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llvm-mirror/test/Analysis/ScalarEvolution/trip-count12.ll
Tim Northover e0b9ad8443 Revert "[SCEV] add no wrap flag for SCEVAddExpr."
This reverts r366419 because the analysis performed is within the context of
the loop and it's only valid to add wrapping flags to "global" expressions if
they're always correct.

llvm-svn: 373184
2019-09-30 07:46:52 +00:00

36 lines
1.4 KiB
LLVM

; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
; CHECK: Determining loop execution counts for: @test
; CHECK: Loop %for.body: backedge-taken count is ((-2 + %len) /u 2)
; CHECK: Loop %for.body: max backedge-taken count is 1073741823
define zeroext i16 @test(i16* nocapture %p, i32 %len) nounwind readonly {
entry:
%cmp2 = icmp sgt i32 %len, 1
br i1 %cmp2, label %for.body.preheader, label %for.end
for.body.preheader: ; preds = %entry
br label %for.body
for.body: ; preds = %for.body, %for.body.preheader
%p.addr.05 = phi i16* [ %incdec.ptr, %for.body ], [ %p, %for.body.preheader ]
%len.addr.04 = phi i32 [ %sub, %for.body ], [ %len, %for.body.preheader ]
%res.03 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ]
%incdec.ptr = getelementptr inbounds i16, i16* %p.addr.05, i32 1
%0 = load i16, i16* %p.addr.05, align 2
%conv = zext i16 %0 to i32
%add = add i32 %conv, %res.03
%sub = add nsw i32 %len.addr.04, -2
%cmp = icmp sgt i32 %sub, 1
br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
for.cond.for.end_crit_edge: ; preds = %for.body
%extract.t = trunc i32 %add to i16
br label %for.end
for.end: ; preds = %for.cond.for.end_crit_edge, %entry
%res.0.lcssa.off0 = phi i16 [ %extract.t, %for.cond.for.end_crit_edge ], [ 0, %entry ]
ret i16 %res.0.lcssa.off0
}