From: Max Kazantsev <mkazantsev@azul.com>
Date: Thu, 17 Sep 2020 15:36:41 +0000 (+0700)
Subject: [Test] Add tests showing that IndVars cannot prove (X + 1 > X)
X-Git-Tag: llvmorg-13-init~11718
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7688027f166311164982bb15fe44041f31b6d45f;p=platform%2Fupstream%2Fllvm.git

[Test] Add tests showing that IndVars cannot prove (X + 1 > X)
---

diff --git a/llvm/test/Transforms/IndVarSimplify/trivial-checks.ll b/llvm/test/Transforms/IndVarSimplify/trivial-checks.ll
new file mode 100644
index 0000000..a6fe59a
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/trivial-checks.ll
@@ -0,0 +1,186 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -indvars -S < %s | FileCheck %s
+; RUN: opt -passes=indvars -S < %s | FileCheck %s
+
+; FIXME: In all cases, x is from [0; 1000) and we cannot prove that x + 1 > x.
+
+define void @test_sgt(i32 %x) {
+; CHECK-LABEL: @test_sgt(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PRECONDITION:%.*]] = icmp ult i32 [[X:%.*]], 1000
+; CHECK-NEXT:    br i1 [[PRECONDITION]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[GUARDED:%.*]] ], [ [[X]], [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[TMP:%.*]] = add i32 [[IV]], 1
+; CHECK-NEXT:    [[GUARD:%.*]] = icmp sgt i32 [[TMP]], [[IV]]
+; CHECK-NEXT:    br i1 [[GUARD]], label [[GUARDED]], label [[FAIL:%.*]]
+; CHECK:       guarded:
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
+; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[IV]], 0
+; CHECK-NEXT:    br i1 [[COND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+; CHECK:       fail:
+; CHECK-NEXT:    unreachable
+;
+entry:
+  %precondition = icmp ult i32 %x, 1000
+  br i1 %precondition, label %loop, label %exit
+
+loop:
+  %iv = phi i32 [%x, %entry], [%iv.next, %guarded]
+  %tmp = add i32 %iv, 1
+  %guard = icmp sgt i32 %tmp, %iv
+  br i1 %guard, label %guarded, label %fail
+
+guarded:
+  %iv.next = add i32 %iv, -1
+  %cond = icmp eq i32 %iv, 0
+  br i1 %cond, label %loop, label %exit
+
+exit:
+  ret void
+
+fail:
+  unreachable
+}
+
+define void @test_sge(i32 %x) {
+; CHECK-LABEL: @test_sge(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PRECONDITION:%.*]] = icmp ult i32 [[X:%.*]], 1000
+; CHECK-NEXT:    br i1 [[PRECONDITION]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[GUARDED:%.*]] ], [ [[X]], [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[TMP:%.*]] = add i32 [[IV]], 1
+; CHECK-NEXT:    [[GUARD:%.*]] = icmp sge i32 [[TMP]], [[IV]]
+; CHECK-NEXT:    br i1 [[GUARD]], label [[GUARDED]], label [[FAIL:%.*]]
+; CHECK:       guarded:
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
+; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[IV]], 0
+; CHECK-NEXT:    br i1 [[COND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+; CHECK:       fail:
+; CHECK-NEXT:    unreachable
+;
+entry:
+  %precondition = icmp ult i32 %x, 1000
+  br i1 %precondition, label %loop, label %exit
+
+loop:
+  %iv = phi i32 [%x, %entry], [%iv.next, %guarded]
+  %tmp = add i32 %iv, 1
+  %guard = icmp sge i32 %tmp, %iv
+  br i1 %guard, label %guarded, label %fail
+
+guarded:
+  %iv.next = add i32 %iv, -1
+  %cond = icmp eq i32 %iv, 0
+  br i1 %cond, label %loop, label %exit
+
+exit:
+  ret void
+
+fail:
+  unreachable
+}
+
+define void @test_ugt(i32 %x) {
+; CHECK-LABEL: @test_ugt(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PRECONDITION:%.*]] = icmp ult i32 [[X:%.*]], 1000
+; CHECK-NEXT:    br i1 [[PRECONDITION]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[GUARDED:%.*]] ], [ [[X]], [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[TMP:%.*]] = add i32 [[IV]], 1
+; CHECK-NEXT:    [[GUARD:%.*]] = icmp ugt i32 [[TMP]], [[IV]]
+; CHECK-NEXT:    br i1 [[GUARD]], label [[GUARDED]], label [[FAIL:%.*]]
+; CHECK:       guarded:
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
+; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[IV]], 0
+; CHECK-NEXT:    br i1 [[COND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+; CHECK:       fail:
+; CHECK-NEXT:    unreachable
+;
+entry:
+  %precondition = icmp ult i32 %x, 1000
+  br i1 %precondition, label %loop, label %exit
+
+loop:
+  %iv = phi i32 [%x, %entry], [%iv.next, %guarded]
+  %tmp = add i32 %iv, 1
+  %guard = icmp ugt i32 %tmp, %iv
+  br i1 %guard, label %guarded, label %fail
+
+guarded:
+  %iv.next = add i32 %iv, -1
+  %cond = icmp eq i32 %iv, 0
+  br i1 %cond, label %loop, label %exit
+
+exit:
+  ret void
+
+fail:
+  unreachable
+}
+
+
+define void @test_uge(i32 %x) {
+; CHECK-LABEL: @test_uge(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PRECONDITION:%.*]] = icmp ult i32 [[X:%.*]], 1000
+; CHECK-NEXT:    br i1 [[PRECONDITION]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
+; CHECK:       loop.preheader:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[GUARDED:%.*]] ], [ [[X]], [[LOOP_PREHEADER]] ]
+; CHECK-NEXT:    [[TMP:%.*]] = add i32 [[IV]], 1
+; CHECK-NEXT:    [[GUARD:%.*]] = icmp uge i32 [[TMP]], [[IV]]
+; CHECK-NEXT:    br i1 [[GUARD]], label [[GUARDED]], label [[FAIL:%.*]]
+; CHECK:       guarded:
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
+; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[IV]], 0
+; CHECK-NEXT:    br i1 [[COND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+; CHECK:       fail:
+; CHECK-NEXT:    unreachable
+;
+entry:
+  %precondition = icmp ult i32 %x, 1000
+  br i1 %precondition, label %loop, label %exit
+
+loop:
+  %iv = phi i32 [%x, %entry], [%iv.next, %guarded]
+  %tmp = add i32 %iv, 1
+  %guard = icmp uge i32 %tmp, %iv
+  br i1 %guard, label %guarded, label %fail
+
+guarded:
+  %iv.next = add i32 %iv, -1
+  %cond = icmp eq i32 %iv, 0
+  br i1 %cond, label %loop, label %exit
+
+exit:
+  ret void
+
+fail:
+  unreachable
+}