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|
; RUN: llc -O2 -o - %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: nounwind uwtable
; CHECK-LABEL: tail_dup_merge_loops
; CHECK: # %entry
; CHECK-NOT: # %{{[a-zA-Z_]+}}
; CHECK: # %inner_loop_exit
; CHECK-NOT: # %{{[a-zA-Z_]+}}
; CHECK: # %inner_loop_latch
; CHECK-NOT: # %{{[a-zA-Z_]+}}
; CHECK: # %inner_loop_top
; CHECK-NOT: # %{{[a-zA-Z_]+}}
; CHECK: # %exit
define void @tail_dup_merge_loops(i32 %a, i8* %b, i8* %c) local_unnamed_addr #0 {
entry:
%notlhs674.i = icmp eq i32 %a, 0
br label %outer_loop_top
outer_loop_top: ; preds = %inner_loop_exit, %entry
%dst.0.ph.i = phi i8* [ %b, %entry ], [ %scevgep679.i, %inner_loop_exit ]
br i1 %notlhs674.i, label %exit, label %inner_loop_preheader
inner_loop_preheader: ; preds = %outer_loop_top
br label %inner_loop_top
inner_loop_top: ; preds = %inner_loop_latch, %inner_loop_preheader
%dst.0.i = phi i8* [ %inc, %inner_loop_latch ], [ %dst.0.ph.i, %inner_loop_preheader ]
%var = load i8, i8* %dst.0.i
%tobool1.i = icmp slt i8 %var, 0
br label %inner_loop_test
inner_loop_test: ; preds = %inner_loop_top
br i1 %tobool1.i, label %inner_loop_exit, label %inner_loop_latch
inner_loop_exit: ; preds = %inner_loop_test
%scevgep.i = getelementptr i8, i8* %dst.0.i, i64 1
%scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 0
br label %outer_loop_top
inner_loop_latch: ; preds = %inner_loop_test
%cmp75.i = icmp ult i8* %dst.0.i, %c
%inc = getelementptr i8, i8* %dst.0.i, i64 2
br label %inner_loop_top
exit: ; preds = %outer_loop_top
ret void
}
@.str.6 = external unnamed_addr constant [23 x i8], align 1
; There is an erroneus check in LoopBase::addBasicBlockToLoop(), where it
; assumes that the header block for a loop is unique.
; For most of compilation this assumption is true, but during layout we allow
; this assumption to be violated. The following code will trigger the bug:
; The loops in question is eventually headed by the block shared_loop_header
;
; During layout The block labeled outer_loop_header gets tail-duplicated into
; outer_loop_latch, and into shared_preheader, and then removed. This leaves
; shared_loop_header as the header of both loops. The end result
; is that there are 2 valid loops, and that they share a header. If we re-ran
; the loop analysis, it would classify this as a single loop.
; So far this is fine as far as layout is concerned.
; After layout we tail merge blocks merge_other and merge_predecessor_split.
; We do this even though they share only a single instruction, because
; merge_predecessor_split falls through to their shared successor:
; outer_loop_latch.
; The rest of the blocks in the function are noise unfortunately. Bugpoint
; couldn't shrink the test any further.
; CHECK-LABEL: loop_shared_header
; CHECK: # %entry
; CHECK: # %shared_preheader
; CHECK: # %shared_loop_header
; CHECK: # %inner_loop_body
; CHECK: # %outer_loop_latch
; CHECK: # %merge_predecessor_split
; CHECK: # %outer_loop_latch
; CHECK: # %cleanup
define i32 @loop_shared_header(i8* %exe, i32 %exesz, i32 %headsize, i32 %min, i32 %wwprva, i32 %e_lfanew, i8* readonly %wwp, i32 %wwpsz, i16 zeroext %sects) local_unnamed_addr #0 {
entry:
%0 = load i32, i32* undef, align 4
%mul = shl nsw i32 %0, 2
br i1 undef, label %if.end19, label %cleanup
if.end19: ; preds = %entry
%conv = zext i32 %mul to i64
%call = tail call i8* @cli_calloc(i64 %conv, i64 1)
%1 = icmp eq i32 %exesz, 0
%notrhs = icmp eq i32 %0, 0
%or.cond117.not = or i1 %1, %notrhs
%or.cond202 = or i1 %or.cond117.not, undef
%cmp35 = icmp ult i8* undef, %exe
%or.cond203 = or i1 %or.cond202, %cmp35
br i1 %or.cond203, label %cleanup, label %if.end50
if.end50: ; preds = %if.end19
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* nonnull %call, i8* undef, i64 %conv, i1 false)
%cmp1.i.i = icmp ugt i32 %mul, 3
br i1 %cmp1.i.i, label %shared_preheader, label %wunpsect.exit.thread.loopexit391
shared_preheader: ; preds = %if.end50
br label %outer_loop_header
outer_loop_header: ; preds = %outer_loop_latch, %shared_preheader
%bits.1.i = phi i8 [ 32, %shared_preheader ], [ %bits.43.i, %outer_loop_latch ]
%dst.0.ph.i = phi i8* [ undef, %shared_preheader ], [ %scevgep679.i, %outer_loop_latch ]
%2 = icmp eq i32 undef, 0
br i1 %2, label %while.cond.us1412.i, label %shared_loop_header
while.cond.us1412.i: ; preds = %outer_loop_header
%.pre.i = add i8 %bits.1.i, -1
%tobool2.us1420.i = icmp eq i8 %.pre.i, 0
%or.cond.us1421.i = or i1 undef, %tobool2.us1420.i
br i1 %or.cond.us1421.i, label %if.end41.us1436.i, label %cleanup
if.end41.us1436.i: ; preds = %while.cond.us1412.i
unreachable
shared_loop_header: ; preds = %dup_early2, %dup_early1
%dst.0.i = phi i8* [ undef, %inner_loop_body ], [ %dst.0.ph.i, %outer_loop_header ], [ undef, %dead_block ]
%cmp3.i1172.i = icmp ult i8* undef, %call
br i1 %cmp3.i1172.i, label %wunpsect.exit.thread.loopexit389, label %inner_loop_body
inner_loop_body: ; preds = %shared_loop_header
%3 = icmp slt i32 undef, 0
br i1 %3, label %if.end96.i, label %shared_loop_header
dead_block: ; preds = %inner_loop_body
%cmp75.i = icmp ult i8* %dst.0.i, undef
br label %shared_loop_header
if.end96.i: ; preds = %inner_loop_body
%cmp97.i = icmp ugt i32 undef, 2
br i1 %cmp97.i, label %if.then99.i, label %if.end287.i
if.then99.i: ; preds = %if.end96.i
tail call void (i8*, ...) @cli_dbgmsg(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.6, i64 0, i64 0), i32 undef)
br label %cleanup
if.end287.i: ; preds = %if.end96.i
%cmp291.i = icmp ne i32 undef, 1
%conv294.i = select i1 %cmp291.i, i16 4, i16 3
br i1 undef, label %if.end308.i, label %outer_loop_latch
if.end308.i: ; preds = %if.end287.i
br i1 undef, label %if.end335.i, label %merge_predecessor_split
merge_predecessor_split: ; preds = %if.end308.i
%4 = bitcast i8* undef to i32*
br label %outer_loop_latch
if.end335.i: ; preds = %if.end308.i
br i1 undef, label %outer_loop_latch, label %merge_other
merge_other: ; preds = %if.end335.i
br label %outer_loop_latch
outer_loop_latch: ; preds = %merge_other, %if.end335.i, %merge_predecessor_split, %if.end287.i
%bits.43.i = phi i8 [ undef, %if.end287.i ], [ undef, %merge_other ], [ 32, %merge_predecessor_split ], [ 0, %if.end335.i ]
%backsize.0.i = phi i16 [ %conv294.i, %if.end287.i ], [ 0, %merge_other ], [ 0, %merge_predecessor_split ], [ 0, %if.end335.i ]
%5 = add i16 %backsize.0.i, -1
%6 = zext i16 %5 to i64
%scevgep.i = getelementptr i8, i8* %dst.0.ph.i, i64 1
%scevgep679.i = getelementptr i8, i8* %scevgep.i, i64 %6
br label %outer_loop_header
wunpsect.exit.thread.loopexit389: ; preds = %shared_loop_header
unreachable
wunpsect.exit.thread.loopexit391: ; preds = %if.end50
unreachable
cleanup: ; preds = %if.then99.i, %while.cond.us1412.i, %if.end19, %entry
%retval.0 = phi i32 [ 0, %if.then99.i ], [ 1, %entry ], [ 1, %if.end19 ], [ 1, %while.cond.us1412.i ]
ret i32 %retval.0
}
; Function Attrs: nounwind
declare void @cli_dbgmsg(i8*, ...) local_unnamed_addr #0
; Function Attrs: nounwind
declare i8* @cli_calloc(i64, i64) local_unnamed_addr #0
; Function Attrs: argmemonly nounwind
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i1) #1
attributes #0 = { nounwind }
attributes #1 = { argmemonly nounwind }
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