; RUN: llc -mtriple=x86_64-- -O2 -start-after=stack-protector -stop-before=loops %s -o - | FileCheck %s ; This test verifies the fix for PR33368. ; ; The expected outcome of the operation is to store bytes 0 and 2 of the incoming ; parameter into c2 (a 2 x i8 vector). DAGCombine converts shuffles into a ; sequence of extend and subsequent truncate operations. The bug was that an extension ; by 4 followed by a truncation by 8 was completely eliminated. ; The test checks for the correct sequence of operations that results from the ; preservation of the extend/truncate operations mentioned above (2 extend and ; 3 truncate instructions). ; ; NOTE: This operation could be collapsed in to a single truncate. Once that is done ; this test will have to be adjusted. ; CHECK: PANDrm ; CHECK: PACKUSWBrr ; CHECK: MOVPDI2DIrr define void @test(double %vec.coerce) local_unnamed_addr { entry: %c2 = alloca <2 x i8>, align 2 %0 = bitcast double %vec.coerce to <8 x i8> %1 = shufflevector <8 x i8> %0, <8 x i8> undef, <4 x i32> %2 = shufflevector <4 x i8> %1, <4 x i8> undef, <2 x i32> store volatile <2 x i8> %2, <2 x i8>* %c2, align 2 br label %if.end if.end: %3 = bitcast <2 x i8> %2 to i16 ret void }