[cfe-commits] r152951 - in /cfe/trunk: lib/CodeGen/CGCall.cpp test/CodeGenCXX/2012-03-16-StoreAlign.cpp

[Bill Wendling]

Author: void
Date: Fri Mar 16 16:45:12 2012
New Revision: 152951

URL: http://llvm.org/viewvc/llvm-project?rev=152951&view=rev
Log:
When "low alignment" is specified, then set the alignment of the aggregate's
store to 1. This allows code-gen to select a more appropriate alignment. If left
to zero, an alignment greater than the alignment of the pointer may be selected,
causing code-gen to use instructions which require an alignment greater than the
pointer guarantees.
<rdar://problem/11043589>

Added:
    cfe/trunk/test/CodeGenCXX/2012-03-16-StoreAlign.cpp
Modified:
    cfe/trunk/lib/CodeGen/CGCall.cpp

Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=152951&r1=152950&r2=152951&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Fri Mar 16 16:45:12 2012
@@ -623,7 +623,9 @@
         SI->setAlignment(1);
     }
   } else {
-    CGF.Builder.CreateStore(Val, DestPtr, DestIsVolatile);
+    llvm::StoreInst *SI = CGF.Builder.CreateStore(Val, DestPtr, DestIsVolatile);
+    if (LowAlignment)
+      SI->setAlignment(1);
   }
 }
 

Added: cfe/trunk/test/CodeGenCXX/2012-03-16-StoreAlign.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/2012-03-16-StoreAlign.cpp?rev=152951&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/2012-03-16-StoreAlign.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/2012-03-16-StoreAlign.cpp Fri Mar 16 16:45:12 2012
@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -emit-llvm -o - -triple x86_64-apple-darwin %s | FileCheck %s
+// <rdar://problem/11043589>
+
+struct Length {
+  Length(double v) {
+    m_floatValue = static_cast<float>(v);
+  }
+
+  bool operator==(const Length& o) const {
+    return getFloatValue() == o.getFloatValue();
+  }
+  bool operator!=(const Length& o) const { return !(*this == o); }
+private:
+  float getFloatValue() const {
+    return m_floatValue;
+  }
+  float m_floatValue;
+};
+
+
+struct Foo {
+  static Length inchLength(double inch);
+  static bool getPageSizeFromName(const Length &A) {
+    static const Length legalWidth = inchLength(8.5);
+    if (A != legalWidth) return true;
+    return false;
+  }
+};
+
+// CHECK: @_ZZN3Foo19getPageSizeFromNameERK6LengthE10legalWidth = linkonce_odr global %struct.Length zeroinitializer, align 4
+// CHECK: store float %call, float* getelementptr inbounds (%struct.Length* @_ZZN3Foo19getPageSizeFromNameERK6LengthE10legalWidth, i32 0, i32 0), align 1
+
+bool bar(Length &b) {
+  Foo f;
+  return f.getPageSizeFromName(b);
+}