[AArch64] [COFF] Move jump tables back to the readonly section

This essentially reverts f5884d255e78305d41c28c6e001a460ff83981d8
(D57277).

That commit was made as a workaround since LLVM back then didn't
support cross-section relative relocations (IMAGE_REL_ARM64_REL32)
in COFF for ARM64. Support for this was implemented later,
in d5c5cf5ce8d921fc8c5e1b608c298a1ffa688d37 (D99572) and
382c505d9cfca8adaec47aea2da7bbcbc00fc05c (D102217).

The commit that moved jump tables to the function section noted
that it woud be ideal to utilize IMAGE_REL_ARM64_REL32.

Differential Revision: https://reviews.llvm.org/D113576

diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 9f527a1..aeebb49 100644 (file)
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -818,18 +818,9 @@ void AArch64AsmPrinter::emitJumpTableInfo() {
   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
   if (JT.empty()) return;
 
-  const Function &F = MF->getFunction();
   const TargetLoweringObjectFile &TLOF = getObjFileLowering();
-  bool JTInDiffSection =
-      !STI->isTargetCOFF() ||
-      !TLOF.shouldPutJumpTableInFunctionSection(
-          MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
-          F);
-  if (JTInDiffSection) {
-      // Drop it in the readonly section.
-      MCSection *ReadOnlySec = TLOF.getSectionForJumpTable(F, TM);
-      OutStreamer->SwitchSection(ReadOnlySec);
-  }
+  MCSection *ReadOnlySec = TLOF.getSectionForJumpTable(MF->getFunction(), TM);
+  OutStreamer->SwitchSection(ReadOnlySec);
 
   auto AFI = MF->getInfo<AArch64FunctionInfo>();
   for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {

diff --git a/llvm/test/CodeGen/AArch64/win64-jumptable.ll b/llvm/test/CodeGen/AArch64/win64-jumptable.ll
index 4c19ee8..5de4d79 100644 (file)
--- a/llvm/test/CodeGen/AArch64/win64-jumptable.ll
+++ b/llvm/test/CodeGen/AArch64/win64-jumptable.ll
@@ -38,12 +38,14 @@ declare void @g(i32, i32)
 ; CHECK:    .seh_proc f
 ; CHECK:    b g
 ; CHECK-NEXT:  .seh_endfunclet
+; CHECK-NEXT:  .section .rdata,"dr"
 ; CHECK-NEXT: .p2align  2
 ; CHECK-NEXT: .LJTI0_0:
 ; CHECK:    .word .LBB0_2-.Ltmp0
 ; CHECK:    .word .LBB0_3-.Ltmp0
 ; CHECK:    .word .LBB0_4-.Ltmp0
 ; CHECK:    .word .LBB0_5-.Ltmp0
+; CHECK:    .text
 ; CHECK:    .seh_endproc
 
 ; Check that we can emit an object file with correct unwind info.