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[AArch64] Add support for secrel add/load/store relocations for COFF
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Differential Revision: https://reviews.llvm.org/D43288

llvm-svn: 326480
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@mstorsjo
mstorsjo committed Mar 1, 2018
1 parent 36b99e1 commit c61ff3b
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Showing 7 changed files with 69 additions and 4 deletions.
24 changes: 24 additions & 0 deletions llvm/docs/Extensions.rst
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Expand Up @@ -182,6 +182,30 @@ which gnu as does not support. For gas compatibility, sections with a name
starting with ".debug" are implicitly discardable.


ARM64/COFF-Dependent
--------------------

Relocations
^^^^^^^^^^^

The following additional symbol variants are supported:

**:secrel_lo12:** generates a relocation that corresponds to the COFF relocation
types ``IMAGE_REL_ARM64_SECREL_LOW12A`` or ``IMAGE_REL_ARM64_SECREL_LOW12L``.

**:secrel_hi12:** generates a relocation that corresponds to the COFF relocation
type ``IMAGE_REL_ARM64_SECREL_HIGH12A``.

.. code-block:: gas
add x0, x0, :secrel_hi12:symbol
ldr x0, [x0, :secrel_lo12:symbol]
add x1, x1, :secrel_hi12:symbol
add x1, x1, :secrel_lo12:symbol
...
ELF-Dependent
-------------

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14 changes: 11 additions & 3 deletions llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
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Expand Up @@ -518,7 +518,9 @@ class AArch64Operand : public MCParsedAsmOperand {
ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
ELFRefKind == AArch64MCExpr::VK_GOTTPREL_LO12_NC ||
ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12) {
ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12 ||
ELFRefKind == AArch64MCExpr::VK_SECREL_LO12 ||
ELFRefKind == AArch64MCExpr::VK_SECREL_HI12) {
// Note that we don't range-check the addend. It's adjusted modulo page
// size when converted, so there is no "out of range" condition when using
// @pageoff.
Expand Down Expand Up @@ -607,7 +609,9 @@ class AArch64Operand : public MCParsedAsmOperand {
|| ELFRefKind == AArch64MCExpr::VK_TPREL_HI12
|| ELFRefKind == AArch64MCExpr::VK_TPREL_LO12
|| ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC
|| ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12;
|| ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12
|| ELFRefKind == AArch64MCExpr::VK_SECREL_HI12
|| ELFRefKind == AArch64MCExpr::VK_SECREL_LO12;
}

// If it's a constant, it should be a real immediate in range:
Expand Down Expand Up @@ -2854,6 +2858,8 @@ bool AArch64AsmParser::parseSymbolicImmVal(const MCExpr *&ImmVal) {
.Case("gottprel_g1", AArch64MCExpr::VK_GOTTPREL_G1)
.Case("gottprel_g0_nc", AArch64MCExpr::VK_GOTTPREL_G0_NC)
.Case("tlsdesc", AArch64MCExpr::VK_TLSDESC_PAGE)
.Case("secrel_lo12", AArch64MCExpr::VK_SECREL_LO12)
.Case("secrel_hi12", AArch64MCExpr::VK_SECREL_HI12)
.Default(AArch64MCExpr::VK_INVALID);

if (RefKind == AArch64MCExpr::VK_INVALID)
Expand Down Expand Up @@ -3466,7 +3472,9 @@ bool AArch64AsmParser::validateInstruction(MCInst &Inst,
ELFRefKind == AArch64MCExpr::VK_TPREL_HI12 ||
ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12) &&
ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12 ||
ELFRefKind == AArch64MCExpr::VK_SECREL_LO12 ||
ELFRefKind == AArch64MCExpr::VK_SECREL_HI12) &&
(Inst.getOpcode() == AArch64::ADDXri ||
Inst.getOpcode() == AArch64::ADDWri))
return false;
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3 changes: 2 additions & 1 deletion llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp
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Expand Up @@ -276,7 +276,8 @@ AArch64MCCodeEmitter::getAddSubImmOpValue(const MCInst &MI, unsigned OpIdx,
if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
AArch64MCExpr::VariantKind RefKind = A64E->getKind();
if (RefKind == AArch64MCExpr::VK_TPREL_HI12 ||
RefKind == AArch64MCExpr::VK_DTPREL_HI12)
RefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
RefKind == AArch64MCExpr::VK_SECREL_HI12)
ShiftVal = 12;
}
return ShiftVal == 0 ? 0 : (1 << ShiftVal);
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2 changes: 2 additions & 0 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
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Expand Up @@ -70,6 +70,8 @@ StringRef AArch64MCExpr::getVariantKindName() const {
case VK_GOTTPREL_G0_NC: return ":gottprel_g0_nc:";
case VK_TLSDESC: return "";
case VK_TLSDESC_PAGE: return ":tlsdesc:";
case VK_SECREL_LO12: return ":secrel_lo12:";
case VK_SECREL_HI12: return ":secrel_hi12:";
default:
llvm_unreachable("Invalid ELF symbol kind");
}
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3 changes: 3 additions & 0 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
View file
Expand Up @@ -35,6 +35,7 @@ class AArch64MCExpr : public MCTargetExpr {
VK_GOTTPREL = 0x005,
VK_TPREL = 0x006,
VK_TLSDESC = 0x007,
VK_SECREL = 0x008,
VK_SymLocBits = 0x00f,

// Variants specifying which part of the final address calculation is
Expand Down Expand Up @@ -98,6 +99,8 @@ class AArch64MCExpr : public MCTargetExpr {
VK_TPREL_LO12_NC = VK_TPREL | VK_PAGEOFF | VK_NC,
VK_TLSDESC_LO12 = VK_TLSDESC | VK_PAGEOFF,
VK_TLSDESC_PAGE = VK_TLSDESC | VK_PAGE,
VK_SECREL_LO12 = VK_SECREL | VK_PAGEOFF,
VK_SECREL_HI12 = VK_SECREL | VK_HI12,

VK_INVALID = 0xfff
};
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14 changes: 14 additions & 0 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64WinCOFFObjectWriter.cpp
View file
Expand Up @@ -8,6 +8,7 @@
//===---------------------------------------------------------------------===//

#include "MCTargetDesc/AArch64FixupKinds.h"
#include "MCTargetDesc/AArch64MCExpr.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/MC/MCAsmBackend.h"
Expand Down Expand Up @@ -46,6 +47,7 @@ unsigned AArch64WinCOFFObjectWriter::getRelocType(
bool IsCrossSection, const MCAsmBackend &MAB) const {
auto Modifier = Target.isAbsolute() ? MCSymbolRefExpr::VK_None
: Target.getSymA()->getKind();
const MCExpr *Expr = Fixup.getValue();

switch (static_cast<unsigned>(Fixup.getKind())) {
default: {
Expand Down Expand Up @@ -73,13 +75,25 @@ unsigned AArch64WinCOFFObjectWriter::getRelocType(
return COFF::IMAGE_REL_ARM64_SECREL;

case AArch64::fixup_aarch64_add_imm12:
if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
AArch64MCExpr::VariantKind RefKind = A64E->getKind();
if (RefKind == AArch64MCExpr::VK_SECREL_LO12)
return COFF::IMAGE_REL_ARM64_SECREL_LOW12A;
if (RefKind == AArch64MCExpr::VK_SECREL_HI12)
return COFF::IMAGE_REL_ARM64_SECREL_HIGH12A;
}
return COFF::IMAGE_REL_ARM64_PAGEOFFSET_12A;

case AArch64::fixup_aarch64_ldst_imm12_scale1:
case AArch64::fixup_aarch64_ldst_imm12_scale2:
case AArch64::fixup_aarch64_ldst_imm12_scale4:
case AArch64::fixup_aarch64_ldst_imm12_scale8:
case AArch64::fixup_aarch64_ldst_imm12_scale16:
if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
AArch64MCExpr::VariantKind RefKind = A64E->getKind();
if (RefKind == AArch64MCExpr::VK_SECREL_LO12)
return COFF::IMAGE_REL_ARM64_SECREL_LOW12L;
}
return COFF::IMAGE_REL_ARM64_PAGEOFFSET_12L;

case AArch64::fixup_aarch64_pcrel_adrp_imm21:
Expand Down
13 changes: 13 additions & 0 deletions llvm/test/MC/AArch64/coff-relocations.s
View file
Expand Up @@ -45,6 +45,13 @@ add x0, x0, :lo12:foo + 0x12345
ldrb w0, [x0, :lo12:foo + 0x12345]
ldr x0, [x0, :lo12:foo + 0x12348]

; IMAGE_REL_ARM64_SECREL_LOW12A
add x0, x0, :secrel_lo12:foo
; IMAGE_REL_ARM64_SECREL_HIGH12A
add x0, x0, :secrel_hi12:foo
; IMAGE_REL_ARM64_SECREL_LOW12L
ldr x0, [x0, :secrel_lo12:foo]

; CHECK: Format: COFF-ARM64
; CHECK: Arch: aarch64
; CHECK: AddressSize: 64bit
Expand All @@ -64,10 +71,16 @@ ldr x0, [x0, :lo12:foo + 0x12348]
; CHECK: 0x34 IMAGE_REL_ARM64_PAGEOFFSET_12A foo
; CHECK: 0x38 IMAGE_REL_ARM64_PAGEOFFSET_12L foo
; CHECK: 0x3C IMAGE_REL_ARM64_PAGEOFFSET_12L foo
; CHECK: 0x40 IMAGE_REL_ARM64_SECREL_LOW12A foo
; CHECK: 0x44 IMAGE_REL_ARM64_SECREL_HIGH12A foo
; CHECK: 0x48 IMAGE_REL_ARM64_SECREL_LOW12L foo
; CHECK: }
; CHECK: ]

; DISASM: 30: 20 1a 09 b0 adrp x0, #305418240
; DISASM: 34: 00 14 0d 91 add x0, x0, #837
; DISASM: 38: 00 14 4d 39 ldrb w0, [x0, #837]
; DISASM: 3c: 00 a4 41 f9 ldr x0, [x0, #840]
; DISASM: 40: 00 00 00 91 add x0, x0, #0
; DISASM: 44: 00 00 40 91 add x0, x0, #0, lsl #12
; DISASM: 48: 00 00 40 f9 ldr x0, [x0]

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