llvm-6502/test/CodeGen/ARM/rev.ll
Evan Cheng 5fb468a6b3 Canonicalize (srl (bswap x), 16) to (rotr (bswap x), 16) if the high 16 bits
of x are zero. This optimizes rev + lsr 16 to rev16.

rdar://10750814


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151230 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-23 02:58:19 +00:00

127 lines
2.9 KiB
LLVM

; RUN: llc < %s -march=arm -mattr=+v6 | FileCheck %s
define i32 @test1(i32 %X) nounwind {
; CHECK: test1
; CHECK: rev16 r0, r0
%tmp1 = lshr i32 %X, 8
%X15 = bitcast i32 %X to i32
%tmp4 = shl i32 %X15, 8
%tmp2 = and i32 %tmp1, 16711680
%tmp5 = and i32 %tmp4, -16777216
%tmp9 = and i32 %tmp1, 255
%tmp13 = and i32 %tmp4, 65280
%tmp6 = or i32 %tmp5, %tmp2
%tmp10 = or i32 %tmp6, %tmp13
%tmp14 = or i32 %tmp10, %tmp9
ret i32 %tmp14
}
define i32 @test2(i32 %X) nounwind {
; CHECK: test2
; CHECK: revsh r0, r0
%tmp1 = lshr i32 %X, 8
%tmp1.upgrd.1 = trunc i32 %tmp1 to i16
%tmp3 = trunc i32 %X to i16
%tmp2 = and i16 %tmp1.upgrd.1, 255
%tmp4 = shl i16 %tmp3, 8
%tmp5 = or i16 %tmp2, %tmp4
%tmp5.upgrd.2 = sext i16 %tmp5 to i32
ret i32 %tmp5.upgrd.2
}
; rdar://9147637
define i32 @test3(i16 zeroext %a) nounwind {
entry:
; CHECK: test3:
; CHECK: revsh r0, r0
%0 = tail call i16 @llvm.bswap.i16(i16 %a)
%1 = sext i16 %0 to i32
ret i32 %1
}
declare i16 @llvm.bswap.i16(i16) nounwind readnone
define i32 @test4(i16 zeroext %a) nounwind {
entry:
; CHECK: test4:
; CHECK: revsh r0, r0
%conv = zext i16 %a to i32
%shr9 = lshr i16 %a, 8
%conv2 = zext i16 %shr9 to i32
%shl = shl nuw nsw i32 %conv, 8
%or = or i32 %conv2, %shl
%sext = shl i32 %or, 16
%conv8 = ashr exact i32 %sext, 16
ret i32 %conv8
}
; rdar://9609059
define i32 @test5(i32 %i) nounwind readnone {
entry:
; CHECK: test5
; CHECK: revsh r0, r0
%shl = shl i32 %i, 24
%shr = ashr exact i32 %shl, 16
%shr23 = lshr i32 %i, 8
%and = and i32 %shr23, 255
%or = or i32 %shr, %and
ret i32 %or
}
; rdar://9609108
define i32 @test6(i32 %x) nounwind readnone {
entry:
; CHECK: test6
; CHECK: rev16 r0, r0
%and = shl i32 %x, 8
%shl = and i32 %and, 65280
%and2 = lshr i32 %x, 8
%shr11 = and i32 %and2, 255
%shr5 = and i32 %and2, 16711680
%shl9 = and i32 %and, -16777216
%or = or i32 %shr5, %shl9
%or6 = or i32 %or, %shr11
%or10 = or i32 %or6, %shl
ret i32 %or10
}
; rdar://9164521
define i32 @test7(i32 %a) nounwind readnone {
entry:
; CHECK: test7
; CHECK: rev r0, r0
; CHECK: lsr r0, r0, #16
%and = lshr i32 %a, 8
%shr3 = and i32 %and, 255
%and2 = shl i32 %a, 8
%shl = and i32 %and2, 65280
%or = or i32 %shr3, %shl
ret i32 %or
}
define i32 @test8(i32 %a) nounwind readnone {
entry:
; CHECK: test8
; CHECK: revsh r0, r0
%and = lshr i32 %a, 8
%shr4 = and i32 %and, 255
%and2 = shl i32 %a, 8
%or = or i32 %shr4, %and2
%sext = shl i32 %or, 16
%conv3 = ashr exact i32 %sext, 16
ret i32 %conv3
}
; rdar://10750814
define zeroext i16 @test9(i16 zeroext %v) nounwind readnone {
entry:
; CHECK: test9
; CHECK: rev16 r0, r0
%conv = zext i16 %v to i32
%shr4 = lshr i32 %conv, 8
%shl = shl nuw nsw i32 %conv, 8
%or = or i32 %shr4, %shl
%conv3 = trunc i32 %or to i16
ret i16 %conv3
}