[llvm] 3d39612 - Coroutines: don't infer function attrs before lowering

[Tim Northover via llvm-commits]

Author: Tim Northover
Date: 2021-11-04T10:24:28Z
New Revision: 3d39612b3dd3f6b67ee63da305d30606abbe7287

URL: https://github.com/llvm/llvm-project/commit/3d39612b3dd3f6b67ee63da305d30606abbe7287
DIFF: https://github.com/llvm/llvm-project/commit/3d39612b3dd3f6b67ee63da305d30606abbe7287.diff

LOG: Coroutines: don't infer function attrs before lowering

Coroutines have weird semantics that don't quite match normal LLVM functions,
so trying to infer even simple attributes based on thier contents can go wrong.

Added: 
    

Modified: 
    llvm/lib/Transforms/IPO/FunctionAttrs.cpp
    llvm/test/Transforms/Coroutines/coro-retcon-alloca.ll
    llvm/test/Transforms/Coroutines/coro-retcon.ll
    llvm/test/Transforms/FunctionAttrs/noreturn.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index 8918d01f3ec27..935375e89393c 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -1752,7 +1752,8 @@ static SCCNodesResult createSCCNodeSet(ArrayRef<Function *> Functions) {
   SCCNodesResult Res;
   Res.HasUnknownCall = false;
   for (Function *F : Functions) {
-    if (!F || F->hasOptNone() || F->hasFnAttribute(Attribute::Naked)) {
+    if (!F || F->hasOptNone() || F->hasFnAttribute(Attribute::Naked) ||
+        F->isPresplitCoroutine()) {
       // Treat any function we're trying not to optimize as if it were an
       // indirect call and omit it from the node set used below.
       Res.HasUnknownCall = true;

diff  --git a/llvm/test/Transforms/Coroutines/coro-retcon-alloca.ll b/llvm/test/Transforms/Coroutines/coro-retcon-alloca.ll
index bf2862fcac2bd..be8df510ecfa2 100644
--- a/llvm/test/Transforms/Coroutines/coro-retcon-alloca.ll
+++ b/llvm/test/Transforms/Coroutines/coro-retcon-alloca.ll
@@ -10,7 +10,7 @@ define {i8*, i8*, i32} @f(i8* %buffer, i32 %n) {
 ; CHECK-NEXT:    [[N_VAL_SPILL_ADDR:%.*]] = getelementptr inbounds i8, i8* [[BUFFER:%.*]], i64 8
 ; CHECK-NEXT:    [[TMP0:%.*]] = bitcast i8* [[N_VAL_SPILL_ADDR]] to i32*
 ; CHECK-NEXT:    store i32 [[N:%.*]], i32* [[TMP0]], align 4
-; CHECK-NEXT:    [[TMP1:%.*]] = tail call i8* @allocate(i32 [[N]]) #[[ATTR0:[0-9]+]]
+; CHECK-NEXT:    [[TMP1:%.*]] = tail call i8* @allocate(i32 [[N]])
 ; CHECK-NEXT:    [[DOTSPILL_ADDR:%.*]] = bitcast i8* [[BUFFER]] to i8**
 ; CHECK-NEXT:    store i8* [[TMP1]], i8** [[DOTSPILL_ADDR]], align 8
 ; CHECK-NEXT:    [[TMP2:%.*]] = insertvalue { i8*, i8*, i32 } { i8* bitcast ({ i8*, i8*, i32 } (i8*, i1)* @f.resume.0 to i8*), i8* undef, i32 undef }, i8* [[TMP1]], 1

diff  --git a/llvm/test/Transforms/Coroutines/coro-retcon.ll b/llvm/test/Transforms/Coroutines/coro-retcon.ll
index 5c9e33897139b..7445ba8c1117d 100644
--- a/llvm/test/Transforms/Coroutines/coro-retcon.ll
+++ b/llvm/test/Transforms/Coroutines/coro-retcon.ll
@@ -72,7 +72,7 @@ entry:
 define hidden { i8*, i8* } @g(i8* %buffer, i16* %ptr) {
 ; CHECK-LABEL: @g(
 ; CHECK-NEXT:  coro.return:
-; CHECK-NEXT:    [[TMP0:%.*]] = tail call i8* @allocate(i32 8) #[[ATTR0:[0-9]+]]
+; CHECK-NEXT:    [[TMP0:%.*]] = tail call i8* @allocate(i32 8)
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast i8* [[BUFFER:%.*]] to i8**
 ; CHECK-NEXT:    store i8* [[TMP0]], i8** [[TMP1]], align 8
 ; CHECK-NEXT:    [[PTR_SPILL_ADDR:%.*]] = bitcast i8* [[TMP0]] to i16**

diff  --git a/llvm/test/Transforms/FunctionAttrs/noreturn.ll b/llvm/test/Transforms/FunctionAttrs/noreturn.ll
index 098788f93af8f..eba56c9630adb 100644
--- a/llvm/test/Transforms/FunctionAttrs/noreturn.ll
+++ b/llvm/test/Transforms/FunctionAttrs/noreturn.ll
@@ -71,3 +71,20 @@ define void @callsite_noreturn() {
   call i32 @f() noreturn
   ret void
 }
+
+; CHECK: Function Attrs: {{.*}}noreturn
+; CHECK-NEXT: @unreachable
+define void @unreachable() {
+  unreachable
+}
+
+; CHECK-NOT: Function Attrs: {{.*}}noreturn
+; CHECK: @coro
+define void @coro() "coroutine.presplit"="1" {
+  call token @llvm.coro.id.retcon.once(i32 0, i32 0, i8* null, i8* bitcast(void() *@coro to i8*), i8* null, i8* null)
+  call i1 @llvm.coro.end(i8* null, i1 false)
+  unreachable
+}
+
+declare token @llvm.coro.id.retcon.once(i32 %size, i32 %align, i8* %buffer, i8* %prototype, i8* %alloc, i8* %free)
+declare i1 @llvm.coro.end(i8*, i1)
\ No newline at end of file