[llvm] [JumpThreading] Invalidate LVI after `combineMetadataForCSE`. (PR #65219)

[via llvm-commits]

https://github.com/DianQK created https://github.com/llvm/llvm-project/pull/65219:

Fixes #65195.

LVI information may be out of date after `combineMetadataForCSE`.

>From 543fd1854da4ee918c50e9ac87e49cf4df4534a9 Mon Sep 17 00:00:00 2001
From: DianQK <dianqk at dianqk.net>
Date: Sun, 3 Sep 2023 12:18:57 +0800
Subject: [PATCH 1/2] [JumpThreading][NFC] Pre-commit for invalid LVI.

---
 .../JumpThreading/invalidate-lvi.ll           | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 llvm/test/Transforms/JumpThreading/invalidate-lvi.ll

diff --git a/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll b/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll
new file mode 100644
index 000000000000000..9c5cbfac62d9fb5
--- /dev/null
+++ b/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll
@@ -0,0 +1,53 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 3
+; RUN: opt -S -passes=jump-threading < %s | FileCheck %s
+
+declare void @set_value(ptr)
+
+declare void @bar()
+
+define void @foo(i1 %0) {
+; CHECK-LABEL: define void @foo(
+; CHECK-SAME: i1 [[TMP0:%.*]]) {
+; CHECK-NEXT:  start:
+; CHECK-NEXT:    [[V:%.*]] = alloca i64, align 8
+; CHECK-NEXT:    call void @set_value(ptr [[V]])
+; CHECK-NEXT:    [[L1:%.*]] = load i64, ptr [[V]], align 8
+; CHECK-NEXT:    br i1 [[TMP0]], label [[BB0:%.*]], label [[BB4:%.*]]
+; CHECK:       bb0:
+; CHECK-NEXT:    [[C1:%.*]] = icmp eq i64 [[L1]], 0
+; CHECK-NEXT:    br i1 [[C1]], label [[BB1:%.*]], label [[BB4]]
+; CHECK:       bb1:
+; CHECK-NEXT:    store i64 0, ptr [[V]], align 8
+; CHECK-NEXT:    br label [[BB4]]
+; CHECK:       bb4:
+; CHECK-NEXT:    [[L2:%.*]] = phi i64 [ 0, [[BB1]] ], [ [[L1]], [[BB0]] ], [ [[L1]], [[START:%.*]] ]
+; CHECK-NEXT:    ret void
+;
+start:
+  %v = alloca i64, align 8
+  call void @set_value(ptr %v)
+  %l1 = load i64, ptr %v, align 8, !range !0
+  br i1 %0, label %bb0, label %bb2
+
+bb0:                                              ; preds = %start
+  %c1 = icmp eq i64 %l1, 0
+  br i1 %c1, label %bb1, label %bb2
+
+bb1:                                              ; preds = %bb0
+  store i64 0, ptr %v, align 8
+  br label %bb2
+
+bb2:                                              ; preds = %bb1, %bb0, %start
+  %l2 = load i64, ptr %v, align 8
+  %1 = icmp eq i64 %l2, 2
+  br i1 %1, label %bb3, label %bb4
+
+bb3:                                              ; preds = %bb2
+  call void @bar()
+  ret void
+
+bb4:                                              ; preds = %bb2
+  ret void
+}
+
+!0 = !{i64 0, i64 2}

>From 1eca78a450850aeea9f858296b3e90ca5325b982 Mon Sep 17 00:00:00 2001
From: DianQK <dianqk at dianqk.net>
Date: Sun, 3 Sep 2023 12:23:33 +0800
Subject: [PATCH 2/2] [JumpThreading] Invalidate LVI after
 `combineMetadataForCSE`.

---
 llvm/lib/Transforms/Scalar/JumpThreading.cpp     |  2 ++
 .../Transforms/JumpThreading/invalidate-lvi.ll   | 16 +++++++++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 180e6b4c8238809..3e0049c66c1503c 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -1269,6 +1269,7 @@ bool JumpThreadingPass::simplifyPartiallyRedundantLoad(LoadInst *LoadI) {
     if (IsLoadCSE) {
       LoadInst *NLoadI = cast<LoadInst>(AvailableVal);
       combineMetadataForCSE(NLoadI, LoadI, false);
+      LVI->eraseBlock(NLoadI->getParent());
     };
 
     // If the returned value is the load itself, replace with poison. This can
@@ -1461,6 +1462,7 @@ bool JumpThreadingPass::simplifyPartiallyRedundantLoad(LoadInst *LoadI) {
 
   for (LoadInst *PredLoadI : CSELoads) {
     combineMetadataForCSE(PredLoadI, LoadI, true);
+    LVI->eraseBlock(PredLoadI->getParent());
   }
 
   LoadI->replaceAllUsesWith(PN);
diff --git a/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll b/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll
index 9c5cbfac62d9fb5..27191d6f54c2d8c 100644
--- a/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll
+++ b/llvm/test/Transforms/JumpThreading/invalidate-lvi.ll
@@ -12,15 +12,21 @@ define void @foo(i1 %0) {
 ; CHECK-NEXT:    [[V:%.*]] = alloca i64, align 8
 ; CHECK-NEXT:    call void @set_value(ptr [[V]])
 ; CHECK-NEXT:    [[L1:%.*]] = load i64, ptr [[V]], align 8
-; CHECK-NEXT:    br i1 [[TMP0]], label [[BB0:%.*]], label [[BB4:%.*]]
+; CHECK-NEXT:    br i1 [[TMP0]], label [[BB0:%.*]], label [[BB2:%.*]]
 ; CHECK:       bb0:
 ; CHECK-NEXT:    [[C1:%.*]] = icmp eq i64 [[L1]], 0
-; CHECK-NEXT:    br i1 [[C1]], label [[BB1:%.*]], label [[BB4]]
-; CHECK:       bb1:
+; CHECK-NEXT:    br i1 [[C1]], label [[BB2_THREAD:%.*]], label [[BB2]]
+; CHECK:       bb2.thread:
 ; CHECK-NEXT:    store i64 0, ptr [[V]], align 8
-; CHECK-NEXT:    br label [[BB4]]
+; CHECK-NEXT:    br label [[BB4:%.*]]
+; CHECK:       bb2:
+; CHECK-NEXT:    [[L2:%.*]] = phi i64 [ [[L1]], [[BB0]] ], [ [[L1]], [[START:%.*]] ]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i64 [[L2]], 2
+; CHECK-NEXT:    br i1 [[TMP1]], label [[BB3:%.*]], label [[BB4]]
+; CHECK:       bb3:
+; CHECK-NEXT:    call void @bar()
+; CHECK-NEXT:    ret void
 ; CHECK:       bb4:
-; CHECK-NEXT:    [[L2:%.*]] = phi i64 [ 0, [[BB1]] ], [ [[L1]], [[BB0]] ], [ [[L1]], [[START:%.*]] ]
 ; CHECK-NEXT:    ret void
 ;
 start: