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

[Davide Italiano via llvm-commits]

On Wed, Sep 28, 2016 at 6:59 PM, Davide Italiano <davide at freebsd.org> wrote:
> 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?
>

http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/21667

-- 
Davide

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