llvm-mirror/test/Other/pr32085.ll
Filipe Cabecinhas 812c9f7a7a Simplify the CFG after loop pass cleanup.
Summary:
Otherwise we might end up with some empty basic blocks or
single-entry-single-exit basic blocks.

This fixes PR32085

Reviewers: chandlerc, danielcdh

Subscribers: mehdi_amini, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D30468

llvm-svn: 301395
2017-04-26 12:02:41 +00:00

57 lines
1.2 KiB
LLVM

; RUN: opt -S -O1 < %s -o %t1.ll
;; Show that there's no difference after running another simplify CFG
; RUN: opt -S -simplifycfg < %t1.ll -o %t2.ll
; RUN: diff %t1.ll %t2.ll
; Test from LoopSink pass, leaves some single-entry single-exit basic blocks.
; After LoopSink, we get a basic block .exit.loopexit which has one entry and
; one exit, the only instruction is a branch. Make sure it doesn't show up.
; Make sure they disappear at -O1.
@g = global i32 0, align 4
define i32 @t1(i32, i32) {
%3 = icmp eq i32 %1, 0
br i1 %3, label %.exit, label %.preheader
.preheader:
%invariant = load i32, i32* @g
br label %.b1
.b1:
%iv = phi i32 [ %t7, %.b7 ], [ 0, %.preheader ]
%c1 = icmp sgt i32 %iv, %0
br i1 %c1, label %.b2, label %.b6
.b2:
%c2 = icmp sgt i32 %iv, 1
br i1 %c2, label %.b3, label %.b4
.b3:
%t3 = sub nsw i32 %invariant, %iv
br label %.b5
.b4:
%t4 = add nsw i32 %invariant, %iv
br label %.b5
.b5:
%p5 = phi i32 [ %t3, %.b3 ], [ %t4, %.b4 ]
%t5 = mul nsw i32 %p5, 5
br label %.b7
.b6:
%t6 = add nsw i32 %iv, 100
br label %.b7
.b7:
%p7 = phi i32 [ %t6, %.b6 ], [ %t5, %.b5 ]
%t7 = add nuw nsw i32 %iv, 1
%c7 = icmp eq i32 %t7, %p7
br i1 %c7, label %.b1, label %.exit
.exit:
ret i32 10
}