| ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py |
| ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7 | FileCheck %s |
| |
| ; Verify that DAGCombiner does not crash when checking if it is |
| ; safe to fold the shuffles in function @sample_test according to rule |
| ; (shuffle (shuffle A, Undef, M0), Undef, M1) -> (shuffle A, Undef, M2) |
| ; |
| ; The DAGCombiner avoids folding shuffles if |
| ; the resulting shuffle dag node is not legal for the target. |
| ; That means, the shuffle must have legal type and legal mask. |
| ; |
| ; Before, the DAGCombiner forgot to check if the resulting shuffle |
| ; was legal. It instead just called method |
| ; 'X86TargetLowering::isShuffleMaskLegal'; however, that was not enough since |
| ; that method always expect to have a valid vector type in input. |
| ; As a consequence, compiling the function below would have caused a crash. |
| |
| define void @sample_test() { |
| ; CHECK-LABEL: sample_test: |
| ; CHECK: # %bb.0: |
| ; CHECK-NEXT: xorl %eax, %eax |
| ; CHECK-NEXT: testb %al, %al |
| ; CHECK-NEXT: jne .LBB0_2 |
| ; CHECK-NEXT: # %bb.1: |
| ; CHECK-NEXT: movd {{.*#+}} xmm0 = mem[0],zero,zero,zero |
| ; CHECK-NEXT: punpcklbw {{.*#+}} xmm0 = xmm0[0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7] |
| ; CHECK-NEXT: pshuflw {{.*#+}} xmm0 = xmm0[0,2,2,3,4,5,6,7] |
| ; CHECK-NEXT: movd %xmm0, (%rax) |
| ; CHECK-NEXT: .LBB0_2: |
| ; CHECK-NEXT: retq |
| br i1 undef, label %5, label %1 |
| |
| ; <label>:1 ; preds = %0 |
| %2 = load <4 x i8>, <4 x i8>* undef |
| %3 = shufflevector <4 x i8> %2, <4 x i8> undef, <4 x i32> <i32 2, i32 2, i32 0, i32 0> |
| %4 = shufflevector <4 x i8> %3, <4 x i8> undef, <4 x i32> <i32 2, i32 3, i32 0, i32 1> |
| store <4 x i8> %4, <4 x i8>* undef |
| br label %5 |
| |
| ; <label>:5 ; preds = %1, %0 |
| ret void |
| } |
| |