llvm/llvm/test/CodeGen/ARM/tail-dup.ll

; RUN: llc < %s -mtriple=thumb-apple-darwin -relocation-model=dynamic-no-pic -mcpu=cortex-a8 -asm-verbose=false | FileCheck %s

; We should be able to tail-duplicate the basic block containing the indirectbr
; into all of its predecessors.
; CHECK-LABEL: fn:
; CHECK: mov pc
; CHECK: mov pc
; CHECK: mov pc

@fn.codetable = internal unnamed_addr constant [3 x ptr] [ptr blockaddress(@fn, %RETURN), ptr blockaddress(@fn, %INCREMENT), ptr blockaddress(@fn, %DECREMENT)], align 4

define i32 @fn(ptr nocapture %opcodes) nounwind readonly ssp {
entry:
  %0 = load i32, ptr %opcodes, align 4
  %arrayidx = getelementptr inbounds [3 x ptr], ptr @fn.codetable, i32 0, i32 %0
  br label %indirectgoto

INCREMENT:                                        ; preds = %indirectgoto
  %inc = add nsw i32 %result.0, 1
  %1 = load i32, ptr %opcodes.addr.0, align 4
  %arrayidx2 = getelementptr inbounds [3 x ptr], ptr @fn.codetable, i32 0, i32 %1
  br label %indirectgoto

DECREMENT:                                        ; preds = %indirectgoto
  %dec = add nsw i32 %result.0, -1
  %2 = load i32, ptr %opcodes.addr.0, align 4
  %arrayidx4 = getelementptr inbounds [3 x ptr], ptr @fn.codetable, i32 0, i32 %2
  br label %indirectgoto

indirectgoto:                                     ; preds = %DECREMENT, %INCREMENT, %entry
  %result.0 = phi i32 [ 0, %entry ], [ %dec, %DECREMENT ], [ %inc, %INCREMENT ]
  %opcodes.pn = phi ptr [ %opcodes, %entry ], [ %opcodes.addr.0, %DECREMENT ], [ %opcodes.addr.0, %INCREMENT ]
  %indirect.goto.dest.in = phi ptr [ %arrayidx, %entry ], [ %arrayidx4, %DECREMENT ], [ %arrayidx2, %INCREMENT ]
  %opcodes.addr.0 = getelementptr inbounds i32, ptr %opcodes.pn, i32 1
  %indirect.goto.dest = load ptr, ptr %indirect.goto.dest.in, align 4
  indirectbr ptr %indirect.goto.dest, [label %RETURN, label %INCREMENT, label %DECREMENT]

RETURN:                                           ; preds = %indirectgoto
  ret i32 %result.0
}