[llvm] r185945 - [PowerPC] Revert r185476 and fix up TLS variant kinds
Ulrich Weigand
ulrich.weigand at de.ibm.com
Tue Jul 9 09:41:10 PDT 2013
Author: uweigand
Date: Tue Jul 9 11:41:09 2013
New Revision: 185945
URL: http://llvm.org/viewvc/llvm-project?rev=185945&view=rev
Log:
[PowerPC] Revert r185476 and fix up TLS variant kinds
In the commit message to r185476 I wrote:
>The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
>correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
>This causes some confusion with the asm parser, since VK_PPC_TLSGD
>is output as @tlsgd, which is then read back in as VK_TLSGD.
>
>To avoid this confusion, this patch removes the PowerPC-specific
>modifiers and uses the generic modifiers throughout. (The only
>drawback is that the generic modifiers are printed in upper case
>while the usual convention on PowerPC is to use lower-case modifiers.
>But this is just a cosmetic issue.)
This was unfortunately incorrect, there is is fact another,
serious drawback to using the default VK_TLSLD/VK_TLSGD
variant kinds: using these causes ELFObjectWriter::RelocNeedsGOT
to return true, which in turn causes the ELFObjectWriter to emit
an undefined reference to _GLOBAL_OFFSET_TABLE_.
This is a problem on powerpc64, because it uses the TOC instead
of the GOT, and the linker does not provide _GLOBAL_OFFSET_TABLE_,
so the symbol remains undefined. This means shared libraries
using TLS built with the integrated assembler are currently
broken.
While the whole RelocNeedsGOT / _GLOBAL_OFFSET_TABLE_ situation
probably ought to be properly fixed at some point, for now I'm
simply reverting the r185476 commit. Now this in turn exposes
the breakage of handling @tlsgd/@tlsld in the asm parser that
this check-in was originally intended to fix.
To avoid this regression, I'm also adding a different fix for
this problem: while common code now parses @tlsgd as VK_TLSGD,
a special hack in the asm parser translates this code to the
platform-specific VK_PPC_TLSGD that the back-end now expects.
While this is not really pretty, it's self-contained and
shouldn't hurt anything else for now. One the underlying
problem is fixed, this hack can be reverted again.
Modified:
llvm/trunk/include/llvm/MC/MCExpr.h
llvm/trunk/lib/MC/MCELFStreamer.cpp
llvm/trunk/lib/MC/MCExpr.cpp
llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
llvm/trunk/test/CodeGen/PowerPC/tls-gd.ll
llvm/trunk/test/CodeGen/PowerPC/tls-ld-2.ll
llvm/trunk/test/CodeGen/PowerPC/tls-ld.ll
llvm/trunk/test/MC/PowerPC/ppc64-fixups.s
Modified: llvm/trunk/include/llvm/MC/MCExpr.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCExpr.h?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCExpr.h (original)
+++ llvm/trunk/include/llvm/MC/MCExpr.h Tue Jul 9 11:41:09 2013
@@ -216,10 +216,12 @@ public:
VK_PPC_GOT_TLSGD_LO, // symbol at got@tlsgd at l
VK_PPC_GOT_TLSGD_HI, // symbol at got@tlsgd at h
VK_PPC_GOT_TLSGD_HA, // symbol at got@tlsgd at ha
+ VK_PPC_TLSGD, // symbol at tlsgd
VK_PPC_GOT_TLSLD, // symbol at got@tlsld
VK_PPC_GOT_TLSLD_LO, // symbol at got@tlsld at l
VK_PPC_GOT_TLSLD_HI, // symbol at got@tlsld at h
VK_PPC_GOT_TLSLD_HA, // symbol at got@tlsld at ha
+ VK_PPC_TLSLD, // symbol at tlsld
VK_Mips_GPREL,
VK_Mips_GOT_CALL,
Modified: llvm/trunk/lib/MC/MCELFStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCELFStreamer.cpp?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCELFStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCELFStreamer.cpp Tue Jul 9 11:41:09 2013
@@ -392,10 +392,12 @@ void MCELFStreamer::fixSymbolsInTLSFixu
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO:
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI:
case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA:
+ case MCSymbolRefExpr::VK_PPC_TLSGD:
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD:
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO:
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI:
case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA:
+ case MCSymbolRefExpr::VK_PPC_TLSLD:
break;
}
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(symRef.getSymbol());
Modified: llvm/trunk/lib/MC/MCExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCExpr.cpp?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCExpr.cpp (original)
+++ llvm/trunk/lib/MC/MCExpr.cpp Tue Jul 9 11:41:09 2013
@@ -241,10 +241,12 @@ StringRef MCSymbolRefExpr::getVariantKin
case VK_PPC_GOT_TLSGD_LO: return "got at tlsgd@l";
case VK_PPC_GOT_TLSGD_HI: return "got at tlsgd@h";
case VK_PPC_GOT_TLSGD_HA: return "got at tlsgd@ha";
+ case VK_PPC_TLSGD: return "tlsgd";
case VK_PPC_GOT_TLSLD: return "got at tlsld";
case VK_PPC_GOT_TLSLD_LO: return "got at tlsld@l";
case VK_PPC_GOT_TLSLD_HI: return "got at tlsld@h";
case VK_PPC_GOT_TLSLD_HA: return "got at tlsld@ha";
+ case VK_PPC_TLSLD: return "tlsld";
case VK_Mips_GPREL: return "GPREL";
case VK_Mips_GOT_CALL: return "GOT_CALL";
case VK_Mips_GOT16: return "GOT16";
Modified: llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp Tue Jul 9 11:41:09 2013
@@ -190,6 +190,7 @@ class PPCAsmParser : public MCTargetAsmP
const MCExpr *ExtractModifierFromExpr(const MCExpr *E,
PPCMCExpr::VariantKind &Variant);
+ const MCExpr *FixupVariantKind(const MCExpr *E);
bool ParseExpression(const MCExpr *&EVal);
bool ParseOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands);
@@ -1006,6 +1007,57 @@ ExtractModifierFromExpr(const MCExpr *E,
llvm_unreachable("Invalid expression kind!");
}
+/// Find all VK_TLSGD/VK_TLSLD symbol references in expression and replace
+/// them by VK_PPC_TLSGD/VK_PPC_TLSLD. This is necessary to avoid having
+/// _GLOBAL_OFFSET_TABLE_ created via ELFObjectWriter::RelocNeedsGOT.
+/// FIXME: This is a hack.
+const MCExpr *PPCAsmParser::
+FixupVariantKind(const MCExpr *E) {
+ MCContext &Context = getParser().getContext();
+
+ switch (E->getKind()) {
+ case MCExpr::Target:
+ case MCExpr::Constant:
+ return E;
+
+ case MCExpr::SymbolRef: {
+ const MCSymbolRefExpr *SRE = cast<MCSymbolRefExpr>(E);
+ MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+
+ switch (SRE->getKind()) {
+ case MCSymbolRefExpr::VK_TLSGD:
+ Variant = MCSymbolRefExpr::VK_PPC_TLSGD;
+ break;
+ case MCSymbolRefExpr::VK_TLSLD:
+ Variant = MCSymbolRefExpr::VK_PPC_TLSLD;
+ break;
+ default:
+ return E;
+ }
+ return MCSymbolRefExpr::Create(&SRE->getSymbol(), Variant, Context);
+ }
+
+ case MCExpr::Unary: {
+ const MCUnaryExpr *UE = cast<MCUnaryExpr>(E);
+ const MCExpr *Sub = FixupVariantKind(UE->getSubExpr());
+ if (Sub == UE->getSubExpr())
+ return E;
+ return MCUnaryExpr::Create(UE->getOpcode(), Sub, Context);
+ }
+
+ case MCExpr::Binary: {
+ const MCBinaryExpr *BE = cast<MCBinaryExpr>(E);
+ const MCExpr *LHS = FixupVariantKind(BE->getLHS());
+ const MCExpr *RHS = FixupVariantKind(BE->getRHS());
+ if (LHS == BE->getLHS() && RHS == BE->getRHS())
+ return E;
+ return MCBinaryExpr::Create(BE->getOpcode(), LHS, RHS, Context);
+ }
+ }
+
+ llvm_unreachable("Invalid expression kind!");
+}
+
/// Parse an expression. This differs from the default "parseExpression"
/// in that it handles complex \code @l/@ha \endcode modifiers.
bool PPCAsmParser::
@@ -1013,6 +1065,8 @@ ParseExpression(const MCExpr *&EVal) {
if (getParser().parseExpression(EVal))
return true;
+ EVal = FixupVariantKind(EVal);
+
PPCMCExpr::VariantKind Variant;
const MCExpr *E = ExtractModifierFromExpr(EVal, Variant);
if (E)
Modified: llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp Tue Jul 9 11:41:09 2013
@@ -312,10 +312,10 @@ unsigned PPCELFObjectWriter::getRelocTyp
case PPC::fixup_ppc_nofixup:
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
- case MCSymbolRefExpr::VK_TLSGD:
+ case MCSymbolRefExpr::VK_PPC_TLSGD:
Type = ELF::R_PPC64_TLSGD;
break;
- case MCSymbolRefExpr::VK_TLSLD:
+ case MCSymbolRefExpr::VK_PPC_TLSLD:
Type = ELF::R_PPC64_TLSLD;
break;
case MCSymbolRefExpr::VK_PPC_TLS:
Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Tue Jul 9 11:41:09 2013
@@ -573,7 +573,8 @@ void PPCAsmPrinter::EmitInstruction(cons
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = Mang->getSymbol(GValue);
const MCExpr *SymVar =
- MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_TLSGD, OutContext);
+ MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TLSGD,
+ OutContext);
OutStreamer.EmitInstruction(MCInstBuilder(PPC::BL8_NOP_TLS)
.addExpr(TlsRef)
.addExpr(SymVar));
@@ -624,7 +625,8 @@ void PPCAsmPrinter::EmitInstruction(cons
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = Mang->getSymbol(GValue);
const MCExpr *SymVar =
- MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_TLSLD, OutContext);
+ MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TLSLD,
+ OutContext);
OutStreamer.EmitInstruction(MCInstBuilder(PPC::BL8_NOP_TLS)
.addExpr(TlsRef)
.addExpr(SymVar));
Modified: llvm/trunk/test/CodeGen/PowerPC/tls-gd.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/tls-gd.ll?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/tls-gd.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/tls-gd.ll Tue Jul 9 11:41:09 2013
@@ -18,6 +18,6 @@ entry:
; CHECK: addis [[REG:[0-9]+]], 2, a at got@tlsgd at ha
; CHECK-NEXT: addi 3, [[REG]], a at got@tlsgd at l
-; CHECK: bl __tls_get_addr(a at TLSGD)
+; CHECK: bl __tls_get_addr(a at tlsgd)
; CHECK-NEXT: nop
Modified: llvm/trunk/test/CodeGen/PowerPC/tls-ld-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/tls-ld-2.ll?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/tls-ld-2.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/tls-ld-2.ll Tue Jul 9 11:41:09 2013
@@ -18,7 +18,7 @@ entry:
; CHECK: addis [[REG:[0-9]+]], 2, a at got@tlsld at ha
; CHECK-NEXT: addi 3, [[REG]], a at got@tlsld at l
-; CHECK: bl __tls_get_addr(a at TLSLD)
+; CHECK: bl __tls_get_addr(a at tlsld)
; CHECK-NEXT: nop
; CHECK: addis [[REG2:[0-9]+]], 3, a at dtprel@ha
; CHECK-NEXT: lwa {{[0-9]+}}, a at dtprel@l([[REG2]])
Modified: llvm/trunk/test/CodeGen/PowerPC/tls-ld.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/tls-ld.ll?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/tls-ld.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/tls-ld.ll Tue Jul 9 11:41:09 2013
@@ -18,7 +18,7 @@ entry:
; CHECK: addis [[REG:[0-9]+]], 2, a at got@tlsld at ha
; CHECK-NEXT: addi 3, [[REG]], a at got@tlsld at l
-; CHECK: bl __tls_get_addr(a at TLSLD)
+; CHECK: bl __tls_get_addr(a at tlsld)
; CHECK-NEXT: nop
; CHECK: addis [[REG2:[0-9]+]], 3, a at dtprel@ha
; CHECK-NEXT: addi {{[0-9]+}}, [[REG2]], a at dtprel@l
Modified: llvm/trunk/test/MC/PowerPC/ppc64-fixups.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/PowerPC/ppc64-fixups.s?rev=185945&r1=185944&r2=185945&view=diff
==============================================================================
--- llvm/trunk/test/MC/PowerPC/ppc64-fixups.s (original)
+++ llvm/trunk/test/MC/PowerPC/ppc64-fixups.s Tue Jul 9 11:41:09 2013
@@ -404,15 +404,15 @@ base:
# CHECK-REL: 0x{{[0-9A-F]*[26AE]}} R_PPC64_GOT_TLSLD16 target 0x0
addi 3, 3, target at got@tlsld
-# CHECK: bl __tls_get_addr(target at TLSGD) # encoding: [0b010010BB,B,B,0bBBBBBB01]
-# CHECK-NEXT: # fixup A - offset: 0, value: target at TLSGD, kind: fixup_ppc_nofixup
+# CHECK: bl __tls_get_addr(target at tlsgd) # encoding: [0b010010BB,B,B,0bBBBBBB01]
+# CHECK-NEXT: # fixup A - offset: 0, value: target at tlsgd, kind: fixup_ppc_nofixup
# CHECK-NEXT: # fixup B - offset: 0, value: __tls_get_addr, kind: fixup_ppc_br24
# CHECK-REL: 0x{{[0-9A-F]*[048C]}} R_PPC64_TLSGD target 0x0
# CHECK-REL-NEXT: 0x{{[0-9A-F]*[048C]}} R_PPC64_REL24 __tls_get_addr 0x0
bl __tls_get_addr(target at tlsgd)
-# CHECK: bl __tls_get_addr(target at TLSLD) # encoding: [0b010010BB,B,B,0bBBBBBB01]
-# CHECK-NEXT: # fixup A - offset: 0, value: target at TLSLD, kind: fixup_ppc_nofixup
+# CHECK: bl __tls_get_addr(target at tlsld) # encoding: [0b010010BB,B,B,0bBBBBBB01]
+# CHECK-NEXT: # fixup A - offset: 0, value: target at tlsld, kind: fixup_ppc_nofixup
# CHECK-NEXT: # fixup B - offset: 0, value: __tls_get_addr, kind: fixup_ppc_br24
# CHECK-REL: 0x{{[0-9A-F]*[048C]}} R_PPC64_TLSLD target 0x0
# CHECK-REL-NEXT: 0x{{[0-9A-F]*[048C]}} R_PPC64_REL24 __tls_get_addr 0x0
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