    BigEndian = false;
     LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;
   }
   virtual void getTargetBuiltins(const Builtin::Info *&Records,
@@ -2482,6 +2484,7 @@ public:
   ARMTargetInfo(const std::string &TripleStr)
     : TargetInfo(TripleStr), ABI("aapcs-linux"), CPU("arm1136j-s")
   {
+    BigEndian = false;
     SizeType = UnsignedInt;
     PtrDiffType = SignedInt;
     // AAPCS 7.1.1, ARM-Linux ABI 2.4: type of wchar_t is unsigned int.
@@ -2847,6 +2850,7 @@ class HexagonTargetInfo : public TargetInfo {
   std::string CPU;
 public:
   HexagonTargetInfo(const std::string& triple) : TargetInfo(triple)  {
+    BigEndian = false;
     DescriptionString = ("e-p:32:32:32-"
                          "i64:64:64-i32:32:32-"
                          "i16:16:16-i1:32:32-a:0:0");
@@ -2976,6 +2980,7 @@ class SparcV8TargetInfo : public TargetInfo {
 public:
   SparcV8TargetInfo(const std::string& triple) : TargetInfo(triple) {
     // FIXME: Support Sparc quad-precision long double?
+    BigEndian = false;
     DescriptionString = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
                         "i64:64:64-f32:32:32-f64:64:64-v64:64:64-n32";
   }
@@ -3105,6 +3110,7 @@ namespace {
     static const char * const GCCRegNames[];
   public:
     MSP430TargetInfo(const std::string& triple) : TargetInfo(triple) {
+      BigEndian = false;
       TLSSupported = false;
       IntWidth = 16; IntAlign = 16;
       LongWidth = 32; LongLongWidth = 64;
@@ -3399,6 +3405,7 @@ public:
 class Mips32ELTargetInfo : public Mips32TargetInfoBase {
 public:
   Mips32ELTargetInfo(const std::string& triple) : Mips32TargetInfoBase(triple) {
+    BigEndian = false;
     DescriptionString = "e-p:32:32:32-i1:8:8-i8:8:32-i16:16:32-i32:32:32-"
                         "i64:64:64-f32:32:32-f64:64:64-v64:64:64-n32";
   }
@@ -3530,7 +3537,8 @@ class Mips64ELTargetInfo : public Mips64TargetInfoBase {
   }
 public:
   Mips64ELTargetInfo(const std::string& triple) : Mips64TargetInfoBase(triple) {
-    // Default ABI is n64.  
+    // Default ABI is n64.
+    BigEndian = false;
     DescriptionString = "e-p:64:64:64-i1:8:8-i8:8:32-i16:16:32-i32:32:32-"
                         "i64:64:64-f32:32:32-f64:64:64-f128:128:128-"
                         "v64:64:64-n32";
@@ -3551,6 +3559,7 @@ namespace {
 class PNaClTargetInfo : public TargetInfo {
 public:
   PNaClTargetInfo(const std::string& triple) : TargetInfo(triple) {
+    BigEndian = false;
     this->UserLabelPrefix = "";
     this->LongAlign = 32;
     this->LongWidth = 32;
diff --git a/test/CodeGen/altivec.c b/test/CodeGen/altivec.c
index bd694a6a56..29823031b5 100644
--- a/test/CodeGen/altivec.c
+++ b/test/CodeGen/altivec.c
@@ -5,13 +5,13 @@
 vector int test0 = (vector int)(1);       // CHECK: @test0 = global <4 x i32> <i32 1, i32 1, i32 1, i32 1>
 vector float test1 = (vector float)(1.0); // CHECK: @test1 = global <4 x float> <float 1.000000e+{{0+}}, float 1.000000e+{{0+}}, float 1.000000e+{{0+}}, float 1.000000e+{{0+}}>
 
-// CHECK: @v1 = global <16 x i8> bitcast (<4 x i32> <i32 1, i32 2, i32 3, i32 4> to <16 x i8>)
+// CHECK: @v1 = global <16 x i8> <i8 0, i8 0, i8 0, i8 1, i8 0, i8 0, i8 0, i8 2, i8 0, i8 0, i8 0, i8 3, i8 0, i8 0, i8 0, i8 4>
 vector char v1 = (vector char)((vector int)(1, 2, 3, 4));
-// CHECK: @v2 = global <16 x i8> bitcast (<4 x float> <float 1.000000e+{{0+}}, float 2.000000e+{{0+}}, float 3.000000e+{{0+}}, float 4.000000e+{{0+}}> to <16 x i8>)
+// CHECK: @v2 = global <16 x i8> <i8 63, i8 -128, i8 0, i8 0, i8 64, i8 0, i8 0, i8 0, i8 64, i8 64, i8 0, i8 0, i8 64, i8 -128, i8 0, i8 0>
 vector char v2 = (vector char)((vector float)(1.0f, 2.0f, 3.0f, 4.0f));
-// CHECK: @v3 = global <16 x i8> bitcast (<4 x i32> <i32 97, i32 98, i32 99, i32 100> to <16 x i8>)
+// CHECK: @v3 = global <16 x i8> <i8 0, i8 0, i8 0, i8 97, i8 0, i8 0, i8 0, i8 98, i8 0, i8 0, i8 0, i8 99, i8 0, i8 0, i8 0, i8 100>
 vector char v3 = (vector char)((vector int)('a', 'b', 'c', 'd'));
-// CHECK: @v4 = global <4 x i32> bitcast (<16 x i8> <i8 1, i8 2, i8 3, i8 4, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0> to <4 x i32>)
+// CHECK: @v4 = global <4 x i32> <i32 16909060, i32 0, i32 0, i32 0>
 vector int v4 = (vector char){1, 2, 3, 4};
 
 void test2()
diff --git a/test/CodeGen/const-init.c b/test/CodeGen/const-init.c
index 9bc3bbafde..4f3f7ab553 100644
--- a/test/CodeGen/const-init.c
+++ b/test/CodeGen/const-init.c
@@ -132,3 +132,15 @@ int g25() {
 void g27() { // PR8073
   static void *x = &x;
 }
+
+void g28() {
+  typedef long long v1i64 __attribute((vector_size(8)));
+  typedef short v12i16 __attribute((vector_size(24)));
+  typedef long double v2f80 __attribute((vector_size(24)));
+  // CHECK: @g28.a = internal global <1 x i64> <i64 10>
+  // CHECK: @g28.b = internal global <12 x i16> <i16 0, i16 0, i16 0, i16 -32768, i16 16383, i16 0, i16 0, i16 0, i16 0, i16 -32768, i16 16384, i16 0>
+  // CHECK: @g28.c = internal global <2 x x86_fp80> <x86_fp80 0xK3FFF8000000000000000, x86_fp80 0xK40008000000000000000>, align 32
+  static v1i64 a = (v1i64)10LL;
+  static v12i16 b = (v2f80){1,2};
+  static v2f80 c = (v12i16){0,0,0,-32768,16383,0,0,0,0,-32768,16384,0};
+}