[llvm] 21aa4d5 - [NFC] [Coroutines] Add a test for icmp use of coro.suspend to prevent musttail call converting

[Chuanqi Xu via llvm-commits]

Author: Chuanqi Xu
Date: 2021-12-27T17:28:13+08:00
New Revision: 21aa4d5d5ef947d824c50a22d15fb93d7df0b711

URL: https://github.com/llvm/llvm-project/commit/21aa4d5d5ef947d824c50a22d15fb93d7df0b711
DIFF: https://github.com/llvm/llvm-project/commit/21aa4d5d5ef947d824c50a22d15fb93d7df0b711.diff

LOG: [NFC] [Coroutines] Add a test for icmp use of coro.suspend to prevent musttail call converting

Add a test to show the false negative optimization oppotunity to not convert a resume
call to musttail call. It should could be.

Added: 
    llvm/test/Transforms/Coroutines/coro-split-musttail4.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/Coroutines/coro-split-musttail4.ll b/llvm/test/Transforms/Coroutines/coro-split-musttail4.ll
new file mode 100644
index 0000000000000..4cba73c5e6ff6
--- /dev/null
+++ b/llvm/test/Transforms/Coroutines/coro-split-musttail4.ll
@@ -0,0 +1,58 @@
+; Tests that coro-split will convert a call before coro.suspend to a musttail call
+; while the user of the coro.suspend is a icmpinst.
+; RUN: opt < %s -passes='cgscc(coro-split),simplifycfg,early-cse' -S | FileCheck %s
+
+define void @fakeresume1(i8*)  {
+entry:
+  ret void;
+}
+
+define void @f() #0 {
+entry:
+  %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
+  %alloc = call i8* @malloc(i64 16) #3
+  %vFrame = call noalias nonnull i8* @llvm.coro.begin(token %id, i8* %alloc)
+
+  %save = call token @llvm.coro.save(i8* null)
+  call fastcc void @fakeresume1(i8* null)
+
+  %suspend = call i8 @llvm.coro.suspend(token %save, i1 false)
+  %switch = icmp ult i8 %suspend, 2
+  br i1 %switch, label %cleanup, label %coro.end
+
+cleanup:
+  %free.handle = call i8* @llvm.coro.free(token %id, i8* %vFrame)
+  %.not = icmp eq i8* %free.handle, null
+  br i1 %.not, label %coro.end, label %coro.free
+
+coro.free:
+  call void @delete(i8* nonnull %free.handle) #2
+  br label %coro.end
+
+coro.end:
+  call i1 @llvm.coro.end(i8* null, i1 false)
+  ret void
+}
+
+; FIXME: The fakerresume here should be musttail call.
+; CHECK-LABEL: @f.resume(
+; CHECK-NOT: musttail call fastcc void @fakeresume1(
+
+
+declare token @llvm.coro.id(i32, i8* readnone, i8* nocapture readonly, i8*) #1
+declare i1 @llvm.coro.alloc(token) #2
+declare i64 @llvm.coro.size.i64() #3
+declare i8* @llvm.coro.begin(token, i8* writeonly) #2
+declare token @llvm.coro.save(i8*) #2
+declare i8* @llvm.coro.frame() #3
+declare i8 @llvm.coro.suspend(token, i1) #2
+declare i8* @llvm.coro.free(token, i8* nocapture readonly) #1
+declare i1 @llvm.coro.end(i8*, i1) #2
+declare i8* @llvm.coro.subfn.addr(i8* nocapture readonly, i8) #1
+declare i8* @malloc(i64)
+declare void @delete(i8* nonnull) #2
+
+attributes #0 = { "coroutine.presplit"="1" }
+attributes #1 = { argmemonly nounwind readonly }
+attributes #2 = { nounwind }
+attributes #3 = { nounwind readnone }
\ No newline at end of file