[PATCH] D42653: [RS4GC] Handle call/invoke instructions as base defining values of vectors

[Daniel Neilson via Phabricator via llvm-commits]

dneilson created this revision.
dneilson added reviewers: DaniilSuchkov, anna.

There's an asymmetry in the definitions of findBaseDefiningValueOfVector() and
findBaseDefiningValue() of RS4GC. The later handles call and invoke instructions,
and the former does not. This appears to be simple oversight. This patch remedies
the oversight by adding the call and invoke cases to findBaseDefiningValueOfVector().


Repository:
  rL LLVM

https://reviews.llvm.org/D42653

Files:
  lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
  test/Transforms/RewriteStatepointsForGC/base-vector.ll


Index: test/Transforms/RewriteStatepointsForGC/base-vector.ll
===================================================================
--- test/Transforms/RewriteStatepointsForGC/base-vector.ll
+++ test/Transforms/RewriteStatepointsForGC/base-vector.ll
@@ -261,3 +261,19 @@
   call void @use_vec(<4 x i64 addrspace(1) *> %vec2)
   ret void
 }
+
+declare <4 x i64 addrspace(1)*> @def_vec() "gc-leaf-function"
+
+define void @test12(<4 x i64 addrspace(1)*> %vec1) gc "statepoint-example" {
+; CHECK-LABEL: @test12(
+; CHECK: @llvm.experimental.gc.statepoint.p0f_isVoidf{{.*}}<4 x i64 addrspace(1)*> %vec)
+; CHECK-NEXT: %vec.relocated = call coldcc <4 x i8 addrspace(1)*> @llvm.experimental.gc.relocate.v4p1i8(
+; CHECK-NEXT: %vec.relocated.casted = bitcast <4 x i8 addrspace(1)*> %vec.relocated to <4 x i64 addrspace(1)*>
+; CHECK-NEXT: call void @use_vec(<4 x i64 addrspace(1)*> %vec.relocated.casted)
+; CHECK-NEXT: ret void
+entry:
+  %vec = call <4 x i64 addrspace(1)*> @def_vec()
+  call void @do_safepoint() [ "deopt"() ]
+  call void @use_vec(<4 x i64 addrspace(1)*> %vec)
+  ret void
+}
Index: lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
===================================================================
--- lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
+++ lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
@@ -476,6 +476,12 @@
   if (auto *BC = dyn_cast<BitCastInst>(I))
     return findBaseDefiningValue(BC->getOperand(0));
 
+  // We assume that functions in the source language only return base
+  // pointers.  This should probably be generalized via attributes to support
+  // both source language and internal functions.
+  if (isa<CallInst>(I) || isa<InvokeInst>(I))
+    return BaseDefiningValueResult(I, true);
+
   // A PHI or Select is a base defining value.  The outer findBasePointer
   // algorithm is responsible for constructing a base value for this BDV.
   assert((isa<SelectInst>(I) || isa<PHINode>(I)) &&


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