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

[SCEV] Add a few test cases where the max BTC is limited by wrapping.

This commit is contained in:
Florian Hahn 2020-10-16 09:52:43 +01:00
parent e2af9bd611
commit e034c3f704
1 changed files with 48 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
llvm/test/Analysis/ScalarEvolution/max-backedge-taken-count-limit-by-wrapping.ll Normal file
View File

@ -0,0 +1,48 @@
; RUN: opt < %s -analyze -enable-new-pm=0 -scalar-evolution -scalar-evolution-max-iterations=0 -scalar-evolution-classify-expressions=0 | FileCheck %s
; RUN: opt < %s -disable-output "-passes=print<scalar-evolution>" -scalar-evolution-max-iterations=0 -scalar-evolution-classify-expressions=0 2>&1 | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
define void @max_backedge_taken_count_by_wrapping1(i8 %N, i8* %ptr) {
; CHECK-LABEL: Determining loop execution counts for: @max_backedge_taken_count_by_wrapping1
; CHECK-NEXT: Loop %loop: backedge-taken count is (%N /u 4)
; CHECK-NEXT: Loop %loop: max backedge-taken count is 63
; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is (%N /u 4)
;
entry:
br label %loop
loop:
%iv = phi i8 [ 0, %entry ], [ %iv.next, %loop ]
%gep = getelementptr i8, i8* %ptr, i8 %iv
store i8 %iv, i8* %gep
%iv.next = add nuw nsw i8 %iv, 4
%ec = icmp ne i8 %iv, %N
br i1 %ec, label %loop, label %exit
exit:
ret void
}
; TODO: Max backedge taken count could be improved.
define void @max_backedge_taken_count_by_wrapping2(i8 %N, i8* %ptr) {
; CHECK-LABEL: Determining loop execution counts for: @max_backedge_taken_count_by_wrapping2
; CHECK-NEXT: Loop %loop: backedge-taken count is ((-128 + %N) /u 4)
; CHECK-NEXT: Loop %loop: max backedge-taken count is 63
; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-128 + %N) /u 4)
;
entry:
br label %loop
loop:
%iv = phi i8 [ 128, %entry ], [ %iv.next, %loop ]
%gep = getelementptr i8, i8* %ptr, i8 %iv
store i8 %iv, i8* %gep
%iv.next = add nuw nsw i8 %iv, 4
%ec = icmp ne i8 %iv, %N
br i1 %ec, label %loop, label %exit
exit:
ret void
}