From ec185d074d50cc9e8af23605862d5fa0a87851dc Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Wed, 23 Dec 2015 09:58:41 +0000
Subject: [PATCH] [OperandBundles] Have InstCombine play nice with operand
 bundles

Don't assume a call's use corresponds to an argument operand, it might
correspond to a bundle operand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256327 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/IR/CallSite.h                    | 25 +++++++++++++++++++
 .../InstCombineLoadStoreAlloca.cpp            | 10 +++++---
 test/Transforms/InstCombine/alloca.ll         | 11 ++++++++
 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/include/llvm/IR/CallSite.h b/include/llvm/IR/CallSite.h
index a0ff2cb6c7e..40145af67e8 100644
--- a/include/llvm/IR/CallSite.h
+++ b/include/llvm/IR/CallSite.h
@@ -143,6 +143,16 @@ public:
            OperandNo < getBundleOperandsEndIndex();
   }
 
+  /// \brief Determine whether the passed iterator points to a data operand.
+  bool isDataOperand(Value::const_user_iterator UI) const {
+    return isDataOperand(&UI.getUse());
+  }
+
+  /// \brief Determine whether the passed use points to a data operand.
+  bool isDataOperand(const Use *U) const {
+    return data_operands_begin() <= U && U < data_operands_end();
+  }
+
   ValTy *getArgument(unsigned ArgNo) const {
     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
     return *(arg_begin() + ArgNo);
@@ -178,6 +188,21 @@ public:
   bool arg_empty() const { return arg_end() == arg_begin(); }
   unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
 
+  /// Given a value use iterator, returns the data operand that corresponds to
+  /// it.
+  /// Iterator must actually correspond to a data operand.
+  unsigned getDataOperandNo(Value::const_user_iterator UI) const {
+    return getDataOperandNo(&UI.getUse());
+  }
+
+  /// Given a use for a data operand, get the data operand number that
+  /// corresponds to it.
+  unsigned getDataOperandNo(const Use *U) const {
+    assert(getInstruction() && "Not a call or invoke instruction!");
+    assert(isDataOperand(U) && "Data operand # out of range!");
+    return U - data_operands_begin();
+  }
+
   /// Type of iterator to use when looping over data operands at this call site
   /// (see below).
   typedef IterTy data_operand_iterator;
diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index aca014f04cd..47406b9a163 100644
--- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -91,21 +91,23 @@ isOnlyCopiedFromConstantGlobal(Value *V, MemTransferInst *&TheCopy,
         if (CS.isCallee(&U))
           continue;
 
+        unsigned DataOpNo = CS.getDataOperandNo(&U);
+        bool IsArgOperand = CS.isArgOperand(&U);
+
         // Inalloca arguments are clobbered by the call.
-        unsigned ArgNo = CS.getArgumentNo(&U);
-        if (CS.isInAllocaArgument(ArgNo))
+        if (IsArgOperand && CS.isInAllocaArgument(DataOpNo))
           return false;
 
         // If this is a readonly/readnone call site, then we know it is just a
         // load (but one that potentially returns the value itself), so we can
         // ignore it if we know that the value isn't captured.
         if (CS.onlyReadsMemory() &&
-            (CS.getInstruction()->use_empty() || CS.doesNotCapture(ArgNo)))
+            (CS.getInstruction()->use_empty() || CS.doesNotCapture(DataOpNo)))
           continue;
 
         // If this is being passed as a byval argument, the caller is making a
         // copy, so it is only a read of the alloca.
-        if (CS.isByValArgument(ArgNo))
+        if (IsArgOperand && CS.isByValArgument(DataOpNo))
           continue;
       }
 
diff --git a/test/Transforms/InstCombine/alloca.ll b/test/Transforms/InstCombine/alloca.ll
index b61b75e9f9f..2ee0372e5e0 100644
--- a/test/Transforms/InstCombine/alloca.ll
+++ b/test/Transforms/InstCombine/alloca.ll
@@ -163,3 +163,14 @@ entry:
   call void (...) @use(i1* %v32, i1* %v64, i1* %v33)
   ret void
 }
+
+define void @test11() {
+entry:
+; ALL-LABEL: @test11(
+; ALL: %y = alloca i32
+; ALL: call void (...) @use(i32* nonnull @int) [ "blah"(i32* %y) ]
+; ALL: ret void
+  %y = alloca i32
+  call void (...) @use(i32* nonnull @int) [ "blah"(i32* %y) ]
+  ret void
+}
-- 
2.34.1