From cc0442fa28e5d1f403f820dcdee49911c3e622a9 Mon Sep 17 00:00:00 2001
From: Mike Stump <mrs@apple.com>
Date: Fri, 22 May 2009 19:07:20 +0000
Subject: [PATCH] Fixup codegen for __block int i; i += rhs();.  Should also
 slightly improve codegen in some cases.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72273 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGExprScalar.cpp | 9 +++++----
 test/CodeGen/blocks-seq.c    | 9 +++++++--
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 01dd94c274..8cd84ecdb4 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -803,15 +803,16 @@ Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E,
     return llvm::UndefValue::get(CGF.ConvertType(E->getType()));
   }
 
+  // Emit the RHS first.  __block variables need to have the rhs evaluated
+  // first, plus this should improve codegen a little.
+  OpInfo.RHS = Visit(E->getRHS());
+  OpInfo.Ty = E->getComputationResultType();
+  OpInfo.E = E;
   // Load/convert the LHS.
   LValue LHSLV = EmitLValue(E->getLHS());
   OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy);
   OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy,
                                     E->getComputationLHSType());
-  // Emit the RHS.
-  OpInfo.RHS = Visit(E->getRHS());
-  OpInfo.Ty = E->getComputationResultType();
-  OpInfo.E = E;
   
   // Expand the binary operator.
   Value *Result = (this->*Func)(OpInfo);
diff --git a/test/CodeGen/blocks-seq.c b/test/CodeGen/blocks-seq.c
index eb4990a3df..f637fbc078 100644
--- a/test/CodeGen/blocks-seq.c
+++ b/test/CodeGen/blocks-seq.c
@@ -1,13 +1,18 @@
 // RUN: clang-cc -fblocks -triple x86_64-apple-darwin10 -emit-llvm -o %t %s &&
 // RUN: grep '%call = call i32 (...)\* @rhs()' %t | count 1 &&
-// If this fails, see about sliding %4 and %5...
+// If this fails, see about sliding %4, %5, %6 and %7...
 // RUN: grep '%forwarding1 = getelementptr %0\* %i, i32 0, i32 1' %t | count 1 &&
 // RUN: grep '%4 = bitcast i8\*\* %forwarding1 to %0\*\*' %t | count 1 &&
-// RUN: grep '%5 = load %0\*\* %4' %t | count 1
+// RUN: grep '%5 = load %0\*\* %4' %t | count 1 &&
+// RUN: grep '%call2 = call i32 (...)\* @rhs()' %t | count 1 &&
+// RUN: grep '%forwarding3 = getelementptr %0\* %i, i32 0, i32 1' %t | count 1 &&
+// RUN: grep '%6 = bitcast i8\*\* %forwarding3 to %0\*\*' %t | count 1 &&
+// RUN: grep '%7 = load %0\*\* %6' %t | count 1
 
 int rhs();
 
 void foo() {
   __block int i;
   i = rhs();
+  i += rhs();
 }