1 ; RUN: llc -mtriple=x86_64-- -O2 -start-after=stack-protector -stop-before=loops %s -o - | FileCheck %s 2 3 ; This test verifies the fix for PR33368. 4 ; 5 ; The expected outcome of the operation is to store bytes 0 and 2 of the incoming 6 ; parameter into c2 (a 2 x i8 vector). DAGCombine converts shuffles into a 7 ; sequence of extend and subsequent truncate operations. The bug was that an extension 8 ; by 4 followed by a truncation by 8 was completely eliminated. 9 10 ; The test checks for the correct sequence of operations that results from the 11 ; preservation of the extend/truncate operations mentioned above (2 extend and 12 ; 3 truncate instructions). 13 ; 14 ; NOTE: This operation could be collapsed in to a single truncate. Once that is done 15 ; this test will have to be adjusted. 16 17 ; CHECK: PUNPCKLBWrr 18 ; CHECK: PUNPCKLWDrr 19 ; CHECK: PANDrm 20 ; CHECK: PACKUSWBrr 21 ; CHECK: PACKUSWBrr 22 ; CHECK: PACKUSWBrr 23 ; CHECK: MOVPDI2DIrr 24 25 define void @test(double %vec.coerce) local_unnamed_addr { 26 entry: 27 %c2 = alloca <2 x i8>, align 2 28 %0 = bitcast double %vec.coerce to <8 x i8> 29 %1 = shufflevector <8 x i8> %0, <8 x i8> undef, <4 x i32> <i32 2, i32 undef, i32 undef, i32 0> 30 %2 = shufflevector <4 x i8> %1, <4 x i8> undef, <2 x i32> <i32 3, i32 0> 31 store volatile <2 x i8> %2, <2 x i8>* %c2, align 2 32 br label %if.end 33 34 if.end: 35 %3 = bitcast <2 x i8> %2 to i16 36 ret void 37 } 38
