[cfe-commits] r108884 - /cfe/trunk/lib/CodeGen/CGExprCXX.cpp

[Chris Lattner]

Author: lattner
Date: Tue Jul 20 13:49:33 2010
New Revision: 108884

URL: http://llvm.org/viewvc/llvm-project?rev=108884&view=rev
Log:
delete a loop that just generates dead code.  In an example
like this:

void *test(long N) {
  return new int[N][42][42];
}

the loop generates two dead mul instructions:

  %tmp = load i64* %N.addr                        ; <i64> [#uses=2]
  %0 = mul i64 %tmp, 7056                         ; <i64> [#uses=1]
  %1 = mul i64 %tmp, 42                           ; <i64> [#uses=1]
  %2 = mul i64 %1, 42                             ; <i64> [#uses=0]
  %call = call noalias i8* @_Znam(i64 %0)         ; <i8*> [#uses=1]

The scale of these multiplies is already handled by the typesize stuff.


Modified:
    cfe/trunk/lib/CodeGen/CGExprCXX.cpp

Modified: cfe/trunk/lib/CodeGen/CGExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprCXX.cpp?rev=108884&r1=108883&r2=108884&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprCXX.cpp Tue Jul 20 13:49:33 2010
@@ -440,16 +440,6 @@
     CGF.Builder.CreateMul(NumElements, 
                           llvm::ConstantInt::get(SizeTy, 
                                                  TypeSize.getQuantity()));
-  
-  while (const ArrayType *AType = Context.getAsArrayType(Type)) {
-    const llvm::ArrayType *llvmAType =
-      cast<llvm::ArrayType>(CGF.ConvertType(Type));
-    NumElements =
-      CGF.Builder.CreateMul(NumElements, 
-                            llvm::ConstantInt::get(
-                                          SizeTy, llvmAType->getNumElements()));
-    Type = AType->getElementType();
-  }
 
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