[PATCH] D117591: A readonly operand bundle should not prevent inference of readonly from a readnone callee

[Philip Reames via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG31c0e52420bb: A readonly operand bundle should not prevent inference of readonly from a… (authored by reames).

Changed prior to commit:
  https://reviews.llvm.org/D117591?vs=400920&id=400961#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D117591/new/

https://reviews.llvm.org/D117591

Files:
  llvm/include/llvm/IR/InstrTypes.h
  llvm/test/Transforms/InstCombine/trivial-dse-calls.ll


Index: llvm/test/Transforms/InstCombine/trivial-dse-calls.ll
===================================================================
--- llvm/test/Transforms/InstCombine/trivial-dse-calls.ll
+++ llvm/test/Transforms/InstCombine/trivial-dse-calls.ll
@@ -253,7 +253,6 @@
 
 define void @test_readnone_with_deopt() {
 ; CHECK-LABEL: @test_readnone_with_deopt(
-; CHECK-NEXT:    call void @removable_readnone() [ "deopt"() ]
 ; CHECK-NEXT:    ret void
 ;
   call void @removable_readnone() [ "deopt"() ]
Index: llvm/include/llvm/IR/InstrTypes.h
===================================================================
--- llvm/include/llvm/IR/InstrTypes.h
+++ llvm/include/llvm/IR/InstrTypes.h
@@ -1818,14 +1818,14 @@
 
   /// Determine if the call does not access or only reads memory.
   bool onlyReadsMemory() const {
-    return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
+    return hasImpliedFnAttr(Attribute::ReadOnly);
   }
 
   void setOnlyReadsMemory() { addFnAttr(Attribute::ReadOnly); }
 
   /// Determine if the call does not access or only writes memory.
   bool onlyWritesMemory() const {
-    return doesNotAccessMemory() || hasFnAttr(Attribute::WriteOnly);
+    return hasImpliedFnAttr(Attribute::WriteOnly);
   }
   void setOnlyWritesMemory() { addFnAttr(Attribute::WriteOnly); }
 
@@ -2288,6 +2288,26 @@
     return hasFnAttrOnCalledFunction(Kind);
   }
 
+  /// A specialized version of hasFnAttrImpl for when the caller wants to
+  /// know if an attribute's semantics are implied, not whether the attribute
+  /// is actually present.  This distinction only exists when checking whether
+  /// something is readonly or writeonly since readnone implies both.  The case
+  /// which motivates the specialized code is a callee with readnone, and an
+  /// operand bundle on the call which disallows readnone but not either
+  /// readonly or writeonly.
+  bool hasImpliedFnAttr(Attribute::AttrKind Kind) const {
+    assert((Kind == Attribute::ReadOnly || Kind == Attribute::WriteOnly) &&
+           "use hasFnAttrImpl instead");
+    if (Attrs.hasFnAttr(Kind) || Attrs.hasFnAttr(Attribute::ReadNone))
+      return true;
+
+    if (isFnAttrDisallowedByOpBundle(Kind))
+      return false;
+
+    return hasFnAttrOnCalledFunction(Kind) ||
+      hasFnAttrOnCalledFunction(Attribute::ReadNone);
+  }
+
   /// Determine whether the return value has the given attribute. Supports
   /// Attribute::AttrKind and StringRef as \p AttrKind types.
   template <typename AttrKind> bool hasRetAttrImpl(AttrKind Kind) const {


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