[cfe-commits] r166805 - in /cfe/trunk: lib/CodeGen/TargetInfo.cpp test/CodeGen/ppc64-varargs-struct.c

[Rafael Espíndola]

you should probably add a CHECK-NOT or change a CHECK to CHECK-NEXT.
The modified test would pass with the patch reverted, no?


On 26 October 2012 15:59, Bill Schmidt <wschmidt at linux.vnet.ibm.com> wrote:
> Author: wschmidt
> Date: Fri Oct 26 14:59:03 2012
> New Revision: 166805
>
> URL: http://llvm.org/viewvc/llvm-project?rev=166805&view=rev
> Log:
> This patch addresses a 64-bit PowerPC ELF ABI compatibility issue with
> varargs parameter passing.
>
> A strict reading of the ABI indicates that any argument with alignment greater
> than 8 may require skipping doublewords in the parameter save area to align
> the argument, and hence require skipping GPRs.  In practice, this is not done
> by GCC.  The alignment restriction is used for internal alignment of a
> structure, but a structure with 16-byte alignment, for example, is not
> itself 16-byte aligned in the parameter save area.  Although this is messy,
> it has become the de facto standard used in building existing libraries.
>
> My initial varargs support followed the ABI language, but not the de facto
> standard.  Running the GCC compatibility test suite exposed this issue, and
> indeed showed that LLVM didn't pass parameters self-consistently with my
> original logic.  Removing the additional alignment logic allows the affected
> tests to now pass.
>
> I modified the ppc64-varargs-struct.c test case to remove the existing test
> for generation of alignment code, which is no longer appropriate.
>
> Built and tested on powerpc64-unknown-linux-gnu with no new regressions.
>
> Modified:
>     cfe/trunk/lib/CodeGen/TargetInfo.cpp
>     cfe/trunk/test/CodeGen/ppc64-varargs-struct.c
>
> Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=166805&r1=166804&r2=166805&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original)
> +++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Fri Oct 26 14:59:03 2012
> @@ -2755,21 +2755,6 @@
>    llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
>    llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
>
> -  // Handle address alignment for type alignment > 64 bits.  Although
> -  // long double normally requires 16-byte alignment, this is not the
> -  // case when it is passed as an argument; so handle that special case.
> -  const BuiltinType *BT = Ty->getAs<BuiltinType>();
> -  unsigned TyAlign = CGF.getContext().getTypeAlign(Ty) / 8;
> -
> -  if (TyAlign > 8 && (!BT || !BT->isFloatingPoint())) {
> -    assert((TyAlign & (TyAlign - 1)) == 0 &&
> -           "Alignment is not power of 2!");
> -    llvm::Value *AddrAsInt = Builder.CreatePtrToInt(Addr, CGF.Int64Ty);
> -    AddrAsInt = Builder.CreateAdd(AddrAsInt, Builder.getInt64(TyAlign - 1));
> -    AddrAsInt = Builder.CreateAnd(AddrAsInt, Builder.getInt64(~(TyAlign - 1)));
> -    Addr = Builder.CreateIntToPtr(AddrAsInt, BP);
> -  }
> -
>    // Update the va_list pointer.
>    unsigned SizeInBytes = CGF.getContext().getTypeSize(Ty) / 8;
>    unsigned Offset = llvm::RoundUpToAlignment(SizeInBytes, 8);
>
> Modified: cfe/trunk/test/CodeGen/ppc64-varargs-struct.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/ppc64-varargs-struct.c?rev=166805&r1=166804&r2=166805&view=diff
> ==============================================================================
> --- cfe/trunk/test/CodeGen/ppc64-varargs-struct.c (original)
> +++ cfe/trunk/test/CodeGen/ppc64-varargs-struct.c Fri Oct 26 14:59:03 2012
> @@ -18,12 +18,6 @@
>  // CHECK: bitcast %struct.x* %{{[0-9]+}} to i8*
>  // CHECK: call void @llvm.memcpy
>
> -  __int128_t u = va_arg (ap, __int128_t);
> -// CHECK: ptrtoint i8* %{{[a-z.0-9]*}} to i64
> -// CHECK: add i64 %{{[0-9]+}}, 15
> -// CHECK: and i64 %{{[0-9]+}}, 4294967280
> -// CHECK: inttoptr i64 %{{[0-9]+}} to i8*
> -
>    int v = va_arg (ap, int);
>  // CHECK: ptrtoint i8* %{{[a-z.0-9]*}} to i64
>  // CHECK: add i64 %{{[0-9]+}}, 4
>
>
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