[llvm] 7688027 - [Test] Add tests showing that IndVars cannot prove (X + 1 > X)
Max Kazantsev via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 17 08:38:04 PDT 2020
Author: Max Kazantsev
Date: 2020-09-17T22:37:43+07:00
New Revision: 7688027f166311164982bb15fe44041f31b6d45f
URL: https://github.com/llvm/llvm-project/commit/7688027f166311164982bb15fe44041f31b6d45f
DIFF: https://github.com/llvm/llvm-project/commit/7688027f166311164982bb15fe44041f31b6d45f.diff
LOG: [Test] Add tests showing that IndVars cannot prove (X + 1 > X)
Added:
llvm/test/Transforms/IndVarSimplify/trivial-checks.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Transforms/IndVarSimplify/trivial-checks.ll b/llvm/test/Transforms/IndVarSimplify/trivial-checks.ll
new file mode 100644
index 000000000000..a6fe59a6b223
--- /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
+}
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