test for and-tst peephole optimization

documents the status-quo with its opportunities

llvm-svn: 113838
This commit is contained in:
Gabor Greif 2010-09-14 08:50:43 +00:00
parent 3d2aa0da5f
commit 40a8053a15

View File

@ -0,0 +1,58 @@
; RUN: llc < %s -mtriple=arm-apple-darwin | FileCheck %s
; RUN: llc < %s -mtriple=thumbv6-apple-darwin | FileCheck -check-prefix=T2 %s
%struct.Foo = type { i8* }
define %struct.Foo* @_ZN3Foo7collectEj(%struct.Foo* %this, i32 %acc) nounwind readonly align 2 {
entry:
%scevgep = getelementptr %struct.Foo* %this, i32 1
br label %tailrecurse
tailrecurse: ; preds = %sw.bb, %entry
%lsr.iv2 = phi %struct.Foo* [ %scevgep3, %sw.bb ], [ %scevgep, %entry ]
%lsr.iv = phi i32 [ %lsr.iv.next, %sw.bb ], [ 1, %entry ]
%acc.tr = phi i32 [ %or, %sw.bb ], [ %acc, %entry ]
%lsr.iv24 = bitcast %struct.Foo* %lsr.iv2 to i8**
%scevgep5 = getelementptr i8** %lsr.iv24, i32 -1
%tmp2 = load i8** %scevgep5
%0 = ptrtoint i8* %tmp2 to i32
; CHECK: and lr, r12, #3
; CHECK-NEXT: tst r12, #3
; CHECK-NEXT: beq LBB0_4
; T2: movs r5, #3
; T2-NEXT: mov r6, r4
; T2-NEXT: ands r6, r5
; T2-NEXT: tst r4, r5
; T2-NEXT: beq LBB0_5
%and = and i32 %0, 3
%tst = icmp eq i32 %and, 0
br i1 %tst, label %sw.bb, label %tailrecurse.switch
tailrecurse.switch: ; preds = %tailrecurse
switch i32 %and, label %sw.epilog [
i32 1, label %sw.bb
i32 3, label %sw.bb6
i32 2, label %sw.bb8
]
sw.bb: ; preds = %tailrecurse.switch, %tailrecurse
%shl = shl i32 %acc.tr, 1
%or = or i32 %and, %shl
%lsr.iv.next = add i32 %lsr.iv, 1
%scevgep3 = getelementptr %struct.Foo* %lsr.iv2, i32 1
br label %tailrecurse
sw.bb6: ; preds = %tailrecurse.switch
ret %struct.Foo* %lsr.iv2
sw.bb8: ; preds = %tailrecurse.switch
%tmp1 = add i32 %acc.tr, %lsr.iv
%add.ptr11 = getelementptr inbounds %struct.Foo* %this, i32 %tmp1
ret %struct.Foo* %add.ptr11
sw.epilog: ; preds = %tailrecurse.switch
ret %struct.Foo* undef
}