[Thumb] Fix invalid symbol redefinition due to duplicated jumptable (PR42760)

Fix for https://bugs.llvm.org/show_bug.cgi?id=42760. A tBR_JTr
instruction is duplicated by tail duplication, which results in
the same jumptable with the same label being emitted twice.

Fix this by marking tBR_JTr as not duplicable. The corresponding
ARM/Thumb instructions are already marked as not duplicable.
Additionally also mark tTBB_JT and tTBH_JT to be consistent with
Thumb2, even though this shouldn't be strictly necessary.

Differential Revision: https://reviews.llvm.org/D65606

llvm-svn: 367753

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrThumb.td b/llvm/lib/Target/ARM/ARMInstrThumb.td
index b3f4b34c73a..ef2814be2ce 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb.td
@@ -592,6 +592,7 @@ let isBranch = 1, isTerminator = 1, isBarrier = 1 in {
                       [(ARMbrjt tGPR:$target, tjumptable:$jt)]>,
                       Sched<[WriteBrTbl]> {
     let Size = 2;
+    let isNotDuplicable = 1;
     list<Predicate> Predicates = [IsThumb, IsThumb1Only];
   }
 }
@@ -1471,7 +1472,7 @@ def tLEApcrelJT : tPseudoInst<(outs tGPR:$Rd),
 // Thumb-1 doesn't have the TBB or TBH instructions, but we can synthesize them
 // and make use of the same compressed jump table format as Thumb-2.
 let Size = 2, isBranch = 1, isTerminator = 1, isBarrier = 1,
-    isIndirectBranch = 1 in {
+    isIndirectBranch = 1, isNotDuplicable = 1 in {
 def tTBB_JT : tPseudoInst<(outs),
         (ins tGPRwithpc:$base, tGPR:$index, i32imm:$jt, i32imm:$pclbl), 0,
          IIC_Br, []>, Sched<[WriteBr]>;