Merge pull request #16594 from ravikandhadai/FPToIntPR

Revert "[Diagnostics & Tests] Add diagnostics for detecting invalid conversions form Floating points to integers"

Author: ravikandhadai

include/swift/AST/DiagnosticsSIL.def

@@ -312,14 +312,6 @@ ERROR(non_borrowed_indirect_addressof,none,
 REMARK(opt_remark_passed, none, "%0", (StringRef))
 REMARK(opt_remark_missed, none, "%0", (StringRef))
 
-// Float-point to integer conversions
-ERROR(float_to_int_overflow, none,
-  "invalid%select{| implicit}2 conversion: '%0' overflows %1", (StringRef, Type, bool))
-
-ERROR(negative_fp_literal_overflow_unsigned, none,
-  "negative literal '%0' cannot be converted to %select{|unsigned }2%1",
-  (StringRef, Type, bool))
-
 #ifndef DIAG_NO_UNDEF
 # if defined(DIAG)
 #  undef DIAG

lib/SILOptimizer/Utils/ConstantFolding.cpp

@@ -20,7 +20,6 @@
 #include "swift/SILOptimizer/Utils/Local.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/ADT/APSInt.h"
 
 #define DEBUG_TYPE "constant-folding"
 
@@ -860,116 +859,6 @@ constantFoldAndCheckIntegerConversions(BuiltinInst *BI,
 
 }
 
-/// A utility function that extracts the literal text corresponding
-/// to a given FloatLiteralInst the way it appears in the AST.
-/// This function can be used on FloatLiteralInsts generated by the
-/// constant folding phase.
-/// If the extraction is successful, the function returns true and
-/// 'fpStr' contains the literal the way it appears in the AST.
-/// If the extraction is unsuccessful, e.g. because there is no AST
-/// for the FloatLiteralInst, the function returns false.
-template<unsigned N>
-static bool tryExtractLiteralText(FloatLiteralInst *flitInst,
-                                  SmallString<N> &fpStr) {
-
-  Expr *expr = flitInst->getLoc().getAsASTNode<Expr>();
-  if (!expr)
-    return false;
-
-  // 'expr' may not be a FloatLiteralExpr since 'flitInst' could have been
-  // created by the ConstantFolder by folding floating-point constructor calls.
-  // So we iterate through the sequence of folded constructors if any, and
-  // try to extract the FloatLiteralExpr.
-  while (auto *callExpr = dyn_cast<CallExpr>(expr)) {
-    if (callExpr->getNumArguments() != 1 ||
-         !dyn_cast<ConstructorRefCallExpr>(callExpr->getFn()))
-      break;
-
-    auto *tupleExpr = dyn_cast<TupleExpr>(callExpr->getArg());
-    if (!tupleExpr)
-      break;
-
-    expr = tupleExpr->getElement(0);
-  }
-
-  auto *flitExpr = dyn_cast<FloatLiteralExpr>(expr);
-  if (!flitExpr)
-    return false;
-
-  if (flitExpr->isNegative())
-    fpStr += '-';
-  fpStr += flitExpr->getDigitsText();
-  return true;
-}
-
-static SILValue foldFPToIntConversion(BuiltinInst *BI,
-      const BuiltinInfo &Builtin, Optional<bool> &ResultsInError) {
-
-  assert(Builtin.ID == BuiltinValueKind::FPToSI ||
-         Builtin.ID == BuiltinValueKind::FPToUI);
-
-  OperandValueArrayRef Args = BI->getArguments();
-  bool conversionToUnsigned = (Builtin.ID == BuiltinValueKind::FPToUI);
-
-  auto *flitInst = dyn_cast<FloatLiteralInst>(Args[0]);
-  if (!flitInst)
-    return nullptr;
-  APFloat fpVal = flitInst->getValue();
-  auto *destTy = Builtin.Types[1]->castTo<BuiltinIntegerType>();
-
-  // Check non-negativeness of 'fpVal' for conversion to unsigned int.
-  if (conversionToUnsigned && fpVal.isNegative() && !fpVal.isZero()) {
-    // Stop folding and emit diagnostics if enabled.
-    if (ResultsInError.hasValue()) {
-      SILModule &M = BI->getModule();
-      const ApplyExpr *CE = BI->getLoc().getAsASTNode<ApplyExpr>();
-
-      SmallString<10> fpStr;
-      if (!tryExtractLiteralText(flitInst, fpStr))
-        flitInst->getValue().toString(fpStr);
-
-      diagnose(M.getASTContext(), BI->getLoc().getSourceLoc(),
-               diag::negative_fp_literal_overflow_unsigned, fpStr,
-               CE ? CE->getType() : destTy,
-               CE ? false : conversionToUnsigned);
-      ResultsInError = Optional<bool>(true);
-    }
-    return nullptr;
-  }
-
-  llvm::APSInt resInt(destTy->getFixedWidth(), conversionToUnsigned);
-  bool isExact = false;
-  APFloat::opStatus status =
-    fpVal.convertToInteger(resInt, APFloat::rmTowardZero, &isExact);
-
-  if (status & APFloat::opStatus::opInvalidOp) {
-    // Stop folding and emit diagnostics if enabled.
-    if (ResultsInError.hasValue()) {
-      SILModule &M = BI->getModule();
-      const ApplyExpr *CE = BI->getLoc().getAsASTNode<ApplyExpr>();
-
-      SmallString<10> fpStr;
-      if (!tryExtractLiteralText(flitInst, fpStr))
-        flitInst->getValue().toString(fpStr);
-
-      diagnose(M.getASTContext(), BI->getLoc().getSourceLoc(),
-               diag::float_to_int_overflow, fpStr,
-               CE ? CE->getType() : destTy,
-               CE ? CE->isImplicit() : false);
-      ResultsInError = Optional<bool>(true);
-    }
-    return nullptr;
-  }
-
-  if (status != APFloat::opStatus::opOK &&
-      status != APFloat::opStatus::opInexact) {
-    return nullptr;
-  }
-  // The call to the builtin should be replaced with the constant value.
-  SILBuilderWithScope B(BI);
-  return B.createIntegerLiteral(BI->getLoc(), BI->getType(), resInt);
-}
-
 static SILValue constantFoldBuiltin(BuiltinInst *BI,
                                     Optional<bool> &ResultsInError) {
   const IntrinsicInfo &Intrinsic = BI->getIntrinsicInfo();
@@ -1100,12 +989,6 @@ case BuiltinValueKind::id:
     return B.createFloatLiteral(Loc, BI->getType(), TruncVal);
   }
 
-  // Conversions from floating point to integer,
-  case BuiltinValueKind::FPToSI:
-  case BuiltinValueKind::FPToUI: {
-    return foldFPToIntConversion(BI, Builtin, ResultsInError);
-  }
-
   case BuiltinValueKind::AssumeNonNegative: {
     auto *V = dyn_cast<IntegerLiteralInst>(Args[0]);
     if (!V)