new bswap idiom

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32012 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-11-29 07:21:08 +00:00
parent 46b96055cf
commit 71d8f4d84a

View File

@ -1,4 +1,4 @@
; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep 'call.*llvm.bswap' | wc -l | grep 4
; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep 'call.*llvm.bswap' | wc -l | grep 5
uint %test1(uint %i) {
%tmp1 = shr uint %i, ubyte 24 ; <uint> [#uses=1]
@ -40,3 +40,22 @@ ushort %test4(ushort %s) {
ret ushort %tmp5
}
; unsigned short test5(unsigned short a) {
; return ((a & 0xff00) >> 8 | (a & 0x00ff) << 8);
;}
ushort %test5(ushort %a) {
%tmp = zext ushort %a to int
%tmp1 = and int %tmp, 65280
%tmp2 = ashr int %tmp1, ubyte 8
%tmp2 = trunc int %tmp2 to short
%tmp3 = zext ushort %a to int
%tmp4 = and int %tmp3, 255
%tmp5 = shl int %tmp4, ubyte 8
%tmp5 = trunc int %tmp5 to short
%tmp = or short %tmp2, %tmp5
%tmp6 = bitcast short %tmp to ushort
%tmp6 = zext ushort %tmp6 to int
%retval = trunc int %tmp6 to ushort
ret ushort %retval
}