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| ; 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> <i32 2, i32 undef, i32 undef, i32 0>
%2 = shufflevector <4 x i8> %1, <4 x i8> undef, <2 x i32> <i32 3, i32 0>
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
}
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