Merging r370426:

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r370426 | maskray | 2019-08-30 04:20:49 +0200 (Fri, 30 Aug 2019) | 26 lines

[PPC32] Emit R_PPC_GOT_TPREL16 instead R_PPC_GOT_TPREL16_LO

Unlike ppc64, which has ADDISgotTprelHA+LDgotTprelL pairs,
ppc32 just uses LDgotTprelL32, so it does not make lots of sense to use
_LO without a paired _HA.

Emit R_PPC_GOT_TPREL16 instead R_PPC_GOT_TPREL16_LO to match GCC, and
get better linker relocation check. Note, R_PPC_GOT_TPREL16_{HA,LO}
don't have good linker support:

(a) lld does not support R_PPC_GOT_TPREL16_{HA,LO}.
(b) Top of tree ld.bfd does not support R_PPC_GOT_REL16_HA Initial-Exec -> Local-Exec relaxation:

  // a.o
  addis 3, 3, tsd_tls@got@tprel@ha
  lwz 3, tsd_tls@got@tprel@l(3)
  add 3, 3, tsd_tls@tls
  // b.o
  .section .tdata,"awT"; .globl tsd_tls; tsd_tls:

  // ld/ld-new a.o b.o
  internal error, aborting at ../../bfd/elf32-ppc.c:7952 in ppc_elf_relocate_section

Reviewed By: adalava

Differential Revision: https://reviews.llvm.org/D66925
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_90@371059 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCAsmPrinter.cpp b/lib/Target/PowerPC/PPCAsmPrinter.cpp
index bd87ce0..269b84b 100644 (file)
--- a/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -866,8 +866,10 @@ void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
     const GlobalValue *GValue = MO.getGlobal();
     MCSymbol *MOSymbol = getSymbol(GValue);
     const MCExpr *Exp =
-      MCSymbolRefExpr::create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO,
-                              OutContext);
+        MCSymbolRefExpr::create(MOSymbol,
+                                isPPC64 ? MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO
+                                        : MCSymbolRefExpr::VK_PPC_GOT_TPREL,
+                                OutContext);
     TmpInst.getOperand(1) = MCOperand::createExpr(Exp);
     EmitToStreamer(*OutStreamer, TmpInst);
     return;

diff --git a/test/CodeGen/PowerPC/tls.ll b/test/CodeGen/PowerPC/tls.ll
index 6a0ab69..1d6b22e 100644 (file)
--- a/test/CodeGen/PowerPC/tls.ll
+++ b/test/CodeGen/PowerPC/tls.ll
@@ -43,7 +43,7 @@ entry:
 ;OPT0-PPC32-LABEL:    main2:
 ;OPT0-PPC32:       li [[REG1:[0-9]+]], _GLOBAL_OFFSET_TABLE_@l
 ;OPT0-PPC32:       addis [[REG1]], [[REG1]], _GLOBAL_OFFSET_TABLE_@ha
-;OPT0-PPC32:       lwz [[REG2:[0-9]+]], a2@got@tprel@l([[REG1]])
+;OPT0-PPC32:       lwz [[REG2:[0-9]+]], a2@got@tprel([[REG1]])
 ;OPT0-PPC32:       add 3, [[REG2]], a2@tls
 
 ;OPT0-PPC32-PIC-LABEL:  main2:
@@ -51,4 +51,4 @@ entry:
 ;OPT0-PPC32-PIC-NOT:    li {{[0-9]+}}, _GLOBAL_OFFSET_TABLE_@l
 ;OPT0-PPC32-PIC-NOT:    addis {{[0-9]+}}, {{[0-9+]}}, _GLOBAL_OFFSET_TABLE_@ha
 ;OPT0-PPC32-PIC-NOT:    bl __tls_get_addr(a2@tlsgd)@PLT
-;OPT0-PPC32-PIC:        lwz {{[0-9]+}}, a2@got@tprel@l({{[0-9]+}})
+;OPT0-PPC32-PIC:        lwz {{[0-9]+}}, a2@got@tprel({{[0-9]+}})