llvm-6502/test/CodeGen/X86/extractelement-shuffle.ll
Mon P Wang bae527d949 Fixed a bug when trying to optimize a extract vector element of a
bit convert that changes the number of elements of a shuffle.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60829 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-10 03:59:02 +00:00

13 lines
576 B
LLVM

; RUN: llvm-as < %s | llc
; Examples that exhibits a bug in DAGCombine. The case is triggered by the
; following program. The bug is DAGCombine assumes that the bit convert
; preserves the number of elements so the optimization code tries to read
; through the 3rd mask element, which doesn't exist.
define i32 @update(<2 x i64> %val1, <2 x i64> %val2) nounwind readnone {
entry:
%shuf = shufflevector <2 x i64> %val1, <2 x i64> %val2, <2 x i32> <i32 0, i32 3>;
%bit = bitcast <2 x i64> %shuf to <4 x i32>;
%res = extractelement <4 x i32> %bit, i32 3;
ret i32 %res;
}