[Hexagon] Add Extended GD_PLT relocations

[sidneym]

Summary

Extended versions of GD_PLT_B22_PCREL. These surface when -mlong-calls option is used.

[MaskRay]

lld/test/ELF/hexagon-tls-gd-nonpreemptible.s

6

s/-check-prefix/--check-prefix/

21

R_ is misaligned

[sidneym]

Address comments, --check-prefix, alignment of checks.

[MaskRay]

Thanks!

lld/ELF/Arch/Hexagon.cpp

case R_HEX_32_PCREL:
     return R_PC;
   case R_HEX_B9_PCREL_X:
   case R_HEX_B15_PCREL_X:
   case R_HEX_B22_PCREL:
   case R_HEX_PLT_B22_PCREL:
   case R_HEX_B22_PCREL_X:
   case R_HEX_B32_PCREL_X:
   case R_HEX_GD_PLT_B22_PCREL:
+  case R_HEX_GD_PLT_B22_PCREL_X:
+  case R_HEX_GD_PLT_B32_PCREL_X:
     return R_PLT_PC;
   case R_HEX_IE_32_6_X:
   case R_HEX_IE_16_X:
   case R_HEX_IE_HI16:
   case R_HEX_IE_LO16:
     return R_GOT;
   case R_HEX_GD_GOT_11_X:
   case R_HEX_GD_GOT_16_X:
case R_HEX_B13_PCREL:
     break;
   case R_HEX_B15_PCREL:
     checkInt(loc, val, 17, rel);
     or32le(loc, applyMask(0x00df20fe, val >> 2));
     break;
   case R_HEX_B15_PCREL_X:
     or32le(loc, applyMask(0x00df20fe, val & 0x3f));
     break;
-  case R_HEX_GD_PLT_B22_PCREL:
   case R_HEX_B22_PCREL:
+  case R_HEX_GD_PLT_B22_PCREL:
   case R_HEX_PLT_B22_PCREL:
     checkInt(loc, val, 22, rel);
     or32le(loc, applyMask(0x1ff3ffe, val >> 2));
     break;
   case R_HEX_B22_PCREL_X:
+  case R_HEX_GD_PLT_B22_PCREL_X:
     or32le(loc, applyMask(0x1ff3ffe, val & 0x3f));
     break;
   case R_HEX_B32_PCREL_X:
+  case R_HEX_GD_PLT_B32_PCREL_X:
     or32le(loc, applyMask(0x0fff3fff, val >> 6));
     break;
   case R_HEX_GOTREL_HI16:
   case R_HEX_HI16:
   case R_HEX_IE_GOT_HI16:
   case R_HEX_IE_HI16:
   case R_HEX_TPREL_HI16:
     or32le(loc, applyMask(0x00c03fff, val >> 16));

lld/ELF/Relocations.cpp

if (expr == R_GOT_PC && !isAbsoluteValue(sym)) {
       expr = target->adjustRelaxExpr(type, relocatedAddr, expr);
     } else {
       // The 0x8000 bit of r_addend of R_PPC_PLTREL24 is used to choose call
       // stub type. It should be ignored if optimized to R_PC.
       if (config->emachine == EM_PPC && expr == R_PPC32_PLTREL)
         addend &= ~0x8000;
       // R_HEX_GD_PLT_B22_PCREL (call a@GDPLT) is transformed into
       // call __tls_get_addr even if the symbol is non-preemptible.
-      if (!(config->emachine == EM_HEXAGON && type == R_HEX_GD_PLT_B22_PCREL))
-        expr = fromPlt(expr);
+      if (!(config->emachine == EM_HEXAGON &&
+           (type == R_HEX_GD_PLT_B22_PCREL ||
+            type == R_HEX_GD_PLT_B22_PCREL_X ||
+            type == R_HEX_GD_PLT_B32_PCREL_X)))
     }
   }
 
   // If the relocation does not emit a GOT or GOTPLT entry but its computation
   // uses their addresses, we need GOT or GOTPLT to be created.
   //
   // The 4 types that relative GOTPLT are all x86 and x86-64 specific.
   if (oneof<R_GOTPLTONLY_PC, R_GOTPLTREL, R_GOTPLT, R_TLSGD_GOTPLT>(expr)) {

lld/test/ELF/hexagon-tls-gd-nonpreemptible.s

 
 # REQUIRES: hexagon
 # RUN: llvm-mc -filetype=obj -triple=hexagon-unknown-elf %s -o %t.o
 # RUN: ld.lld -shared %t.o -o %t.so
 # RUN: llvm-readobj -r %t.so | FileCheck --check-prefix=RELOC %s
+# RUN: llvm-readobj -r %t.o | FileCheck --check-prefix=REL %s
 # RUN: llvm-objdump -d --no-show-raw-insn --print-imm-hex %t.so | FileCheck %s
 
 ## Prior to D77021 lld would error "relocation R_HEX_GD_PLT_B22_PCREL cannot refer to absolute symbol".
 ## A PC-relative relocation referencing a non-preemptible absolute symbol (due to STT_TLS) is not representable in -pie/-shared mode.
 ## For this case we will actually patch the symbol to the external __tls_get_addr which is preemptible.
 
 .globl _start
 .type _start, @function
 
 # RELOC:      Section ({{.*}}) .rela.plt {
 # RELOC-NEXT:   R_HEX_JMP_SLOT - 0x0
 # RELOC-NEXT:   R_HEX_JMP_SLOT __tls_get_addr 0x0
 # RELOC-NEXT: }
 
+# REL:      R_HEX_B32_PCREL_X _GLOBAL_OFFSET_TABLE_ 0x0
+# REL-NEXT: R_HEX_6_PCREL_X _GLOBAL_OFFSET_TABLE_ 0x4
+# REL-NEXT: R_HEX_GD_GOT_32_6_X a 0x0
+# REL-NEXT: R_HEX_GD_GOT_16_X a 0x0
+# REL-NEXT: R_HEX_GD_PLT_B22_PCREL a 0x0
+# REL-NEXT: R_HEX_GD_PLT_B32_PCREL_X a 0x0
+# REL-NEXT: R_HEX_GD_PLT_B22_PCREL_X a 0x4
+
 # CHECK:      { immext(#{{.*}})
 # CHECK-NEXT:   r2 = add(pc,##{{.*}}) }
 # CHECK-NEXT: { immext(#{{.*}})
 # CHECK-NEXT:   r0 = add(r2,##-{{.*}}) }
 # CHECK-NEXT: { call {{.*}} }
+# CHECK-NEXT: { immext({{.*}})
+# CHECK-NEXT:   call {{.*}} }
 # CHECK-NEXT: { r0 = memw(r0+#0x0) }
 
 _start:
   r2 = add(pc,##_GLOBAL_OFFSET_TABLE_@PCREL)
   r0 = add(r2,##a@GDGOT)
   call a@GDPLT
+  call ##a@GDPLT
   r0 = memw(r0+#0)
 
 ## a is non-preemptible due to STV_HIDDEN visibility.
 ## We can achieve the same effect with -Bsymbolic.
 .section        .tdata,"awT",@progbits
 .globl  a
 .hidden a
 a:
 .word 1