tbb / tbh instructions only branch forward, not backwards.

llvm-svn: 77522

diff --git a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
index aad5eb7..bc9e11b 100644 (file)
--- a/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/llvm/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -1358,10 +1358,12 @@ bool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) {
     for (unsigned j = 0, ee = JTBBs.size(); j != ee; ++j) {
       MachineBasicBlock *MBB = JTBBs[j];
       unsigned DstOffset = BBOffsets[MBB->getNumber()];
-      if (ByteOk && !OffsetIsInRange(JTOffset, DstOffset, (1<<8)-1, true, false))
+      // Negative offset is not ok. FIXME: We should change BB layout to make
+      // sure all the branches are forward.
+      if (ByteOk && !OffsetIsInRange(JTOffset, DstOffset, (1<<8)-1, false))
         ByteOk = false;
       if (HalfWordOk &&
-          !OffsetIsInRange(JTOffset, DstOffset, (1<<16)-1, true, false))
+          !OffsetIsInRange(JTOffset, DstOffset, (1<<16)-1, false))
         HalfWordOk = false;
       if (!ByteOk && !HalfWordOk)
         break;

diff --git a/llvm/test/CodeGen/Thumb2/thumb2-jtb.ll b/llvm/test/CodeGen/Thumb2/thumb2-jtb.ll
new file mode 100644 (file)
index 0000000..ee483ac
--- /dev/null
+++ b/llvm/test/CodeGen/Thumb2/thumb2-jtb.ll
@@ -0,0 +1,120 @@
+; RUN: llvm-as < %s | llc -march=thumb -mattr=+thumb2 | not grep tbb
+
+; Do not use tbb / tbh if any destination is before the jumptable.
+; rdar://7102917
+
+define i16 @main__getopt_internal_2E_exit_2E_ce(i32) nounwind {
+newFuncRoot:
+       br label %_getopt_internal.exit.ce
+
+codeRepl127.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 0
+
+parse_options.exit.loopexit.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 1
+
+bb1.i.exitStub:                ; preds = %_getopt_internal.exit.ce
+       ret i16 2
+
+bb90.i.exitStub:               ; preds = %_getopt_internal.exit.ce
+       ret i16 3
+
+codeRepl104.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 4
+
+codeRepl113.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 5
+
+codeRepl51.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 6
+
+codeRepl70.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 7
+
+codeRepl119.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 8
+
+codeRepl93.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 9
+
+codeRepl101.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 10
+
+codeRepl120.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 11
+
+codeRepl89.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 12
+
+codeRepl45.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 13
+
+codeRepl58.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 14
+
+codeRepl46.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 15
+
+codeRepl50.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 16
+
+codeRepl52.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 17
+
+codeRepl53.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 18
+
+codeRepl61.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 19
+
+codeRepl85.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 20
+
+codeRepl97.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 21
+
+codeRepl79.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 22
+
+codeRepl102.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 23
+
+codeRepl54.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 24
+
+codeRepl57.exitStub:           ; preds = %_getopt_internal.exit.ce
+       ret i16 25
+
+codeRepl103.exitStub:          ; preds = %_getopt_internal.exit.ce
+       ret i16 26
+
+_getopt_internal.exit.ce:              ; preds = %newFuncRoot
+       switch i32 %0, label %codeRepl127.exitStub [
+               i32 -1, label %parse_options.exit.loopexit.exitStub
+               i32 0, label %bb1.i.exitStub
+               i32 63, label %bb90.i.exitStub
+               i32 66, label %codeRepl104.exitStub
+               i32 67, label %codeRepl113.exitStub
+               i32 71, label %codeRepl51.exitStub
+               i32 77, label %codeRepl70.exitStub
+               i32 78, label %codeRepl119.exitStub
+               i32 80, label %codeRepl93.exitStub
+               i32 81, label %codeRepl101.exitStub
+               i32 82, label %codeRepl120.exitStub
+               i32 88, label %codeRepl89.exitStub
+               i32 97, label %codeRepl45.exitStub
+               i32 98, label %codeRepl58.exitStub
+               i32 99, label %codeRepl46.exitStub
+               i32 100, label %codeRepl50.exitStub
+               i32 104, label %codeRepl52.exitStub
+               i32 108, label %codeRepl53.exitStub
+               i32 109, label %codeRepl61.exitStub
+               i32 110, label %codeRepl85.exitStub
+               i32 111, label %codeRepl97.exitStub
+               i32 113, label %codeRepl79.exitStub
+               i32 114, label %codeRepl102.exitStub
+               i32 115, label %codeRepl54.exitStub
+               i32 116, label %codeRepl57.exitStub
+               i32 118, label %codeRepl103.exitStub
+       ]
+}

diff --git a/llvm/test/CodeGen/Thumb2/thumb2-tbh.ll b/llvm/test/CodeGen/Thumb2/thumb2-tbh.ll
index d15bf58..3a6d758 100644 (file)
--- a/llvm/test/CodeGen/Thumb2/thumb2-tbh.ll
+++ b/llvm/test/CodeGen/Thumb2/thumb2-tbh.ll
@@ -1,5 +1,9 @@
 ; RUN: llvm-as < %s | llc -mtriple=thumbv7-apple-darwin -relocation-model=pic | FileCheck %s
 
+; Thumb2 target should reorder the bb's in order to use tbb / tbh.
+
+; XFAIL: *
+
        %struct.R_flstr = type { i32, i32, i8* }
        %struct._T_tstr = type { i32, %struct.R_flstr*, %struct._T_tstr* }
 @_C_nextcmd = external global i32              ; <i32*> [#uses=3]