[llvm] r200446 - ARM: support tlscall relocations
Saleem Abdulrasool
compnerd at compnerd.org
Wed Jan 29 20:02:31 PST 2014
Author: compnerd
Date: Wed Jan 29 22:02:31 2014
New Revision: 200446
URL: http://llvm.org/viewvc/llvm-project?rev=200446&view=rev
Log:
ARM: support tlscall relocations
This adds support for TLS CALL relocations. TLS CALL relocations are used to
indicate to the linker to generate appropriate entries to resolve TLS references
via an appropriate function invocation (e.g. __tls_get_addr(PLT)).
In order to accomodate the linker relaxation of the TLS access model for the
references (GD/LD -> IE, IE -> LE), the relocation addend must be incomplete.
This requires that the partial inplace value is also incomplete (i.e. 0). We
simply avoid the offset value calculation at the time of the fixup adjustment in
the ARM assembler backend.
Modified:
llvm/trunk/include/llvm/MC/MCExpr.h
llvm/trunk/lib/MC/MCExpr.cpp
llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
llvm/trunk/test/MC/ARM/symbol-variants.s
Modified: llvm/trunk/include/llvm/MC/MCExpr.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCExpr.h?rev=200446&r1=200445&r2=200446&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCExpr.h (original)
+++ llvm/trunk/include/llvm/MC/MCExpr.h Wed Jan 29 22:02:31 2014
@@ -166,6 +166,7 @@ public:
VK_ARM_TARGET2,
VK_ARM_PREL31,
VK_ARM_TLSLDO, // symbol(tlsldo)
+ VK_ARM_TLSCALL, // symbol(tlscall)
VK_PPC_LO, // symbol at l
VK_PPC_HI, // symbol at h
Modified: llvm/trunk/lib/MC/MCExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCExpr.cpp?rev=200446&r1=200445&r2=200446&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCExpr.cpp (original)
+++ llvm/trunk/lib/MC/MCExpr.cpp Wed Jan 29 22:02:31 2014
@@ -185,6 +185,7 @@ StringRef MCSymbolRefExpr::getVariantKin
case VK_ARM_TARGET2: return "target2";
case VK_ARM_PREL31: return "prel31";
case VK_ARM_TLSLDO: return "tlsldo";
+ case VK_ARM_TLSCALL: return "tlscall";
case VK_PPC_LO: return "l";
case VK_PPC_HI: return "h";
case VK_PPC_HA: return "ha";
@@ -408,6 +409,8 @@ MCSymbolRefExpr::getVariantKindForName(S
.Case("prel31", VK_ARM_PREL31)
.Case("TLSLDO", VK_ARM_TLSLDO)
.Case("tlsldo", VK_ARM_TLSLDO)
+ .Case("TLSCALL", VK_ARM_TLSCALL)
+ .Case("tlscall", VK_ARM_TLSCALL)
.Default(VK_Invalid);
}
Modified: llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp?rev=200446&r1=200445&r2=200446&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp Wed Jan 29 22:02:31 2014
@@ -380,6 +380,9 @@ static unsigned adjustFixupValue(const M
case ARM::fixup_arm_blx:
// These values don't encode the low two bits since they're always zero.
// Offset by 8 just as above.
+ if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
+ if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_TLSCALL)
+ return 0;
return 0xffffff & ((Value - 8) >> 2);
case ARM::fixup_t2_uncondbranch: {
Value = Value - 4;
@@ -461,6 +464,9 @@ static unsigned adjustFixupValue(const M
// Note that the halfwords are stored high first, low second; so we need
// to transpose the fixup value here to map properly.
uint32_t offset = (Value - 2) >> 2;
+ if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
+ if (SRE->getKind() == MCSymbolRefExpr::VK_ARM_TLSCALL)
+ offset = 0;
uint32_t signBit = (offset & 0x400000) >> 22;
uint32_t I1Bit = (offset & 0x200000) >> 21;
uint32_t J1Bit = (I1Bit ^ 0x1) ^ signBit;
Modified: llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp?rev=200446&r1=200445&r2=200446&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp Wed Jan 29 22:02:31 2014
@@ -179,6 +179,9 @@ unsigned ARMELFObjectWriter::GetRelocTyp
case MCSymbolRefExpr::VK_PLT:
Type = ELF::R_ARM_PLT32;
break;
+ case MCSymbolRefExpr::VK_ARM_TLSCALL:
+ Type = ELF::R_ARM_TLS_CALL;
+ break;
default:
Type = ELF::R_ARM_CALL;
break;
@@ -211,7 +214,14 @@ unsigned ARMELFObjectWriter::GetRelocTyp
break;
case ARM::fixup_arm_thumb_bl:
case ARM::fixup_arm_thumb_blx:
- Type = ELF::R_ARM_THM_CALL;
+ switch (Modifier) {
+ case MCSymbolRefExpr::VK_ARM_TLSCALL:
+ Type = ELF::R_ARM_THM_TLS_CALL;
+ break;
+ default:
+ Type = ELF::R_ARM_THM_CALL;
+ break;
+ }
break;
}
} else {
@@ -253,6 +263,9 @@ unsigned ARMELFObjectWriter::GetRelocTyp
case MCSymbolRefExpr::VK_ARM_TLSLDO:
Type = ELF::R_ARM_TLS_LDO32;
break;
+ case MCSymbolRefExpr::VK_ARM_TLSCALL:
+ Type = ELF::R_ARM_TLS_CALL;
+ break;
}
break;
case ARM::fixup_arm_ldst_pcrel_12:
Modified: llvm/trunk/test/MC/ARM/symbol-variants.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/symbol-variants.s?rev=200446&r1=200445&r2=200446&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/symbol-variants.s (original)
+++ llvm/trunk/test/MC/ARM/symbol-variants.s Wed Jan 29 22:02:31 2014
@@ -70,3 +70,10 @@ bl f05(plt)
.word f21(tlsldo)
@CHECK: 80 R_ARM_TLS_LDO32 f20
@CHECK: 84 R_ARM_TLS_LDO32 f21
+
+@ tlscall
+.word f22(TLSCALL)
+.word f23(tlscall)
+@ CHECK: 88 R_ARM_TLS_CALL f22
+@ CHECK: 92 R_ARM_TLS_CALL f23
+
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