[APInt] Fix APInt constructions where value does not fit bitwidth (NFCI) (#80309)

This fixes all the places that hit the new assertion added in
https://github.com/llvm/llvm-project/pull/106524 in tests. That is,
cases where the value passed to the APInt constructor is not an N-bit
signed/unsigned integer, where N is the bit width and signedness is
determined by the isSigned flag.

The fixes either set the correct value for isSigned, set the
implicitTrunc flag, or perform more calculations inside APInt.

Note that the assertion is currently still disabled by default, so this
patch is mostly NFC.

4 files changed, 7 insertions, 6 deletions

diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 3af4ae3..da0fd1f 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -888,7 +888,8 @@ Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
   APInt Offset = APInt(
       BitWidth,
       DL.getIndexedOffsetInType(
-          SrcElemTy, ArrayRef((Value *const *)Ops.data() + 1, Ops.size() - 1)));
+          SrcElemTy, ArrayRef((Value *const *)Ops.data() + 1, Ops.size() - 1)),
+      /*isSigned=*/true, /*implicitTrunc=*/true);
 
   std::optional<ConstantRange> InRange = GEP->getInRange();
   if (InRange)
diff --git a/llvm/lib/Analysis/Loads.cpp b/llvm/lib/Analysis/Loads.cpp
index f4b2027..820b8e9 100644
--- a/llvm/lib/Analysis/Loads.cpp
+++ b/llvm/lib/Analysis/Loads.cpp
@@ -95,10 +95,8 @@ static bool isDereferenceableAndAlignedPointer(
 
   auto IsKnownDeref = [&]() {
     bool CheckForNonNull, CheckForFreed;
-    APInt KnownDerefBytes(Size.getBitWidth(),
-                          V->getPointerDereferenceableBytes(DL, CheckForNonNull,
-                                                            CheckForFreed));
-    if (!KnownDerefBytes.getBoolValue() || !KnownDerefBytes.uge(Size) ||
+    if (!Size.ule(V->getPointerDereferenceableBytes(DL, CheckForNonNull,
+                                                    CheckForFreed)) ||
         CheckForFreed)
       return false;
     if (CheckForNonNull &&
diff --git a/llvm/lib/Analysis/MemoryBuiltins.cpp b/llvm/lib/Analysis/MemoryBuiltins.cpp
index e1abf5e..dc2dc4c 100644
--- a/llvm/lib/Analysis/MemoryBuiltins.cpp
+++ b/llvm/lib/Analysis/MemoryBuiltins.cpp
@@ -767,6 +767,8 @@ SizeOffsetAPInt ObjectSizeOffsetVisitor::visitAllocaInst(AllocaInst &I) {
   TypeSize ElemSize = DL.getTypeAllocSize(I.getAllocatedType());
   if (ElemSize.isScalable() && Options.EvalMode != ObjectSizeOpts::Mode::Min)
     return ObjectSizeOffsetVisitor::unknown();
+  if (!isUIntN(IntTyBits, ElemSize.getKnownMinValue()))
+    return ObjectSizeOffsetVisitor::unknown();
   APInt Size(IntTyBits, ElemSize.getKnownMinValue());
   if (!I.isArrayAllocation())
     return SizeOffsetAPInt(align(Size, I.getAlign()), Zero);
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index a3ba8e0..3d028ab 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -6883,7 +6883,7 @@ const ConstantRange &ScalarEvolution::getRangeRef(
       bool CanBeNull, CanBeFreed;
       uint64_t DerefBytes =
           V->getPointerDereferenceableBytes(DL, CanBeNull, CanBeFreed);
-      if (DerefBytes > 1) {
+      if (DerefBytes > 1 && isUIntN(BitWidth, DerefBytes)) {
         // The highest address the object can start is DerefBytes bytes before
         // the end (unsigned max value). If this value is not a multiple of the
         // alignment, the last possible start value is the next lowest multiple