1 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7 2 3 ; Verify that DAGCombiner does not crash when checking if it is 4 ; safe to fold the shuffles in function @sample_test according to rule 5 ; (shuffle (shuffle A, Undef, M0), Undef, M1) -> (shuffle A, Undef, M2) 6 ; 7 ; The DAGCombiner avoids folding shuffles if 8 ; the resulting shuffle dag node is not legal for the target. 9 ; That means, the shuffle must have legal type and legal mask. 10 ; 11 ; Before, the DAGCombiner forgot to check if the resulting shuffle 12 ; was legal. It instead just called method 13 ; 'X86TargetLowering::isShuffleMaskLegal'; however, that was not enough since 14 ; that method always expect to have a valid vector type in input. 15 ; As a consequence, compiling the function below would have caused a crash. 16 17 define void @sample_test() { 18 br i1 undef, label %5, label %1 19 20 ; <label>:1 ; preds = %0 21 %2 = load <4 x i8>, <4 x i8>* undef 22 %3 = shufflevector <4 x i8> %2, <4 x i8> undef, <4 x i32> <i32 2, i32 2, i32 0, i32 0> 23 %4 = shufflevector <4 x i8> %3, <4 x i8> undef, <4 x i32> <i32 2, i32 3, i32 0, i32 1> 24 store <4 x i8> %4, <4 x i8>* undef 25 br label %5 26 27 ; <label>:5 ; preds = %1, %0 28 ret void 29 } 30 31
