[Coroutines] Part12: Handle alloca address-taken

Summary:
Move early uses of spilled variables after CoroBegin.

For example, if a parameter had address taken, we may end up with the code
like:
        define @f(i32 %n) {
          %n.addr = alloca i32
          store %n, %n.addr
          ...
          call @coro.begin

This patch fixes the problem by moving uses of spilled variables after CoroBegin.

Reviewers: majnemer

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24234

llvm-svn: 280678

1 files changed, 67 insertions, 0 deletions

diff --git a/llvm/test/Transforms/Coroutines/ArgAddr.ll b/llvm/test/Transforms/Coroutines/ArgAddr.ll
new file mode 100644
index 00000000000..4bedb510cd9
--- /dev/null
+++ b/llvm/test/Transforms/Coroutines/ArgAddr.ll
@@ -0,0 +1,67 @@
+; Need to move users of allocas that were moved into the coroutine frame after
+; coro.begin.
+; RUN: opt < %s -O2 -enable-coroutines -S | FileCheck %s
+
+define nonnull i8* @f(i32 %n) {
+entry:
+  %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null);
+  %n.addr = alloca i32
+  store i32 %n, i32* %n.addr ; this needs to go after coro.begin
+  %0 = tail call i32 @llvm.coro.size.i32()
+  %call = tail call i8* @malloc(i32 %0)
+  %1 = tail call noalias nonnull i8* @llvm.coro.begin(token %id, i8* %call)
+  %2 = bitcast i32* %n.addr to i8*
+  call void @ctor(i8* %2)
+  br label %for.cond
+
+for.cond:
+  %3 = load i32, i32* %n.addr
+  %dec = add nsw i32 %3, -1
+  store i32 %dec, i32* %n.addr
+  call void @print(i32 %3)
+  %4 = call i8 @llvm.coro.suspend(token none, i1 false)
+  %conv = sext i8 %4 to i32
+  switch i32 %conv, label %coro_Suspend [
+    i32 0, label %for.cond
+    i32 1, label %coro_Cleanup
+  ]
+
+coro_Cleanup:
+  %5 = call i8* @llvm.coro.free(token %id, i8* nonnull %1)
+  call void @free(i8* %5)
+  br label %coro_Suspend
+
+coro_Suspend:
+  call void @llvm.coro.end(i8* null, i1 false)
+  ret i8* %1
+}
+
+; CHECK-LABEL: @main
+define i32 @main() {
+entry:
+  %hdl = call i8* @f(i32 4)
+  call void @llvm.coro.resume(i8* %hdl)
+  call void @llvm.coro.resume(i8* %hdl)
+  call void @llvm.coro.destroy(i8* %hdl)
+  ret i32 0
+; CHECK:      call void @ctor
+; CHECK-NEXT: call void @print(i32 4)
+; CHECK-NEXT: call void @print(i32 3)
+; CHECK-NEXT: call void @print(i32 2)
+; CHECK:      ret i32 0
+}
+
+declare i8* @malloc(i32)
+declare void @free(i8*)
+declare void @print(i32)
+declare void @ctor(i8* nocapture readonly)
+
+declare token @llvm.coro.id(i32, i8*, i8*, i8*)
+declare i32 @llvm.coro.size.i32()
+declare i8* @llvm.coro.begin(token, i8*)
+declare i8 @llvm.coro.suspend(token, i1)
+declare i8* @llvm.coro.free(token, i8*)
+declare void @llvm.coro.end(i8*, i1)
+
+declare void @llvm.coro.resume(i8*)
+declare void @llvm.coro.destroy(i8*)