xref: /llvm-project/llvm/test/Transforms/LoopUnroll/runtime-loop-known-exit.ll (revision 5103ef64fe4f60cc0fd518b514c712f4b4c03d98)
16ecc9921SNikita Popov; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2*5103ef64SRoman Lebedev; RUN: opt -S -passes=loop-unroll -unroll-runtime -unroll-runtime-multi-exit < %s | FileCheck %s
36ecc9921SNikita Popov
46ecc9921SNikita Popov; This loop has a known trip count on the non-latch exit. When performing
56ecc9921SNikita Popov; runtime unrolling (at least when using a prologue rather than epilogue) we
66ecc9921SNikita Popov; should not fold that exit based on known trip count information prior to
76ecc9921SNikita Popov; prologue insertion, as that may change the trip count for the modified loop.
86ecc9921SNikita Popov
96ecc9921SNikita Popovdefine void @test(i32 %s, i32 %n) {
106ecc9921SNikita Popov; CHECK-LABEL: @test(
116ecc9921SNikita Popov; CHECK-NEXT:  entry:
126ecc9921SNikita Popov; CHECK-NEXT:    [[N2:%.*]] = add i32 [[S:%.*]], 123
136ecc9921SNikita Popov; CHECK-NEXT:    br label [[LOOP:%.*]]
146ecc9921SNikita Popov; CHECK:       loop:
151ae266f4SNikita Popov; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[S]], [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[LATCH:%.*]] ]
166ecc9921SNikita Popov; CHECK-NEXT:    [[C1:%.*]] = icmp eq i32 [[I]], [[N2]]
171ae266f4SNikita Popov; CHECK-NEXT:    br i1 [[C1]], label [[EXIT1:%.*]], label [[LATCH]]
186ecc9921SNikita Popov; CHECK:       latch:
191ae266f4SNikita Popov; CHECK-NEXT:    [[C2:%.*]] = icmp eq i32 [[I]], [[N:%.*]]
201ae266f4SNikita Popov; CHECK-NEXT:    [[I_INC]] = add i32 [[I]], 1
211ae266f4SNikita Popov; CHECK-NEXT:    br i1 [[C2]], label [[EXIT2:%.*]], label [[LOOP]]
226ecc9921SNikita Popov; CHECK:       exit1:
236ecc9921SNikita Popov; CHECK-NEXT:    ret void
246ecc9921SNikita Popov; CHECK:       exit2:
256ecc9921SNikita Popov; CHECK-NEXT:    ret void
266ecc9921SNikita Popov;
276ecc9921SNikita Popoventry:
286ecc9921SNikita Popov  %n2 = add i32 %s, 123
296ecc9921SNikita Popov  br label %loop
306ecc9921SNikita Popov
316ecc9921SNikita Popovloop:
326ecc9921SNikita Popov  %i = phi i32 [ %s, %entry], [ %i.inc, %latch ]
336ecc9921SNikita Popov  %c1 = icmp eq i32 %i, %n2
346ecc9921SNikita Popov  br i1 %c1, label %exit1, label %latch
356ecc9921SNikita Popov
366ecc9921SNikita Popovlatch:
376ecc9921SNikita Popov  %c2 = icmp eq i32 %i, %n
386ecc9921SNikita Popov  %i.inc = add i32 %i, 1
396ecc9921SNikita Popov  br i1 %c2, label %exit2, label %loop
406ecc9921SNikita Popov
416ecc9921SNikita Popovexit1:
426ecc9921SNikita Popov  ret void
436ecc9921SNikita Popov
446ecc9921SNikita Popovexit2:
456ecc9921SNikita Popov  ret void
466ecc9921SNikita Popov}
47