[llvm] r299771 - [coroutines] Insert spills of PHI instructions correctly
Gor Nishanov via llvm-commits
llvm-commits at lists.llvm.org
Fri Apr 7 07:16:49 PDT 2017
Author: gornishanov
Date: Fri Apr 7 09:16:49 2017
New Revision: 299771
URL: http://llvm.org/viewvc/llvm-project?rev=299771&view=rev
Log:
[coroutines] Insert spills of PHI instructions correctly
Summary:
Fix a bug where we were inserting a spill in between the PHIs in the beginning of the block.
Consider this fragment:
```
begin:
%phi1 = phi i32 [ 0, %entry ], [ 2, %alt ]
%phi2 = phi i32 [ 1, %entry ], [ 3, %alt ]
%sp1 = call i8 @llvm.coro.suspend(token none, i1 false)
switch i8 %sp1, label %suspend [i8 0, label %resume
i8 1, label %cleanup]
resume:
call i32 @print(i32 %phi1)
```
Unless we are spilling the argument or result of the invoke, we were always inserting the spill immediately following the instruction.
The fix adds a check that if the spilled instruction is a PHI Node, select an appropriate insert point with `getFirstInsertionPt()` that
skips all the PHI Nodes and EH pads.
Reviewers: majnemer, rnk
Reviewed By: rnk
Subscribers: qcolombet, EricWF, llvm-commits
Differential Revision: https://reviews.llvm.org/D31799
Added:
llvm/trunk/test/Transforms/Coroutines/coro-spill-after-phi.ll
Modified:
llvm/trunk/lib/Transforms/Coroutines/CoroFrame.cpp
Modified: llvm/trunk/lib/Transforms/Coroutines/CoroFrame.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Coroutines/CoroFrame.cpp?rev=299771&r1=299770&r2=299771&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Coroutines/CoroFrame.cpp (original)
+++ llvm/trunk/lib/Transforms/Coroutines/CoroFrame.cpp Fri Apr 7 09:16:49 2017
@@ -435,6 +435,10 @@ static Instruction *insertSpills(SpillIn
// normal edge and insert the spill in the new block.
auto NewBB = SplitEdge(II->getParent(), II->getNormalDest());
InsertPt = NewBB->getTerminator();
+ } else if (dyn_cast<PHINode>(CurrentValue)) {
+ // Skip the PHINodes and EH pads instructions.
+ InsertPt =
+ &*cast<Instruction>(E.def())->getParent()->getFirstInsertionPt();
} else {
// For all other values, the spill is placed immediately after
// the definition.
Added: llvm/trunk/test/Transforms/Coroutines/coro-spill-after-phi.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Coroutines/coro-spill-after-phi.ll?rev=299771&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Coroutines/coro-spill-after-phi.ll (added)
+++ llvm/trunk/test/Transforms/Coroutines/coro-spill-after-phi.ll Fri Apr 7 09:16:49 2017
@@ -0,0 +1,60 @@
+; Verifies that we insert spills of PHI instruction _after) all PHI Nodes
+; RUN: opt < %s -coro-split -S | FileCheck %s
+
+define i8* @f(i1 %n) "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)
+ br i1 %n, label %begin, label %alt
+alt:
+ br label %begin
+
+begin:
+ %phi1 = phi i32 [ 0, %entry ], [ 2, %alt ]
+ %phi2 = phi i32 [ 1, %entry ], [ 3, %alt ]
+
+ %sp1 = call i8 @llvm.coro.suspend(token none, i1 false)
+ switch i8 %sp1, label %suspend [i8 0, label %resume
+ i8 1, label %cleanup]
+resume:
+ call i32 @print(i32 %phi1)
+ call i32 @print(i32 %phi2)
+ 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
+}
+
+; Verifies that the both phis are stored correctly in the coroutine frame
+; CHECK: %f.Frame = type { void (%f.Frame*)*, void (%f.Frame*)*, i1, i1, i32, i32 }
+; CHECK-LABEL: @f(
+; CHECK: store void (%f.Frame*)* @f.destroy, void (%f.Frame*)** %destroy.addr
+; CHECK: %phi1 = select i1 %n, i32 0, i32 2
+; CHECK: %phi2 = select i1 %n, i32 1, i32 3
+; CHECK: %phi2.spill.addr = getelementptr inbounds %f.Frame, %f.Frame* %FramePtr, i32 0, i32 5
+; CHECK: store i32 %phi2, i32* %phi2.spill.addr
+; CHECK: %phi1.spill.addr = getelementptr inbounds %f.Frame, %f.Frame* %FramePtr, i32 0, i32 4
+; CHECK: store i32 %phi1, i32* %phi1.spill.addr
+; CHECK: ret i8* %hdl
+
+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 noalias i8* @malloc(i32)
+declare i32 @print(i32)
+declare void @free(i8*)
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