[Tests] Add cases where we're failing to discharge provably loop exits (tests for D63733)

llvm-svn: 364220

1 files changed, 193 insertions, 0 deletions

diff --git a/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll b/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll
new file mode 100644
index 00000000000..da3eb5ef976
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/eliminate-exit.ll
@@ -0,0 +1,193 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -indvars -S < %s | FileCheck %s
+
+define void @ult(i64 %n, i64 %m) {
+; CHECK-LABEL: @ult(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP0:%.*]] = icmp ult i64 [[N:%.*]], [[M:%.*]]
+; CHECK-NEXT:    br i1 [[CMP0]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[LATCH:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       latch:
+; CHECK-NEXT:    call void @side_effect()
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[IV]], [[M]]
+; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP]], label [[EXIT_LOOPEXIT]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp0 = icmp ult i64 %n, %m
+  br i1 %cmp0, label %loop, label %exit
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %latch ]
+  %iv.next = add i64 %iv, 1
+  %cmp1 = icmp ult i64 %iv, %n
+  br i1 %cmp1, label %latch, label %exit
+latch:
+  call void @side_effect()
+  %cmp2 = icmp ult i64 %iv, %m
+  br i1 %cmp2, label %loop, label %exit
+exit:
+  ret void
+}
+
+define void @ugt(i64 %n, i64 %m) {
+; CHECK-LABEL: @ugt(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP0:%.*]] = icmp ugt i64 [[N:%.*]], [[M:%.*]]
+; CHECK-NEXT:    br i1 [[CMP0]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[LATCH:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       latch:
+; CHECK-NEXT:    call void @side_effect()
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[IV]], [[M]]
+; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP]], label [[EXIT_LOOPEXIT]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp0 = icmp ugt i64 %n, %m
+  br i1 %cmp0, label %loop, label %exit
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %latch ]
+  %iv.next = add i64 %iv, 1
+  %cmp1 = icmp ult i64 %iv, %n
+  br i1 %cmp1, label %latch, label %exit
+latch:
+  call void @side_effect()
+  %cmp2 = icmp ult i64 %iv, %m
+  br i1 %cmp2, label %loop, label %exit
+exit:
+  ret void
+}
+
+define void @ule(i64 %n, i64 %m) {
+; CHECK-LABEL: @ule(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP0:%.*]] = icmp ule i64 [[N:%.*]], [[M:%.*]]
+; CHECK-NEXT:    br i1 [[CMP0]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[LATCH:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       latch:
+; CHECK-NEXT:    call void @side_effect()
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[IV]], [[M]]
+; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP]], label [[EXIT_LOOPEXIT]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp0 = icmp ule i64 %n, %m
+  br i1 %cmp0, label %loop, label %exit
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %latch ]
+  %iv.next = add i64 %iv, 1
+  %cmp1 = icmp ult i64 %iv, %n
+  br i1 %cmp1, label %latch, label %exit
+latch:
+  call void @side_effect()
+  %cmp2 = icmp ult i64 %iv, %m
+  br i1 %cmp2, label %loop, label %exit
+exit:
+  ret void
+}
+
+define void @uge(i64 %n, i64 %m) {
+; CHECK-LABEL: @uge(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP0:%.*]] = icmp uge i64 [[N:%.*]], [[M:%.*]]
+; CHECK-NEXT:    br i1 [[CMP0]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[LATCH:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add i64 [[IV]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       latch:
+; CHECK-NEXT:    call void @side_effect()
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[IV]], [[M]]
+; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP]], label [[EXIT_LOOPEXIT]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp0 = icmp uge i64 %n, %m
+  br i1 %cmp0, label %loop, label %exit
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %latch ]
+  %iv.next = add i64 %iv, 1
+  %cmp1 = icmp ult i64 %iv, %n
+  br i1 %cmp1, label %latch, label %exit
+latch:
+  call void @side_effect()
+  %cmp2 = icmp ult i64 %iv, %m
+  br i1 %cmp2, label %loop, label %exit
+exit:
+  ret void
+}
+
+
+define void @ult_const_max(i64 %n) {
+; CHECK-LABEL: @ult_const_max(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP0:%.*]] = icmp ult i64 [[N:%.*]], 20
+; CHECK-NEXT:    br i1 [[CMP0]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[LATCH:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
+; CHECK-NEXT:    [[UDIV:%.*]] = udiv i64 [[IV]], 10
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[UDIV]], 2
+; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       latch:
+; CHECK-NEXT:    call void @side_effect()
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[IV]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP]], label [[EXIT_LOOPEXIT]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp0 = icmp ult i64 %n, 20
+  br i1 %cmp0, label %loop, label %exit
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %latch ]
+  %iv.next = add i64 %iv, 1
+  %udiv = udiv i64 %iv, 10
+  %cmp1 = icmp ult i64 %udiv, 2
+  br i1 %cmp1, label %latch, label %exit
+latch:
+  call void @side_effect()
+  %cmp2 = icmp ult i64 %iv, %n
+  br i1 %cmp2, label %loop, label %exit
+exit:
+  ret void
+}
+
+
+declare void @side_effect()