[PATCH] D90977: [Coroutine] Move all used local allocas to the .resume function

[Xun Li via Phabricator via llvm-commits]

lxfind updated this revision to Diff 303562.
lxfind edited the summary of this revision.
lxfind added a comment.

update description


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D90977/new/

https://reviews.llvm.org/D90977

Files:
  llvm/lib/Transforms/Coroutines/CoroSplit.cpp
  llvm/test/Transforms/Coroutines/coro-alloca-05.ll


Index: llvm/test/Transforms/Coroutines/coro-alloca-05.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/Coroutines/coro-alloca-05.ll
@@ -0,0 +1,53 @@
+; Tests that allocas after coro.begin are properly that do not need to
+; live on the frame are properly moved to the .resume function.
+; RUN: opt < %s -coro-split -S | FileCheck %s
+; RUN: opt < %s -passes=coro-split -S | FileCheck %s
+
+define i8* @f() "coroutine.presplit"="1" {
+entry:
+  %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
+  %size = call i32 @llvm.coro.size.i32()
+  %alloc = call i8* @malloc(i32 %size)
+  %hdl = call i8* @llvm.coro.begin(token %id, i8* %alloc)
+  %x = alloca i32
+  %sp1 = call i8 @llvm.coro.suspend(token none, i1 false)
+  switch i8 %sp1, label %suspend [i8 0, label %resume
+  i8 1, label %cleanup]
+resume:
+  %x.value = load i32, i32* %x
+  call void @print(i32 %x.value)
+  br label %cleanup
+
+cleanup:
+  %mem = call i8* @llvm.coro.free(token %id, i8* %hdl)
+  call void @free(i8* %mem)
+  br label %suspend
+
+suspend:
+  call i1 @llvm.coro.end(i8* %hdl, i1 0)
+  ret i8* %hdl
+}
+
+; CHECK-LABEL: @f.resume(
+; CHECK-NEXT:  entry.resume:
+; CHECK-NEXT:    [[VFRAME:%.*]] = bitcast %f.Frame* [[FRAMEPTR:%.*]] to i8*
+; CHECK-NEXT:    [[X:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    [[X_VALUE:%.*]] = load i32, i32* [[X]], align 4
+; CHECK-NEXT:    call void @print(i32 [[X_VALUE]])
+; CHECK-NEXT:    call void @free(i8* [[VFRAME]])
+; CHECK-NEXT:    ret void
+
+declare i8* @llvm.coro.free(token, i8*)
+declare i32 @llvm.coro.size.i32()
+declare i8  @llvm.coro.suspend(token, i1)
+declare void @llvm.coro.resume(i8*)
+declare void @llvm.coro.destroy(i8*)
+
+declare token @llvm.coro.id(i32, i8*, i8*, i8*)
+declare i1 @llvm.coro.alloc(token)
+declare i8* @llvm.coro.begin(token, i8*)
+declare i1 @llvm.coro.end(i8*, i1)
+
+declare void @print(i32)
+declare noalias i8* @malloc(i32)
+declare void @free(i8*)
Index: llvm/lib/Transforms/Coroutines/CoroSplit.cpp
===================================================================
--- llvm/lib/Transforms/Coroutines/CoroSplit.cpp
+++ llvm/lib/Transforms/Coroutines/CoroSplit.cpp
@@ -581,15 +581,6 @@
   Builder.CreateUnreachable();
   BranchToEntry->eraseFromParent();
 
-  // Move any allocas into Entry that weren't moved into the frame.
-  for (auto IT = OldEntry->begin(), End = OldEntry->end(); IT != End;) {
-    Instruction &I = *IT++;
-    if (!isa<AllocaInst>(&I) || I.use_empty())
-      continue;
-
-    I.moveBefore(*Entry, Entry->getFirstInsertionPt());
-  }
-
   // Branch from the entry to the appropriate place.
   Builder.SetInsertPoint(Entry);
   switch (Shape.ABI) {
@@ -614,6 +605,19 @@
     break;
   }
   }
+
+  // Any alloca that's still being used but not reachable from the new entry
+  // needs to be moved to the new entry.
+  Function *F = OldEntry->getParent();
+  DominatorTree DT{*F};
+  for (auto IT = inst_begin(F), End = inst_end(F); IT != End;) {
+    Instruction &I = *IT++;
+    if (!isa<AllocaInst>(&I) || I.use_empty())
+      continue;
+    if (DT.isReachableFromEntry(I.getParent()))
+      continue;
+    I.moveBefore(*Entry, Entry->getFirstInsertionPt());
+  }
 }
 
 /// Derive the value of the new frame pointer.


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