[AssumeBundles] preserve information in LICM

[jdoerfert]

LGTM.

llvm/lib/Transforms/Scalar/LICM.cpp

 //===-- LICM.cpp - Loop Invariant Code Motion Pass ------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //

 #include "llvm/IR/PatternMatch.h"
 #include "llvm/IR/PredIteratorCache.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Scalar/LoopPassManager.h"
+#include "llvm/Transforms/Utils/AssumeBundleBuilder.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/SSAUpdater.h"
 #include <algorithm>
 #include <utility>
 using namespace llvm;
 
for (DomTreeNode *DTN : reverse(Worklist)) {
 
     for (BasicBlock::iterator II = BB->end(); II != BB->begin();) {
       Instruction &I = *--II;
 
       // If the instruction is dead, we would try to sink it because it isn't
       // used in the loop, instead, just delete it.
       if (isInstructionTriviallyDead(&I, TLI)) {
         LLVM_DEBUG(dbgs() << "LICM deleting dead inst: " << I << '\n');
+        salvageKnowledge(&I);
         salvageDebugInfo(I);
         ++II;
         eraseInstruction(I, *SafetyInfo, CurAST, MSSAU);
         Changed = true;
         continue;
       }
 
       // Check to see if we can sink this instruction to the exit blocks

llvm/test/Transforms/LICM/pr23608.ll

-; RUN: opt -S -licm %s | FileCheck %s
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -licm %s | FileCheck %s --check-prefixes=CHECK,NO_ASSUME
+; RUN: opt -S -licm --enable-knowledge-retention %s | FileCheck %s --check-prefixes=CHECK,USE_ASSUME
 ; ModuleID = '../pr23608.ll'
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 %struct.PyFrameObject = type { i32 }
 
 @a = common global %struct.PyFrameObject* null, align 8
 @__msan_origin_tls = external thread_local(initialexec) global i32
 
 define void @fn1() {
+; NO_ASSUME-LABEL: @fn1(
+; NO_ASSUME-NEXT:  entry:
+; NO_ASSUME-NEXT:    br label [[INDIRECTGOTO:%.*]]
+; NO_ASSUME:       while.cond:
+; NO_ASSUME-NEXT:    [[TMP:%.*]] = load %struct.PyFrameObject*, %struct.PyFrameObject** @a, align 8
+; NO_ASSUME-NEXT:    [[F_IBLOCK:%.*]] = getelementptr inbounds [[STRUCT_PYFRAMEOBJECT:%.*]], %struct.PyFrameObject* [[TMP]], i64 0, i32 0
+; NO_ASSUME-NEXT:    br label [[BB2:%.*]]
+; NO_ASSUME:       bb:
+; NO_ASSUME-NEXT:    call void @__msan_warning_noreturn()
+; NO_ASSUME-NEXT:    unreachable
+; NO_ASSUME:       bb2:
+; NO_ASSUME-NEXT:    [[TMP4:%.*]] = ptrtoint i32* [[F_IBLOCK]] to i64
+; NO_ASSUME-NEXT:    [[TOBOOL:%.*]] = icmp eq i64 [[TMP4]], 0
+; NO_ASSUME-NEXT:    br i1 [[TOBOOL]], label [[BB13:%.*]], label [[BB15:%.*]]
+; NO_ASSUME:       bb13:
+; NO_ASSUME-NEXT:    [[F_IBLOCK_LCSSA:%.*]] = phi i32* [ [[F_IBLOCK]], [[BB2]] ]
+; NO_ASSUME-NEXT:    [[TMP4_LE:%.*]] = ptrtoint i32* [[F_IBLOCK_LCSSA]] to i64
+; NO_ASSUME-NEXT:    [[TMP8_LE:%.*]] = inttoptr i64 [[TMP4_LE]] to i32*
+; NO_ASSUME-NEXT:    call void @__msan_warning_noreturn()
+; NO_ASSUME-NEXT:    unreachable
+; NO_ASSUME:       bb15:
+; NO_ASSUME-NEXT:    br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND:%.*]]
+; NO_ASSUME:       while.end:
+; NO_ASSUME-NEXT:    ret void
+; NO_ASSUME:       indirectgoto:
+; NO_ASSUME-NEXT:    indirectbr i8* null, [label [[INDIRECTGOTO]], label %while.cond]
+;
+; USE_ASSUME-LABEL: @fn1(
+; USE_ASSUME-NEXT:  entry:
+; USE_ASSUME-NEXT:    br label [[INDIRECTGOTO:%.*]]
+; USE_ASSUME:       while.cond:
+; USE_ASSUME-NEXT:    [[TMP:%.*]] = load %struct.PyFrameObject*, %struct.PyFrameObject** @a, align 8
+; USE_ASSUME-NEXT:    call void @llvm.assume(i1 true) [ "align"(i64* inttoptr (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665) to i64*), i64 8), "dereferenceable"(i64* inttoptr (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665) to i64*), i64 8), "nonnull"(i64* inttoptr (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665) to i64*)) ]
+; USE_ASSUME-NEXT:    call void @llvm.assume(i1 true) [ "align"(i32* inttoptr (i64 add (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665), i64 35184372088832) to i32*), i64 8), "dereferenceable"(i32* inttoptr (i64 add (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665), i64 35184372088832) to i32*), i64 4), "nonnull"(i32* inttoptr (i64 add (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665), i64 35184372088832) to i32*)) ]
+; USE_ASSUME-NEXT:    [[F_IBLOCK:%.*]] = getelementptr inbounds [[STRUCT_PYFRAMEOBJECT:%.*]], %struct.PyFrameObject* [[TMP]], i64 0, i32 0
+; USE_ASSUME-NEXT:    br label [[BB2:%.*]]
+; USE_ASSUME:       bb:
+; USE_ASSUME-NEXT:    call void @__msan_warning_noreturn()
+; USE_ASSUME-NEXT:    unreachable
+; USE_ASSUME:       bb2:
+; USE_ASSUME-NEXT:    call void @llvm.assume(i1 true) [ "align"(i32* [[F_IBLOCK]], i64 4), "dereferenceable"(i32* [[F_IBLOCK]], i64 4), "nonnull"(i32* [[F_IBLOCK]]) ]
+; USE_ASSUME-NEXT:    [[TMP4:%.*]] = ptrtoint i32* [[F_IBLOCK]] to i64
+; USE_ASSUME-NEXT:    [[TOBOOL:%.*]] = icmp eq i64 [[TMP4]], 0
+; USE_ASSUME-NEXT:    br i1 [[TOBOOL]], label [[BB13:%.*]], label [[BB15:%.*]]
+; USE_ASSUME:       bb13:
+; USE_ASSUME-NEXT:    [[F_IBLOCK_LCSSA:%.*]] = phi i32* [ [[F_IBLOCK]], [[BB2]] ]
+; USE_ASSUME-NEXT:    [[TMP4_LE:%.*]] = ptrtoint i32* [[F_IBLOCK_LCSSA]] to i64
+; USE_ASSUME-NEXT:    [[TMP8_LE:%.*]] = inttoptr i64 [[TMP4_LE]] to i32*
+; USE_ASSUME-NEXT:    call void @__msan_warning_noreturn()
+; USE_ASSUME-NEXT:    unreachable
+; USE_ASSUME:       bb15:
+; USE_ASSUME-NEXT:    br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND:%.*]]
+; USE_ASSUME:       while.end:
+; USE_ASSUME-NEXT:    ret void
+; USE_ASSUME:       indirectgoto:
+; USE_ASSUME-NEXT:    indirectbr i8* null, [label [[INDIRECTGOTO]], label %while.cond]
+;
 entry:
   br label %indirectgoto
 
 while.cond:                                       ; preds = %indirectgoto, %bb15
   %tmp = load %struct.PyFrameObject*, %struct.PyFrameObject** @a, align 8
   %_msld = load i64, i64* inttoptr (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665) to i64*), align 8
   %tmp1 = load i32, i32* inttoptr (i64 add (i64 and (i64 ptrtoint (%struct.PyFrameObject** @a to i64), i64 -70368744177665), i64 35184372088832) to i32*), align 8
   %f_iblock = getelementptr inbounds %struct.PyFrameObject, %struct.PyFrameObject* %tmp, i64 0, i32 0
   br label %bb2
 
 bb:                                               ; preds = %while.cond
   call void @__msan_warning_noreturn()
   unreachable
 
 bb2:                                              ; preds = %while.cond
   %tmp3 = load i32, i32* %f_iblock, align 4
   %tmp4 = ptrtoint i32* %f_iblock to i64
   %tmp8 = inttoptr i64 %tmp4 to i32*
   %tobool = icmp eq i64 %tmp4, 0
   br i1 %tobool, label %bb13, label %bb15
 
 bb13:                                             ; preds = %bb2
-; CHECK-LABEL: bb13:
-; CHECK: %tmp8.le = inttoptr
   %.lcssa7 = phi i32* [ %tmp8, %bb2 ]
   call void @__msan_warning_noreturn()
   unreachable
 
 bb15:                                             ; preds = %bb2
   br i1 %tobool, label %while.end, label %while.cond
 
 while.end:                                        ; preds = %bb15
   ret void
 
 indirectgoto:                                     ; preds = %indirectgoto, %entry
   indirectbr i8* null, [label %indirectgoto, label %while.cond]
 }
 
 declare void @__msan_warning_noreturn()