[PATCH] D121898: [Verifier] Verify parameter alignment.

[LuoYuanke via Phabricator via llvm-commits]

LuoYuanke created this revision.
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In DAGISel, the parameter alignment only have 4 bits to hold the value.
The encode(alignment) would need extra 1 bit, so the max aligment that
ISel can support is 2^14. This patch verify the parameter, return value
and align attribute for parameter.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D121898

Files:
  llvm/lib/IR/Verifier.cpp
  llvm/test/Verifier/param-align.ll
  llvm/test/Verifier/param-attr-align.ll
  llvm/test/Verifier/param-ret-align.ll


Index: llvm/test/Verifier/param-ret-align.ll
===================================================================
--- /dev/null
+++ llvm/test/Verifier/param-ret-align.ll
@@ -0,0 +1,10 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+; CHECK: Incorrect alignment of return type to called function!
+define dso_local void @foo() {
+entry:
+  call <8192 x float> @bar()
+  ret void
+}
+
+declare dso_local <8192 x float> @bar()
Index: llvm/test/Verifier/param-attr-align.ll
===================================================================
--- /dev/null
+++ llvm/test/Verifier/param-attr-align.ll
@@ -0,0 +1,11 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+; CHECK: Attribute 'align 32768' exceed the max size 2^14
+define dso_local void @foo(i8* %p) {
+entry:
+  %p1 = bitcast i8* %p to <8 x float>* 
+  call void @bar(<8 x float>* noundef byval(<8 x float>) align 32768 %p1)
+  ret void
+}
+
+declare dso_local void @bar(<8 x float>* %p)
Index: llvm/test/Verifier/param-align.ll
===================================================================
--- /dev/null
+++ llvm/test/Verifier/param-align.ll
@@ -0,0 +1,10 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+; CHECK: Incorrect alignment of argument passed to called function!
+define dso_local void @foo(<8192 x float> noundef %vec) {
+entry:
+  call void @bar(<8192 x float> %vec)
+  ret void
+}
+
+declare dso_local void @bar(<8192 x float>)
Index: llvm/lib/IR/Verifier.cpp
===================================================================
--- llvm/lib/IR/Verifier.cpp
+++ llvm/lib/IR/Verifier.cpp
@@ -1731,12 +1731,23 @@
 
   verifyAttributeTypes(Attrs, V);
 
-  for (Attribute Attr : Attrs)
+  for (Attribute Attr : Attrs) {
     Assert(Attr.isStringAttribute() ||
            Attribute::canUseAsParamAttr(Attr.getKindAsEnum()),
            "Attribute '" + Attr.getAsString() +
                "' does not apply to parameters",
            V);
+    if (Attr.getKindAsEnum() == Attribute::Alignment) {
+      Align AttrAlign = Attr.getAlignment().valueOrOne();
+      // ArgFlagsTy::MemAlign only have 4 bits for alignment, so the
+      // alignment size should not exceed 1 << 14, otherwise it can NOT
+      // be properly lowered.
+      Align MaxAlign(1 << 15);
+      Assert(AttrAlign < MaxAlign,
+             "Attribute '" + Attr.getAsString() + "' exceed the max size 2^14",
+             V);
+    }
+  }
 
   if (Attrs.hasAttribute(Attribute::ImmArg)) {
     Assert(Attrs.getNumAttributes() == 1,
@@ -3142,6 +3153,24 @@
   Assert(verifyAttributeCount(Attrs, Call.arg_size()),
          "Attribute after last parameter!", Call);
 
+  auto VerifyTypeAlign = [&](Type *Ty, const Twine &Message) {
+    if (!Ty->isSized())
+      return;
+    Align ABIAlign = DL.getABITypeAlign(Ty);
+    // ArgFlagsTy::MemAlign only have 4 bits for alignment, so the
+    // alignment size should not exceed 1 << 14, otherwise it can NOT
+    // be properly lowered.
+    Align MaxAlign(1 << 15);
+    Assert(ABIAlign < MaxAlign,
+           "Incorrect alignment of " + Message + " to called function!", Call);
+  };
+
+  VerifyTypeAlign(FTy->getReturnType(), "return type");
+  for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
+    Type *Ty = FTy->getParamType(i);
+    VerifyTypeAlign(Ty, "argument passed");
+  }
+
   Function *Callee =
       dyn_cast<Function>(Call.getCalledOperand()->stripPointerCasts());
   bool IsIntrinsic = Callee && Callee->isIntrinsic();


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