diff options
| author | Eric Christopher <echristo@apple.com> | 2012-04-10 18:18:10 +0000 |
|---|---|---|
| committer | Eric Christopher <echristo@apple.com> | 2012-04-10 18:18:10 +0000 |
| commit | 18112d83e7d54597bcd5870fb411c7997e02bc1e (patch) | |
| tree | 0792eea6377628b357d274eaf1e2bf8eb48ca611 | |
| parent | b79855ee181b0a74507022894b0f753af0041121 (diff) | |
| download | external_llvm-18112d83e7d54597bcd5870fb411c7997e02bc1e.zip external_llvm-18112d83e7d54597bcd5870fb411c7997e02bc1e.tar.gz external_llvm-18112d83e7d54597bcd5870fb411c7997e02bc1e.tar.bz2 | |
To ensure that we have more accurate line information for a block
don't elide the branch instruction if it's the only one in the block,
otherwise it's ok.
PR9796 and rdar://11215207
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154417 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/SelectionDAG/FastISel.cpp | 7 | ||||
| -rw-r--r-- | test/CodeGen/ARM/fast-isel-br-const.ll | 3 |
2 files changed, 7 insertions, 3 deletions
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp index 5de6667..0c1ac69 100644 --- a/lib/CodeGen/SelectionDAG/FastISel.cpp +++ b/lib/CodeGen/SelectionDAG/FastISel.cpp @@ -821,8 +821,11 @@ FastISel::SelectInstruction(const Instruction *I) { /// the CFG. void FastISel::FastEmitBranch(MachineBasicBlock *MSucc, DebugLoc DL) { - if (FuncInfo.MBB->isLayoutSuccessor(MSucc)) { - // The unconditional fall-through case, which needs no instructions. + + if (FuncInfo.MBB->getBasicBlock()->size() > 1 && FuncInfo.MBB->isLayoutSuccessor(MSucc)) { + // For more accurate line information if this is the only instruction + // in the block then emit it, otherwise we have the unconditional + // fall-through case, which needs no instructions. } else { // The unconditional branch case. TII.InsertBranch(*FuncInfo.MBB, MSucc, NULL, diff --git a/test/CodeGen/ARM/fast-isel-br-const.ll b/test/CodeGen/ARM/fast-isel-br-const.ll index 625adc2..7c532d5 100644 --- a/test/CodeGen/ARM/fast-isel-br-const.ll +++ b/test/CodeGen/ARM/fast-isel-br-const.ll @@ -5,7 +5,7 @@ define i32 @t1(i32 %a, i32 %b) nounwind uwtable ssp { entry: ; THUMB: t1: ; ARM: t1: - + %x = add i32 %a, %b br i1 1, label %if.then, label %if.else ; THUMB-NOT: b LBB0_1 ; ARM-NOT: b LBB0_1 @@ -24,6 +24,7 @@ if.then2: ; preds = %if.else br label %if.end6 if.else3: ; preds = %if.else + %y = sub i32 %a, %b br i1 1, label %if.then5, label %if.end ; THUMB-NOT: b LBB0_5 ; ARM-NOT: b LBB0_5 |