vendor/llvm/llvm-trunk-r351319

1 files changed, 258 insertions, 59 deletions

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index c5281c57bc19..5da29d6d2372 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -347,9 +347,20 @@ Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy,
 
     // We're simulating a load through a pointer that was bitcast to point to
     // a different type, so we can try to walk down through the initial
-    // elements of an aggregate to see if some part of th e aggregate is
+    // elements of an aggregate to see if some part of the aggregate is
     // castable to implement the "load" semantic model.
-    C = C->getAggregateElement(0u);
+    if (SrcTy->isStructTy()) {
+      // Struct types might have leading zero-length elements like [0 x i32],
+      // which are certainly not what we are looking for, so skip them.
+      unsigned Elem = 0;
+      Constant *ElemC;
+      do {
+        ElemC = C->getAggregateElement(Elem++);
+      } while (ElemC && DL.getTypeSizeInBits(ElemC->getType()) == 0);
+      C = ElemC;
+    } else {
+      C = C->getAggregateElement(0u);
+    }
   } while (C);
 
   return nullptr;
@@ -960,10 +971,8 @@ Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
         NewIdxs.size() > *LastIRIndex) {
       InRangeIndex = LastIRIndex;
       for (unsigned I = 0; I <= *LastIRIndex; ++I)
-        if (NewIdxs[I] != InnermostGEP->getOperand(I + 1)) {
-          InRangeIndex = None;
-          break;
-        }
+        if (NewIdxs[I] != InnermostGEP->getOperand(I + 1))
+          return nullptr;
     }
 
   // Create a GEP.
@@ -985,11 +994,6 @@ Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
 /// returned, if not, null is returned.  Note that this function can fail when
 /// attempting to fold instructions like loads and stores, which have no
 /// constant expression form.
-///
-/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/inrange
-/// etc information, due to only being passed an opcode and operands. Constant
-/// folding using this function strips this information.
-///
 Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, unsigned Opcode,
                                        ArrayRef<Constant *> Ops,
                                        const DataLayout &DL,
@@ -1370,6 +1374,8 @@ bool llvm::canConstantFoldCallTo(ImmutableCallSite CS, const Function *F) {
   case Intrinsic::fabs:
   case Intrinsic::minnum:
   case Intrinsic::maxnum:
+  case Intrinsic::minimum:
+  case Intrinsic::maximum:
   case Intrinsic::log:
   case Intrinsic::log2:
   case Intrinsic::log10:
@@ -1389,6 +1395,8 @@ bool llvm::canConstantFoldCallTo(ImmutableCallSite CS, const Function *F) {
   case Intrinsic::ctpop:
   case Intrinsic::ctlz:
   case Intrinsic::cttz:
+  case Intrinsic::fshl:
+  case Intrinsic::fshr:
   case Intrinsic::fma:
   case Intrinsic::fmuladd:
   case Intrinsic::copysign:
@@ -1402,6 +1410,10 @@ bool llvm::canConstantFoldCallTo(ImmutableCallSite CS, const Function *F) {
   case Intrinsic::usub_with_overflow:
   case Intrinsic::smul_with_overflow:
   case Intrinsic::umul_with_overflow:
+  case Intrinsic::sadd_sat:
+  case Intrinsic::uadd_sat:
+  case Intrinsic::ssub_sat:
+  case Intrinsic::usub_sat:
   case Intrinsic::convert_from_fp16:
   case Intrinsic::convert_to_fp16:
   case Intrinsic::bitreverse:
@@ -1413,6 +1425,23 @@ bool llvm::canConstantFoldCallTo(ImmutableCallSite CS, const Function *F) {
   case Intrinsic::x86_sse2_cvtsd2si64:
   case Intrinsic::x86_sse2_cvttsd2si:
   case Intrinsic::x86_sse2_cvttsd2si64:
+  case Intrinsic::x86_avx512_vcvtss2si32:
+  case Intrinsic::x86_avx512_vcvtss2si64:
+  case Intrinsic::x86_avx512_cvttss2si:
+  case Intrinsic::x86_avx512_cvttss2si64:
+  case Intrinsic::x86_avx512_vcvtsd2si32:
+  case Intrinsic::x86_avx512_vcvtsd2si64:
+  case Intrinsic::x86_avx512_cvttsd2si:
+  case Intrinsic::x86_avx512_cvttsd2si64:
+  case Intrinsic::x86_avx512_vcvtss2usi32:
+  case Intrinsic::x86_avx512_vcvtss2usi64:
+  case Intrinsic::x86_avx512_cvttss2usi:
+  case Intrinsic::x86_avx512_cvttss2usi64:
+  case Intrinsic::x86_avx512_vcvtsd2usi32:
+  case Intrinsic::x86_avx512_vcvtsd2usi64:
+  case Intrinsic::x86_avx512_cvttsd2usi:
+  case Intrinsic::x86_avx512_cvttsd2usi64:
+  case Intrinsic::is_constant:
     return true;
   default:
     return false;
@@ -1553,7 +1582,7 @@ Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), double V,
 /// result. Returns null if the conversion cannot be performed, otherwise
 /// returns the Constant value resulting from the conversion.
 Constant *ConstantFoldSSEConvertToInt(const APFloat &Val, bool roundTowardZero,
-                                      Type *Ty) {
+                                      Type *Ty, bool IsSigned) {
   // All of these conversion intrinsics form an integer of at most 64bits.
   unsigned ResultWidth = Ty->getIntegerBitWidth();
   assert(ResultWidth <= 64 &&
@@ -1565,11 +1594,11 @@ Constant *ConstantFoldSSEConvertToInt(const APFloat &Val, bool roundTowardZero,
                                               : APFloat::rmNearestTiesToEven;
   APFloat::opStatus status =
       Val.convertToInteger(makeMutableArrayRef(UIntVal), ResultWidth,
-                           /*isSigned=*/true, mode, &isExact);
+                           IsSigned, mode, &isExact);
   if (status != APFloat::opOK &&
       (!roundTowardZero || status != APFloat::opInexact))
     return nullptr;
-  return ConstantInt::get(Ty, UIntVal, /*isSigned=*/true);
+  return ConstantInt::get(Ty, UIntVal, IsSigned);
 }
 
 double getValueAsDouble(ConstantFP *Op) {
@@ -1587,14 +1616,49 @@ double getValueAsDouble(ConstantFP *Op) {
   return APF.convertToDouble();
 }
 
+static bool isManifestConstant(const Constant *c) {
+  if (isa<ConstantData>(c)) {
+    return true;
+  } else if (isa<ConstantAggregate>(c) || isa<ConstantExpr>(c)) {
+    for (const Value *subc : c->operand_values()) {
+      if (!isManifestConstant(cast<Constant>(subc)))
+        return false;
+    }
+    return true;
+  }
+  return false;
+}
+
+static bool getConstIntOrUndef(Value *Op, const APInt *&C) {
+  if (auto *CI = dyn_cast<ConstantInt>(Op)) {
+    C = &CI->getValue();
+    return true;
+  }
+  if (isa<UndefValue>(Op)) {
+    C = nullptr;
+    return true;
+  }
+  return false;
+}
+
 Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
                                  ArrayRef<Constant *> Operands,
                                  const TargetLibraryInfo *TLI,
                                  ImmutableCallSite CS) {
   if (Operands.size() == 1) {
+    if (IntrinsicID == Intrinsic::is_constant) {
+      // We know we have a "Constant" argument. But we want to only
+      // return true for manifest constants, not those that depend on
+      // constants with unknowable values, e.g. GlobalValue or BlockAddress.
+      if (isManifestConstant(Operands[0]))
+        return ConstantInt::getTrue(Ty->getContext());
+      return nullptr;
+    }
     if (isa<UndefValue>(Operands[0])) {
-      // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN
-      if (IntrinsicID == Intrinsic::cos)
+      // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN.
+      // ctpop() is between 0 and bitwidth, pick 0 for undef.
+      if (IntrinsicID == Intrinsic::cos ||
+          IntrinsicID == Intrinsic::ctpop)
         return Constant::getNullValue(Ty);
       if (IntrinsicID == Intrinsic::bswap ||
           IntrinsicID == Intrinsic::bitreverse ||
@@ -1849,7 +1913,8 @@ Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
         if (ConstantFP *FPOp =
                 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
           return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
-                                             /*roundTowardZero=*/false, Ty);
+                                             /*roundTowardZero=*/false, Ty,
+                                             /*IsSigned*/true);
         break;
       case Intrinsic::x86_sse_cvttss2si:
       case Intrinsic::x86_sse_cvttss2si64:
@@ -1858,7 +1923,8 @@ Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
         if (ConstantFP *FPOp =
                 dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
           return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
-                                             /*roundTowardZero=*/true, Ty);
+                                             /*roundTowardZero=*/true, Ty,
+                                             /*IsSigned*/true);
         break;
       }
     }
@@ -1899,6 +1965,18 @@ Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
           return ConstantFP::get(Ty->getContext(), maxnum(C1, C2));
         }
 
+        if (IntrinsicID == Intrinsic::minimum) {
+          const APFloat &C1 = Op1->getValueAPF();
+          const APFloat &C2 = Op2->getValueAPF();
+          return ConstantFP::get(Ty->getContext(), minimum(C1, C2));
+        }
+
+        if (IntrinsicID == Intrinsic::maximum) {
+          const APFloat &C1 = Op1->getValueAPF();
+          const APFloat &C2 = Op2->getValueAPF();
+          return ConstantFP::get(Ty->getContext(), maximum(C1, C2));
+        }
+
         if (!TLI)
           return nullptr;
         if ((Name == "pow" && TLI->has(LibFunc_pow)) ||
@@ -1931,58 +2009,149 @@ Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
       return nullptr;
     }
 
-    if (auto *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
-      if (auto *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
+    if (Operands[0]->getType()->isIntegerTy() &&
+        Operands[1]->getType()->isIntegerTy()) {
+      const APInt *C0, *C1;
+      if (!getConstIntOrUndef(Operands[0], C0) ||
+          !getConstIntOrUndef(Operands[1], C1))
+        return nullptr;
+
+      switch (IntrinsicID) {
+      default: break;
+      case Intrinsic::smul_with_overflow:
+      case Intrinsic::umul_with_overflow:
+        // Even if both operands are undef, we cannot fold muls to undef
+        // in the general case. For example, on i2 there are no inputs
+        // that would produce { i2 -1, i1 true } as the result.
+        if (!C0 || !C1)
+          return Constant::getNullValue(Ty);
+        LLVM_FALLTHROUGH;
+      case Intrinsic::sadd_with_overflow:
+      case Intrinsic::uadd_with_overflow:
+      case Intrinsic::ssub_with_overflow:
+      case Intrinsic::usub_with_overflow: {
+        if (!C0 || !C1)
+          return UndefValue::get(Ty);
+
+        APInt Res;
+        bool Overflow;
         switch (IntrinsicID) {
-        default: break;
+        default: llvm_unreachable("Invalid case");
         case Intrinsic::sadd_with_overflow:
+          Res = C0->sadd_ov(*C1, Overflow);
+          break;
         case Intrinsic::uadd_with_overflow:
+          Res = C0->uadd_ov(*C1, Overflow);
+          break;
         case Intrinsic::ssub_with_overflow:
+          Res = C0->ssub_ov(*C1, Overflow);
+          break;
         case Intrinsic::usub_with_overflow:
+          Res = C0->usub_ov(*C1, Overflow);
+          break;
         case Intrinsic::smul_with_overflow:
-        case Intrinsic::umul_with_overflow: {
-          APInt Res;
-          bool Overflow;
-          switch (IntrinsicID) {
-          default: llvm_unreachable("Invalid case");
-          case Intrinsic::sadd_with_overflow:
-            Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
-            break;
-          case Intrinsic::uadd_with_overflow:
-            Res = Op1->getValue().uadd_ov(Op2->getValue(), Overflow);
-            break;
-          case Intrinsic::ssub_with_overflow:
-            Res = Op1->getValue().ssub_ov(Op2->getValue(), Overflow);
-            break;
-          case Intrinsic::usub_with_overflow:
-            Res = Op1->getValue().usub_ov(Op2->getValue(), Overflow);
-            break;
-          case Intrinsic::smul_with_overflow:
-            Res = Op1->getValue().smul_ov(Op2->getValue(), Overflow);
-            break;
-          case Intrinsic::umul_with_overflow:
-            Res = Op1->getValue().umul_ov(Op2->getValue(), Overflow);
-            break;
-          }
-          Constant *Ops[] = {
-            ConstantInt::get(Ty->getContext(), Res),
-            ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
-          };
-          return ConstantStruct::get(cast<StructType>(Ty), Ops);
-        }
-        case Intrinsic::cttz:
-          if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef.
-            return UndefValue::get(Ty);
-          return ConstantInt::get(Ty, Op1->getValue().countTrailingZeros());
-        case Intrinsic::ctlz:
-          if (Op2->isOne() && Op1->isZero()) // ctlz(0, 1) is undef.
-            return UndefValue::get(Ty);
-          return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros());
+          Res = C0->smul_ov(*C1, Overflow);
+          break;
+        case Intrinsic::umul_with_overflow:
+          Res = C0->umul_ov(*C1, Overflow);
+          break;
         }
+        Constant *Ops[] = {
+          ConstantInt::get(Ty->getContext(), Res),
+          ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
+        };
+        return ConstantStruct::get(cast<StructType>(Ty), Ops);
+      }
+      case Intrinsic::uadd_sat:
+      case Intrinsic::sadd_sat:
+        if (!C0 && !C1)
+          return UndefValue::get(Ty);
+        if (!C0 || !C1)
+          return Constant::getAllOnesValue(Ty);
+        if (IntrinsicID == Intrinsic::uadd_sat)
+          return ConstantInt::get(Ty, C0->uadd_sat(*C1));
+        else
+          return ConstantInt::get(Ty, C0->sadd_sat(*C1));
+      case Intrinsic::usub_sat:
+      case Intrinsic::ssub_sat:
+        if (!C0 && !C1)
+          return UndefValue::get(Ty);
+        if (!C0 || !C1)
+          return Constant::getNullValue(Ty);
+        if (IntrinsicID == Intrinsic::usub_sat)
+          return ConstantInt::get(Ty, C0->usub_sat(*C1));
+        else
+          return ConstantInt::get(Ty, C0->ssub_sat(*C1));
+      case Intrinsic::cttz:
+      case Intrinsic::ctlz:
+        assert(C1 && "Must be constant int");
+
+        // cttz(0, 1) and ctlz(0, 1) are undef.
+        if (C1->isOneValue() && (!C0 || C0->isNullValue()))
+          return UndefValue::get(Ty);
+        if (!C0)
+          return Constant::getNullValue(Ty);
+        if (IntrinsicID == Intrinsic::cttz)
+          return ConstantInt::get(Ty, C0->countTrailingZeros());
+        else
+          return ConstantInt::get(Ty, C0->countLeadingZeros());
       }
 
       return nullptr;
     }
+
+    // Support ConstantVector in case we have an Undef in the top.
+    if ((isa<ConstantVector>(Operands[0]) ||
+         isa<ConstantDataVector>(Operands[0])) &&
+        // Check for default rounding mode.
+        // FIXME: Support other rounding modes?
+        isa<ConstantInt>(Operands[1]) &&
+        cast<ConstantInt>(Operands[1])->getValue() == 4) {
+      auto *Op = cast<Constant>(Operands[0]);
+      switch (IntrinsicID) {
+      default: break;
+      case Intrinsic::x86_avx512_vcvtss2si32:
+      case Intrinsic::x86_avx512_vcvtss2si64:
+      case Intrinsic::x86_avx512_vcvtsd2si32:
+      case Intrinsic::x86_avx512_vcvtsd2si64:
+        if (ConstantFP *FPOp =
+                dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
+          return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
+                                             /*roundTowardZero=*/false, Ty,
+                                             /*IsSigned*/true);
+        break;
+      case Intrinsic::x86_avx512_vcvtss2usi32:
+      case Intrinsic::x86_avx512_vcvtss2usi64:
+      case Intrinsic::x86_avx512_vcvtsd2usi32:
+      case Intrinsic::x86_avx512_vcvtsd2usi64:
+        if (ConstantFP *FPOp =
+                dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
+          return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
+                                             /*roundTowardZero=*/false, Ty,
+                                             /*IsSigned*/false);
+        break;
+      case Intrinsic::x86_avx512_cvttss2si:
+      case Intrinsic::x86_avx512_cvttss2si64:
+      case Intrinsic::x86_avx512_cvttsd2si:
+      case Intrinsic::x86_avx512_cvttsd2si64:
+        if (ConstantFP *FPOp =
+                dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
+          return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
+                                             /*roundTowardZero=*/true, Ty,
+                                             /*IsSigned*/true);
+        break;
+      case Intrinsic::x86_avx512_cvttss2usi:
+      case Intrinsic::x86_avx512_cvttss2usi64:
+      case Intrinsic::x86_avx512_cvttsd2usi:
+      case Intrinsic::x86_avx512_cvttsd2usi64:
+        if (ConstantFP *FPOp =
+                dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
+          return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
+                                             /*roundTowardZero=*/true, Ty,
+                                             /*IsSigned*/false);
+        break;
+      }
+    }
     return nullptr;
   }
 
@@ -2010,6 +2179,36 @@ Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
     }
   }
 
+  if (IntrinsicID == Intrinsic::fshl || IntrinsicID == Intrinsic::fshr) {
+    const APInt *C0, *C1, *C2;
+    if (!getConstIntOrUndef(Operands[0], C0) ||
+        !getConstIntOrUndef(Operands[1], C1) ||
+        !getConstIntOrUndef(Operands[2], C2))
+      return nullptr;
+
+    bool IsRight = IntrinsicID == Intrinsic::fshr;
+    if (!C2)
+      return Operands[IsRight ? 1 : 0];
+    if (!C0 && !C1)
+      return UndefValue::get(Ty);
+
+    // The shift amount is interpreted as modulo the bitwidth. If the shift
+    // amount is effectively 0, avoid UB due to oversized inverse shift below.
+    unsigned BitWidth = C2->getBitWidth();
+    unsigned ShAmt = C2->urem(BitWidth);
+    if (!ShAmt)
+      return Operands[IsRight ? 1 : 0];
+
+    // (C0 << ShlAmt) | (C1 >> LshrAmt)
+    unsigned LshrAmt = IsRight ? ShAmt : BitWidth - ShAmt;
+    unsigned ShlAmt = !IsRight ? ShAmt : BitWidth - ShAmt;
+    if (!C0)
+      return ConstantInt::get(Ty, C1->lshr(LshrAmt));
+    if (!C1)
+      return ConstantInt::get(Ty, C0->shl(ShlAmt));
+    return ConstantInt::get(Ty, C0->shl(ShlAmt) | C1->lshr(LshrAmt));
+  }
+
   return nullptr;
 }