[IR] Unify max alignment for arguments with generic max align. (#99257)

The 2^14 limit was completely arbitrary; the generic limit is still
arbitrary, but at least it's the same arbitrary limit as everything
else.

While I'm here, also add a verifier check for the ByValOrByRefSize.

1 files changed, 23 insertions, 15 deletions

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 75a53c1..c5c4076 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -324,13 +324,6 @@ namespace {
 
 class Verifier : public InstVisitor<Verifier>, VerifierSupport {
   friend class InstVisitor<Verifier>;
-
-  // ISD::ArgFlagsTy::MemAlign only have 4 bits for alignment, so
-  // the alignment size should not exceed 2^15. Since encode(Align)
-  // would plus the shift value by 1, the alignment size should
-  // not exceed 2^14, otherwise it can NOT be properly lowered
-  // in backend.
-  static constexpr unsigned ParamMaxAlignment = 1 << 14;
   DominatorTree DT;
 
   /// When verifying a basic block, keep track of all of the
@@ -2021,31 +2014,43 @@ void Verifier::verifyParameterAttrs(AttributeSet Attrs, Type *Ty,
   }
 
   if (isa<PointerType>(Ty)) {
+    if (Attrs.hasAttribute(Attribute::Alignment)) {
+      Align AttrAlign = Attrs.getAlignment().valueOrOne();
+      Check(AttrAlign.value() <= Value::MaximumAlignment,
+            "huge alignment values are unsupported", V);
+    }
     if (Attrs.hasAttribute(Attribute::ByVal)) {
-      if (Attrs.hasAttribute(Attribute::Alignment)) {
-        Align AttrAlign = Attrs.getAlignment().valueOrOne();
-        Align MaxAlign(ParamMaxAlignment);
-        Check(AttrAlign <= MaxAlign,
-              "Attribute 'align' exceed the max size 2^14", V);
-      }
       SmallPtrSet<Type *, 4> Visited;
       Check(Attrs.getByValType()->isSized(&Visited),
             "Attribute 'byval' does not support unsized types!", V);
+      Check(DL.getTypeAllocSize(Attrs.getByValType()).getKnownMinValue() <
+                (1ULL << 32),
+            "huge 'byval' arguments are unsupported", V);
     }
     if (Attrs.hasAttribute(Attribute::ByRef)) {
       SmallPtrSet<Type *, 4> Visited;
       Check(Attrs.getByRefType()->isSized(&Visited),
             "Attribute 'byref' does not support unsized types!", V);
+      Check(DL.getTypeAllocSize(Attrs.getByRefType()).getKnownMinValue() <
+                (1ULL << 32),
+            "huge 'byref' arguments are unsupported", V);
     }
     if (Attrs.hasAttribute(Attribute::InAlloca)) {
       SmallPtrSet<Type *, 4> Visited;
       Check(Attrs.getInAllocaType()->isSized(&Visited),
             "Attribute 'inalloca' does not support unsized types!", V);
+      Check(DL.getTypeAllocSize(Attrs.getInAllocaType()).getKnownMinValue() <
+                (1ULL << 32),
+            "huge 'inalloca' arguments are unsupported", V);
     }
     if (Attrs.hasAttribute(Attribute::Preallocated)) {
       SmallPtrSet<Type *, 4> Visited;
       Check(Attrs.getPreallocatedType()->isSized(&Visited),
             "Attribute 'preallocated' does not support unsized types!", V);
+      Check(
+          DL.getTypeAllocSize(Attrs.getPreallocatedType()).getKnownMinValue() <
+              (1ULL << 32),
+          "huge 'preallocated' arguments are unsupported", V);
     }
   }
 
@@ -3511,12 +3516,15 @@ void Verifier::visitCallBase(CallBase &Call) {
         "not allowed. Please use the @llvm.amdgpu.cs.chain intrinsic instead.",
         Call);
 
+  // Disallow passing/returning values with alignment higher than we can
+  // represent.
+  // FIXME: Consider making DataLayout cap the alignment, so this isn't
+  // necessary.
   auto VerifyTypeAlign = [&](Type *Ty, const Twine &Message) {
     if (!Ty->isSized())
       return;
     Align ABIAlign = DL.getABITypeAlign(Ty);
-    Align MaxAlign(ParamMaxAlignment);
-    Check(ABIAlign <= MaxAlign,
+    Check(ABIAlign.value() <= Value::MaximumAlignment,
           "Incorrect alignment of " + Message + " to called function!", Call);
   };