forked from OSchip/llvm-project
36 lines
1.3 KiB
LLVM
36 lines
1.3 KiB
LLVM
; 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 is collapsed to a single truncate, so this test no longer covers
|
|
; what it originally intended to.
|
|
|
|
; CHECK: PUNPCKLQDQrr
|
|
; CHECK: PSHUFHWri
|
|
; CHECK: PACKUSWBrr
|
|
; 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
|
|
}
|