[PATCH] D53602: [IRVerifier] Allow StructRet in statepoint

[Cherry Zhang via Phabricator via llvm-commits]

cherry created this revision.
cherry added a reviewer: thanm.
Herald added a subscriber: llvm-commits.

StructRet attribute is not allowed in vararg calls. The statepoint
intrinsic is vararg, but the wrapped function may be not. Allow
calls of statepoint with StructRet arg, as long as the wrapped
function is not vararg.


Repository:
  rL LLVM

https://reviews.llvm.org/D53602

Files:
  lib/IR/Verifier.cpp
  test/Verifier/statepoint.ll


Index: test/Verifier/statepoint.ll
===================================================================
--- test/Verifier/statepoint.ll
+++ test/Verifier/statepoint.ll
@@ -4,6 +4,7 @@
 declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32, i32)
 declare i64 addrspace(1)* @llvm.experimental.gc.relocate.p1i64(token, i32, i32)
 declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
+declare token @llvm.experimental.gc.statepoint.p0f_isVoidp0s_structsf(i64, i32, void (%struct*)*, i32, i32, ...)
 declare i32 @"personality_function"()
 
 ;; Basic usage
@@ -79,3 +80,20 @@
   %obj1.relocated1 = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %landing_pad, i32 12, i32 12)
   ret i8 addrspace(1)* %obj1.relocated1
 }
+
+; Test for statepoint with sret attribute.
+; This should be allowed as long as the wrapped function is not vararg.
+%struct = type { i64, i64, i64 }
+
+declare void @fn_sret(%struct* sret)
+
+define void @test_sret() gc "statepoint-example" {
+  %x = alloca %struct
+  %statepoint_token = call token (i64, i32, void (%struct*)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidp0s_structsf(i64 0, i32 0, void (%struct*)* @fn_sret, i32 1, i32 0, %struct* sret %x, i32 0, i32 0)
+  ret void
+  ; CHECK-LABEL: test_sret
+  ; CHECK: alloca
+  ; CHECK: statepoint
+  ; CHECK-SAME: sret
+  ; CHECK: ret
+}
Index: lib/IR/Verifier.cpp
===================================================================
--- lib/IR/Verifier.cpp
+++ lib/IR/Verifier.cpp
@@ -1929,13 +1929,20 @@
 
   // Verify that the types of the call parameter arguments match
   // the type of the wrapped callee.
+  AttributeList Attrs = CS.getAttributes();
   for (int i = 0; i < NumParams; i++) {
     Type *ParamType = TargetFuncType->getParamType(i);
     Type *ArgType = CS.getArgument(5 + i)->getType();
     Assert(ArgType == ParamType,
            "gc.statepoint call argument does not match wrapped "
            "function type",
            &CI);
+
+    if (TargetFuncType->isVarArg()) {
+      AttributeSet ArgAttrs = Attrs.getParamAttributes(5 + i);
+      Assert(!ArgAttrs.hasAttribute(Attribute::StructRet),
+             "Attribute 'sret' cannot be used for vararg call arguments!", &CI);
+    }
   }
 
   const int EndCallArgsInx = 4 + NumCallArgs;
@@ -2813,8 +2820,13 @@
         SawReturned = true;
       }
 
-      Assert(!ArgAttrs.hasAttribute(Attribute::StructRet),
-             "Attribute 'sret' cannot be used for vararg call arguments!", I);
+      // Statepoint intrinsic is vararg but the wrapped function may be not.
+      // Allow sret here and check the wrapped function in verifyStatepoint.
+      if (CS.getCalledFunction() == nullptr ||
+          CS.getCalledFunction()->getIntrinsicID() !=
+            Intrinsic::experimental_gc_statepoint)
+        Assert(!ArgAttrs.hasAttribute(Attribute::StructRet),
+               "Attribute 'sret' cannot be used for vararg call arguments!", I);
 
       if (ArgAttrs.hasAttribute(Attribute::InAlloca))
         Assert(Idx == CS.arg_size() - 1, "inalloca isn't on the last argument!",


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