maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[test] Add a SCEV backedge computation test with an explicit zero stride

This commit is contained in:
Philip Reames 2021-07-13 10:57:44 -07:00
parent ce25eb0b71
commit 6245252d4c
1 changed files with 50 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
llvm/test/Analysis/ScalarEvolution/trip-count-unknown-stride.ll
View File

@ -106,5 +106,55 @@ for.end: ; preds = %for.body, %entry
ret void
}
; FIXME: Currently we are more conservative for known zero stride than
; for unknown but potentially zero stride.
; CHECK: Determining loop execution counts for: @zero_stride
; CHECK: Loop %for.body: Unpredictable backedge-taken count.
; CHECK: Loop %for.body: Unpredictable max backedge-taken count.
; CHECK: Loop %for.body: Unpredictable predicated backedge-taken count.
; Note that this function is well defined only when %n <=s 0
define void @zero_stride(i32* nocapture %A, i32 %n) {
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%i.05 = phi i32 [ %add, %for.body ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32, i32* %A, i32 %i.05
%0 = load i32, i32* %arrayidx, align 4
%inc = add nsw i32 %0, 1
store i32 %inc, i32* %arrayidx, align 4
%add = add nsw i32 %i.05, 0
%cmp = icmp slt i32 %add, %n
br i1 %cmp, label %for.body, label %for.end, !llvm.loop !8
for.end: ; preds = %for.body, %entry
ret void
}
; CHECK: Determining loop execution counts for: @zero_stride_ub
; CHECK: Loop %for.body: Unpredictable backedge-taken count.
; CHECK: Loop %for.body: Unpredictable max backedge-taken count.
; CHECK: Loop %for.body: Unpredictable predicated backedge-taken count.
; Note that this function will always execute undefined behavior and thus
; any value is valid for a backedge taken count.
define void @zero_stride_ub(i32* nocapture %A, i32 %n, i32 %s) {
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%i.05 = phi i32 [ %add, %for.body ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i32, i32* %A, i32 %i.05
%0 = load i32, i32* %arrayidx, align 4
%inc = add nsw i32 %0, 1
store i32 %inc, i32* %arrayidx, align 4
%add = add nsw i32 %i.05, 0
%cmp = icmp slt i32 %add, 2
br i1 %cmp, label %for.body, label %for.end, !llvm.loop !8
for.end: ; preds = %for.body, %entry
ret void
}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}