[llvm] 159f9a6 - [Test] Add test showing some simple cases that IndVarSimplify does not cover
Max Kazantsev via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 3 04:35:42 PDT 2020
Author: Max Kazantsev
Date: 2020-09-03T18:35:26+07:00
New Revision: 159f9a69b4bb4ee36a69c0dcb276fb2b533cbda2
URL: https://github.com/llvm/llvm-project/commit/159f9a69b4bb4ee36a69c0dcb276fb2b533cbda2
DIFF: https://github.com/llvm/llvm-project/commit/159f9a69b4bb4ee36a69c0dcb276fb2b533cbda2.diff
LOG: [Test] Add test showing some simple cases that IndVarSimplify does not cover
Added:
llvm/test/Transforms/IndVarSimplify/monotonic_checks.ll
Modified:
Removed:
################################################################################
diff --git a/llvm/test/Transforms/IndVarSimplify/monotonic_checks.ll b/llvm/test/Transforms/IndVarSimplify/monotonic_checks.ll
new file mode 100644
index 000000000000..6a9713410200
--- /dev/null
+++ b/llvm/test/Transforms/IndVarSimplify/monotonic_checks.ll
@@ -0,0 +1,169 @@
+; 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
+
+; Monotonic decrementing iv. we should be able to prove that %iv.next <s len
+; basing on its nsw and the fact that its starting value <s len.
+define i32 @test_01(i32* %p) {
+; CHECK-LABEL: @test_01(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[P:%.*]], align 4, [[RNG0:!range !.*]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[LEN]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[IV_NEXT]] = add nsw i32 [[IV]], -1
+; CHECK-NEXT: [[RC:%.*]] = icmp slt i32 [[IV_NEXT]], [[LEN]]
+; CHECK-NEXT: br i1 [[RC]], label [[BACKEDGE]], label [[FAIL:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[IV]], 0
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: fail:
+; CHECK-NEXT: ret i32 -1
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+entry:
+ %len = load i32, i32* %p, !range !0
+ br label %loop
+
+loop:
+ %iv = phi i32 [%len, %entry], [%iv.next, %backedge]
+ %iv.next = add i32 %iv, -1
+ %rc = icmp slt i32 %iv.next, %len
+ br i1 %rc, label %backedge, label %fail
+
+backedge:
+ %loop.cond = icmp ne i32 %iv, 0
+ br i1 %loop.cond, label %loop, label %exit
+
+fail:
+ ret i32 -1
+
+exit:
+ ret i32 0
+}
+
+; We should not remove this range check because signed overflow is possible here (start at len = 0).
+define i32 @test_01_neg(i32* %p) {
+; CHECK-LABEL: @test_01_neg(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[P:%.*]], align 4, [[RNG0]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[LEN]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], -1
+; CHECK-NEXT: [[RC:%.*]] = icmp slt i32 [[IV_NEXT]], [[LEN]]
+; CHECK-NEXT: br i1 [[RC]], label [[BACKEDGE]], label [[FAIL:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[IV]], 1
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: fail:
+; CHECK-NEXT: ret i32 -1
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+entry:
+ %len = load i32, i32* %p, !range !0
+ br label %loop
+
+loop:
+ %iv = phi i32 [%len, %entry], [%iv.next, %backedge]
+ %iv.next = add i32 %iv, -1
+ %rc = icmp slt i32 %iv.next, %len
+ br i1 %rc, label %backedge, label %fail
+
+backedge:
+ %loop.cond = icmp ne i32 %iv, 1
+ br i1 %loop.cond, label %loop, label %exit
+
+fail:
+ ret i32 -1
+
+exit:
+ ret i32 0
+}
+
+; Monotonic incrementing iv. we should be able to prove that %iv.next <s len
+; basing on its nsw and the fact that its starting value <s len.
+define i32 @test_02(i32* %p) {
+; CHECK-LABEL: @test_02(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[P:%.*]], align 4, [[RNG1:!range !.*]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[LEN]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[IV_NEXT]] = add nsw i32 [[IV]], 1
+; CHECK-NEXT: [[RC:%.*]] = icmp sgt i32 [[IV_NEXT]], [[LEN]]
+; CHECK-NEXT: br i1 [[RC]], label [[BACKEDGE]], label [[FAIL:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[IV]], 0
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: fail:
+; CHECK-NEXT: ret i32 -1
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+entry:
+ %len = load i32, i32* %p, !range !1
+ br label %loop
+
+loop:
+ %iv = phi i32 [%len, %entry], [%iv.next, %backedge]
+ %iv.next = add i32 %iv, 1
+ %rc = icmp sgt i32 %iv.next, %len
+ br i1 %rc, label %backedge, label %fail
+
+backedge:
+ %loop.cond = icmp ne i32 %iv, 0
+ br i1 %loop.cond, label %loop, label %exit
+
+fail:
+ ret i32 -1
+
+exit:
+ ret i32 0
+}
+
+; We should not remove this range check because signed overflow is possible here (start at len = -1).
+define i32 @test_02_neg(i32* %p) {
+; CHECK-LABEL: @test_02_neg(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[LEN:%.*]] = load i32, i32* [[P:%.*]], align 4, [[RNG1]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[LEN]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT: [[RC:%.*]] = icmp sgt i32 [[IV_NEXT]], [[LEN]]
+; CHECK-NEXT: br i1 [[RC]], label [[BACKEDGE]], label [[FAIL:%.*]]
+; CHECK: backedge:
+; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[IV]], -2
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK: fail:
+; CHECK-NEXT: ret i32 -1
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+;
+entry:
+ %len = load i32, i32* %p, !range !1
+ br label %loop
+
+loop:
+ %iv = phi i32 [%len, %entry], [%iv.next, %backedge]
+ %iv.next = add i32 %iv, 1
+ %rc = icmp sgt i32 %iv.next, %len
+ br i1 %rc, label %backedge, label %fail
+
+backedge:
+ %loop.cond = icmp ne i32 %iv, -2
+ br i1 %loop.cond, label %loop, label %exit
+
+fail:
+ ret i32 -1
+
+exit:
+ ret i32 0
+}
+
+
+!0 = !{i32 0, i32 2147483647}
+!1 = !{i32 -2147483648, i32 -1}
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