[llvm-commits] [PATCH] Fix type size calculation in CreateMalloc(), getMallocArraySize(), and isArrayMalloc()

[Victor Hernandez]

Duncan,

You are right.  My mistake also got caught by test/CodeGen/X86/x86-64- 
malloc.ll when MallocInst is avoided (not the default mode).

Instead of switching away from ConstantExpr::getSizeOf, I fixed  
isArrayMalloc() to cast ElementSize to the right size.

Here is the new patch:


thanks,
Victor

On Sep 11, 2009, at 10:08 AM, Duncan Sands wrote:

> Hi Victor,
>
>> Malloc call codegen was using ConstantExpr::getSizeOf() to  
>> determine the size of a type, when it should have been using Type->  
>> getPrimitiveSizeInBits().
>
> using ConstantExpr::getSizeOf (which is the same as getTypeAllocSize)
> was correct.  Using getPrimitiveSizeInBits is wrong, since it does not
> take alignment into account.  Consider x86 long double, which is 80  
> bits
> long (this is what getPrimitiveSizeInBits returns).  If you ask GCC  
> what
> sizeof(x86 long double) is, it will tell you 12 bytes or 16 bytes
> depending on the platform.  You should be mallocing the same number of
> bytes as sizeof gives, 12 or 16, and not 10.
>
> Ciao,
>
> Duncan.
>
>
>  Fixed that.  isArrayMalloc()now
>> correctly identifies array mallocs.
>> I also reorganized the InsertBefore vs. InsertAtEnd code in  
>> createMalloc() for clarity.
>> ------------------------------------------------------------------------
>> Victor
>> ------------------------------------------------------------------------
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>

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