llvm/test/CodeGen/Thumb2/thumb2-tst2.ll
Evan Cheng e721f5c8d3 Improve codegen for select's:
if (x != 0) x = 1
if (x == 1) x = 1

Previous codegen looks like this:
        mov     r1, r0
        cmp     r1, #1
        mov     r0, #0
        moveq   r0, #1

The naive lowering select between two different values. It should recognize the
test is equality test so it's more a conditional move rather than a select:
        cmp     r0, #1
        movne   r0, #0

rdar://9758317


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135017 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-13 00:42:17 +00:00

59 lines
1.3 KiB
LLVM

; RUN: llc < %s -march=thumb -mattr=+thumb2 -join-physregs | FileCheck %s
; These tests implicitly depend on 'movs r0, #0' being rematerialized below the
; tst as 'mov.w r0, #0'. So far, that requires physreg joining.
define i1 @f2(i32 %a, i32 %b) {
; CHECK: f2:
; CHECK: tst r0, r1
%tmp = and i32 %a, %b
%tmp1 = icmp eq i32 %tmp, 0
ret i1 %tmp1
}
define i1 @f4(i32 %a, i32 %b) {
; CHECK: f4:
; CHECK: tst r0, r1
%tmp = and i32 %a, %b
%tmp1 = icmp eq i32 0, %tmp
ret i1 %tmp1
}
define i1 @f6(i32 %a, i32 %b) {
; CHECK: f6:
; CHECK: tst.w r0, r1, lsl #5
%tmp = shl i32 %b, 5
%tmp1 = and i32 %a, %tmp
%tmp2 = icmp eq i32 %tmp1, 0
ret i1 %tmp2
}
define i1 @f7(i32 %a, i32 %b) {
; CHECK: f7:
; CHECK: tst.w r0, r1, lsr #6
%tmp = lshr i32 %b, 6
%tmp1 = and i32 %a, %tmp
%tmp2 = icmp eq i32 %tmp1, 0
ret i1 %tmp2
}
define i1 @f8(i32 %a, i32 %b) {
; CHECK: f8:
; CHECK: tst.w r0, r1, asr #7
%tmp = ashr i32 %b, 7
%tmp1 = and i32 %a, %tmp
%tmp2 = icmp eq i32 %tmp1, 0
ret i1 %tmp2
}
define i1 @f9(i32 %a, i32 %b) {
; CHECK: f9:
; CHECK: tst.w r0, r0, ror #8
%l8 = shl i32 %a, 24
%r8 = lshr i32 %a, 8
%tmp = or i32 %l8, %r8
%tmp1 = and i32 %a, %tmp
%tmp2 = icmp eq i32 %tmp1, 0
ret i1 %tmp2
}