; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5 ; RUN: llc < %s -mtriple=x86_64-- -O2 | 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. define void @test(double %vec.coerce) local_unnamed_addr { ; CHECK-LABEL: test: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: pand {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0 ; CHECK-NEXT: packuswb %xmm0, %xmm0 ; CHECK-NEXT: movd %xmm0, %eax ; CHECK-NEXT: movw %ax, -{{[0-9]+}}(%rsp) ; CHECK-NEXT: retq 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, ptr %c2, align 2 br label %if.end if.end: %3 = bitcast <2 x i8> %2 to i16 ret void }