[llvm] [LICM]The store instruction is prevented from (PR #69413)
via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 18 01:27:09 PDT 2023
https://github.com/XingYuShuai updated https://github.com/llvm/llvm-project/pull/69413
>From 3aee316069c62bfb5e8df4b4165ccaf6973ce2e2 Mon Sep 17 00:00:00 2001
From: XingYuShuai <1150775134 at qq.com>
Date: Mon, 16 Oct 2023 19:43:11 +0800
Subject: [PATCH] [LICM]The store instruction is prevented from being mentioned
outside the loop in some cases.
Please refer to issue:68776 for details.
Fixes llvm#68776
Fixes llvm#69279
---
llvm/lib/Transforms/Scalar/LICM.cpp | 32 +++++-
.../Transforms/LICM/signal-before-loop.ll | 108 ++++++++++++++++++
2 files changed, 139 insertions(+), 1 deletion(-)
create mode 100644 llvm/test/Transforms/LICM/signal-before-loop.ll
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index aab6b0538510891..4c5ba6680b30524 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -2050,11 +2050,41 @@ bool llvm::promoteLoopAccessesToScalars(
// We cannot (yet) promote a memory location that is loaded and stored in
// different sizes. While we are at it, collect alignment and AA info.
Type *AccessTy = nullptr;
+ const char *FunName = "signal";
for (Value *ASIV : PointerMustAliases) {
for (Use &U : ASIV->uses()) {
// Ignore instructions that are outside the loop.
Instruction *UI = dyn_cast<Instruction>(U.getUser());
- if (!UI || !CurLoop->contains(UI))
+ if (!UI)
+ continue;
+
+ if (StoreSafety == StoreSafe && !CurLoop->contains(UI)) {
+ if (LoadInst *NotCurLoopLoad = dyn_cast<LoadInst>(UI)) {
+ Function *NotCurLoopFun = UI->getParent()->getParent();
+ for (Use &UseFun : NotCurLoopFun->uses()) {
+ Instruction *UUseFun = dyn_cast<Instruction>(UseFun.getUser());
+ if (UUseFun) {
+ bool isSignal = false;
+ for (int i = 0; i < UUseFun->getNumOperands(); ++i) {
+ if (!strcmp(FunName, UUseFun->getOperand(i)->getName().data()))
+ isSignal = true;
+ }
+ if (!isSignal)
+ continue;
+ for (BasicBlock *BB = &CurLoop->getLoopPreheader()
+ ->getParent()
+ ->getEntryBlock();
+ BB != CurLoop->getLoopPreheader()->getNextNode();
+ BB = BB->getNextNode()) {
+ if (BB == UUseFun->getParent())
+ return false;
+ }
+ }
+ }
+ }
+ }
+
+ if (!CurLoop->contains(UI))
continue;
// If there is an non-load/store instruction in the loop, we can't promote
diff --git a/llvm/test/Transforms/LICM/signal-before-loop.ll b/llvm/test/Transforms/LICM/signal-before-loop.ll
new file mode 100644
index 000000000000000..79fbb3ff2cf5321
--- /dev/null
+++ b/llvm/test/Transforms/LICM/signal-before-loop.ll
@@ -0,0 +1,108 @@
+; RUN:opt -passes=licm -S < %s | FileCheck %s
+
+ at stderr = external local_unnamed_addr global ptr, align 8
+ at .str = private unnamed_addr constant [17 x i8] c"COUNT|%ld|1|lps\0A\00", align 1
+ at Run_Index = dso_local local_unnamed_addr global i64 0, align 8
+ at .str.1 = private unnamed_addr constant [20 x i8] c"Usage: %s duration\0A\00", align 1
+
+; Function Attrs: nounwind uwtable
+define dso_local void @wake_me(i32 noundef %seconds, ptr noundef %func) local_unnamed_addr #0 {
+entry:
+ %call = tail call ptr @signal(i32 noundef 14, ptr noundef %func) #7
+ %call1 = tail call i32 @alarm(i32 noundef %seconds) #7
+ ret void
+}
+
+; Function Attrs: nounwind
+declare ptr @signal(i32 noundef, ptr noundef) local_unnamed_addr #1
+
+; Function Attrs: nounwind
+declare i32 @alarm(i32 noundef) local_unnamed_addr #1
+
+; Function Attrs: noreturn nounwind uwtable
+define dso_local void @report() #2 {
+entry:
+ %0 = load ptr, ptr @stderr, align 8, !tbaa !6
+ %1 = load i64, ptr @Run_Index, align 8, !tbaa !10
+ %call = tail call i32 (ptr, ptr, ...) @fprintf(ptr noundef %0, ptr noundef nonnull @.str, i64 noundef %1) #8
+ tail call void @exit(i32 noundef 0) #9
+ unreachable
+}
+
+; Function Attrs: nofree nounwind
+declare noundef i32 @fprintf(ptr nocapture noundef, ptr nocapture noundef readonly, ...) local_unnamed_addr #3
+
+; Function Attrs: noreturn nounwind
+declare void @exit(i32 noundef) local_unnamed_addr #4
+
+; Function Attrs: noreturn nounwind uwtable
+define dso_local i32 @main(i32 noundef %argc, ptr nocapture noundef readonly %argv) local_unnamed_addr #2 {
+entry:
+ %cmp.not = icmp eq i32 %argc, 2
+ br i1 %cmp.not, label %if.end, label %if.then
+
+if.then: ; preds = %entry
+ %0 = load ptr, ptr @stderr, align 8, !tbaa !6
+ %1 = load ptr, ptr %argv, align 8, !tbaa !6
+ %call = tail call i32 (ptr, ptr, ...) @fprintf(ptr noundef %0, ptr noundef nonnull @.str.1, ptr noundef %1) #8
+ tail call void @exit(i32 noundef 1) #9
+ unreachable
+
+if.end: ; preds = %entry
+ %arrayidx1 = getelementptr inbounds ptr, ptr %argv, i64 1
+ %2 = load ptr, ptr %arrayidx1, align 8, !tbaa !6
+ %call.i = tail call i64 @strtol(ptr nocapture noundef nonnull %2, ptr noundef null, i32 noundef 10) #7
+ %conv.i = trunc i64 %call.i to i32
+ store i64 0, ptr @Run_Index, align 8, !tbaa !10
+ %call.i4 = tail call ptr @signal(i32 noundef 14, ptr noundef nonnull @report) #7
+ %call1.i = tail call i32 @alarm(i32 noundef %conv.i) #7
+ store i64 1, ptr @Run_Index, align 8, !tbaa !10
+ br label %for.cond
+
+; CHECK-LABEL: for.cond
+; CHECK: store
+for.cond: ; preds = %for.cond, %if.end
+ %3 = load i64, ptr @Run_Index, align 8, !tbaa !10
+ %inc = add i64 %3, 1
+ store i64 %inc, ptr @Run_Index, align 8, !tbaa !10
+ br label %for.cond
+}
+
+; Function Attrs: inlinehint mustprogress nofree nounwind readonly willreturn uwtable
+define available_externally i32 @atoi(ptr noundef nonnull %__nptr) local_unnamed_addr #5 {
+entry:
+ %call = tail call i64 @strtol(ptr nocapture noundef nonnull %__nptr, ptr noundef null, i32 noundef 10) #7
+ %conv = trunc i64 %call to i32
+ ret i32 %conv
+}
+
+; Function Attrs: mustprogress nofree nounwind willreturn
+declare i64 @strtol(ptr noundef readonly, ptr nocapture noundef, i32 noundef) local_unnamed_addr #6
+
+attributes #0 = { nounwind uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #1 = { nounwind "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #2 = { noreturn nounwind uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #3 = { nofree nounwind "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #4 = { noreturn nounwind "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #5 = { inlinehint mustprogress nofree nounwind readonly willreturn uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #6 = { mustprogress nofree nounwind willreturn "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+neon,+v8a" }
+attributes #7 = { nounwind }
+attributes #8 = { cold }
+attributes #9 = { noreturn nounwind }
+
+!llvm.module.flags = !{!0, !1, !2, !3, !4}
+!llvm.ident = !{!5}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 7, !"PIC Level", i32 2}
+!2 = !{i32 7, !"PIE Level", i32 2}
+!3 = !{i32 7, !"uwtable", i32 2}
+!4 = !{i32 7, !"frame-pointer", i32 1}
+!5 = !{!"Huawei BiSheng Compiler clang version 15.0.4 (b1a488d0a16f)"}
+!6 = !{!7, !7, i64 0}
+!7 = !{!"any pointer", !8, i64 0}
+!8 = !{!"omnipotent char", !9, i64 0}
+!9 = !{!"Simple C/C++ TBAA"}
+!10 = !{!11, !11, i64 0}
+!11 = !{!"long", !8, i64 0}
+
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