[llvm] r282661 - AArch64: Set shift bit of TLSLE HI12 add instruction

[Davide Italiano via llvm-commits]

On Wed, Sep 28, 2016 at 6:05 PM, Lei Liu via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: lliu0
> Date: Wed Sep 28 20:05:48 2016
> New Revision: 282661
>
> URL: http://llvm.org/viewvc/llvm-project?rev=282661&view=rev
> Log:
> AArch64: Set shift bit of TLSLE HI12 add instruction
>
> Summary: AArch64 LLVM assembler emits add instruction without shift bit to calculate the higher 12-bit address of TLS variables in local exec model.  This generates wrong code sequence to access TLS variables with thread offset larger than 0x1000.
>
> Reviewers: t.p.northover, peter.smith, rovka
>
> Subscribers: salim.nasser, aemerson, llvm-commits, rengolin
>
> Differential Revision: https://reviews.llvm.org/D24702
>
> Added:
>     llvm/trunk/test/MC/AArch64/tls-add-shift.s
> Modified:
>     llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp
>
> Modified: llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp?rev=282661&r1=282660&r2=282661&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp (original)
> +++ llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp Wed Sep 28 20:05:48 2016
> @@ -263,6 +263,14 @@ AArch64MCCodeEmitter::getAddSubImmOpValu
>
>    ++MCNumFixups;
>
> +  // Set the shift bit of the add instruction for relocation types
> +  // R_AARCH64_TLSLE_ADD_TPREL_HI12 and R_AARCH64_TLSLD_ADD_DTPREL_HI12.
> +  if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
> +    AArch64MCExpr::VariantKind RefKind = A64E->getKind();
> +    if (RefKind == AArch64MCExpr::VK_TPREL_HI12 ||
> +        RefKind == AArch64MCExpr::VK_DTPREL_HI12)
> +      ShiftVal = 12;
> +  }
>    return ShiftVal == 0 ? 0 : (1 << ShiftVal);
>  }
>
>
> Added: llvm/trunk/test/MC/AArch64/tls-add-shift.s
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/tls-add-shift.s?rev=282661&view=auto
> ==============================================================================
> --- llvm/trunk/test/MC/AArch64/tls-add-shift.s (added)
> +++ llvm/trunk/test/MC/AArch64/tls-add-shift.s Wed Sep 28 20:05:48 2016
> @@ -0,0 +1,12 @@
> +// RUN: llvm-mc -triple=aarch64-none-linux-gnu -filetype=obj < %s -o - | \
> +// RUN:   llvm-objdump -r -d - | FileCheck %s
> +
> +  // TLS add TPREL
> +  add x2, x1, #:tprel_hi12:var
> +// CHECK: add x2, x1, #0, lsl #12
> +// CHECK-NEXT: R_AARCH64_TLSLE_ADD_TPREL_HI12 var
> +
> +  // TLS add DTPREL
> +  add x4, x3, #:dtprel_hi12:var
> +// CHECK: add x4, x3, #0, lsl #12
> +// CHECK-NEXT: R_AARCH64_TLSLD_ADD_DTPREL_HI12 var
>
>
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Hi Lei,
unfortunately this commit broke an lld test. Can you please check if
it's easy to fix for you or revert otherwise?

Thanks!

-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare