diff options
| -rw-r--r-- | lib/CodeGen/RegAllocLocal.cpp | 6 | ||||
| -rw-r--r-- | test/CodeGen/ARM/2009-05-07-RegAllocLocal.ll | 12 |
2 files changed, 16 insertions, 2 deletions
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp index 5ebecc3..e1cc20c 100644 --- a/lib/CodeGen/RegAllocLocal.cpp +++ b/lib/CodeGen/RegAllocLocal.cpp @@ -981,10 +981,12 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) { } } - // Finally, if this is a noop copy instruction, zap it. + // Finally, if this is a noop copy instruction, zap it. (Except that if + // the copy is dead, it must be kept to avoid messing up liveness info for + // the register scavenger. See pr4100.) unsigned SrcReg, DstReg, SrcSubReg, DstSubReg; if (TII->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg) && - SrcReg == DstReg) + SrcReg == DstReg && DeadDefs.empty()) MBB.erase(MI); } diff --git a/test/CodeGen/ARM/2009-05-07-RegAllocLocal.ll b/test/CodeGen/ARM/2009-05-07-RegAllocLocal.ll new file mode 100644 index 0000000..d03b7ce --- /dev/null +++ b/test/CodeGen/ARM/2009-05-07-RegAllocLocal.ll @@ -0,0 +1,12 @@ +; RUN: llvm-as < %s | llc -mtriple=armv5-unknown-linux-gnueabi -O0 -regalloc=local +; PR4100 +@.str = external constant [30 x i8] ; <[30 x i8]*> [#uses=1] + +define i16 @fn16(i16 %arg0.0, <2 x i16> %arg1, i16 %arg2.0) nounwind { +entry: + store <2 x i16> %arg1, <2 x i16>* null + %0 = call i32 (i8*, ...)* @printf(i8* getelementptr ([30 x i8]* @.str, i32 0, i32 0), i32 0) nounwind ; <i32> [#uses=0] + ret i16 0 +} + +declare i32 @printf(i8*, ...) nounwind |