From bc0b56732a2d1dc22767e0f3930f22a76d99470a Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Tue, 13 Jan 2009 20:24:13 +0000
Subject: [PATCH] The list-td and list-tdrr schedulers don't yet support
 physreg scheduling dependencies. Add assertion checks to help catch this.

It appears the Mips target defaults to list-td, and it has a
regression test that uses a physreg dependence. Such code was
liable to be miscompiled, and now evokes an assertion failure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62177 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp   | 6 +++++-
 lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp | 6 +++++-
 test/CodeGen/Generic/2006-07-03-schedulers.ll  | 5 +++--
 test/CodeGen/Mips/2008-07-23-fpcmp.ll          | 1 +
 4 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
index fea74ca3038..6f0767aa100 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
@@ -140,8 +140,12 @@ void ScheduleDAGList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
 
   // Top down: release successors.
   for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
-       I != E; ++I)
+       I != E; ++I) {
+    assert(!I->isAssignedRegDep() &&
+           "The list-td scheduler doesn't yet support physreg dependencies!");
+
     ReleaseSucc(SU, *I);
+  }
 
   SU->isScheduled = true;
   AvailableQueue->ScheduledNode(SU);
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index bc5443eaba8..03d3ef5feed 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -816,8 +816,12 @@ void ScheduleDAGRRList::ScheduleNodeTopDown(SUnit *SU, unsigned CurCycle) {
 
   // Top down: release successors
   for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
-       I != E; ++I)
+       I != E; ++I) {
+    assert(!I->isAssignedRegDep() &&
+           "The list-tdrr scheduler doesn't yet support physreg dependencies!");
+
     ReleaseSucc(SU, &*I);
+  }
 
   SU->isScheduled = true;
   AvailableQueue->ScheduledNode(SU);
diff --git a/test/CodeGen/Generic/2006-07-03-schedulers.ll b/test/CodeGen/Generic/2006-07-03-schedulers.ll
index 897fb78db22..4c4481ccad8 100644
--- a/test/CodeGen/Generic/2006-07-03-schedulers.ll
+++ b/test/CodeGen/Generic/2006-07-03-schedulers.ll
@@ -1,10 +1,11 @@
 ; RUN: llvm-as < %s | llc -pre-RA-sched=default
-; RUN: llvm-as < %s | llc -pre-RA-sched=list-td
-; RUN: llvm-as < %s | llc -pre-RA-sched=list-tdrr
 ; RUN: llvm-as < %s | llc -pre-RA-sched=list-burr
 ; RUN: llvm-as < %s | llc -pre-RA-sched=fast
 ; PR859
 
+; The top-down schedulers are excluded here because they don't yet support
+; targets that use physreg defs.
+
 declare i32 @printf(i8*, i32, float)
 
 define i32 @testissue(i32 %i, float %x, float %y) {
diff --git a/test/CodeGen/Mips/2008-07-23-fpcmp.ll b/test/CodeGen/Mips/2008-07-23-fpcmp.ll
index 7bc1f42d10a..ebb9c8a3bd6 100644
--- a/test/CodeGen/Mips/2008-07-23-fpcmp.ll
+++ b/test/CodeGen/Mips/2008-07-23-fpcmp.ll
@@ -1,6 +1,7 @@
 ; RUN: llvm-as < %s | llc -march=mips -f -o %t
 ; RUN: grep {c\\..*\\.s} %t | count 3
 ; RUN: grep {bc1\[tf\]} %t | count 3
+; XFAIL: *
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64"
 target triple = "mipsallegrexel-psp-elf"