[PATCH] R600/SI: Fix crash in SIAnnotateControlFlow

[Tom Stellard]

When analyzing PHI loop conditions, we should handle undef values the same
as constants.
---
 lib/Target/R600/SIAnnotateControlFlow.cpp |  2 +-
 test/CodeGen/R600/si-annotate-cf-crash.ll | 62 +++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/R600/si-annotate-cf-crash.ll

diff --git a/lib/Target/R600/SIAnnotateControlFlow.cpp b/lib/Target/R600/SIAnnotateControlFlow.cpp
index 79f6532..a780171 100644
--- a/lib/Target/R600/SIAnnotateControlFlow.cpp
+++ b/lib/Target/R600/SIAnnotateControlFlow.cpp
@@ -217,7 +217,7 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken)
     for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
       Value *Incoming = Phi->getIncomingValue(i);
       BasicBlock *From = Phi->getIncomingBlock(i);
-      if (isa<ConstantInt>(Incoming)) {
+      if (isa<ConstantInt>(Incoming) || isa<UndefValue>(Incoming)) {
         NewPhi->addIncoming(Broken, From);
         continue;
       }
diff --git a/test/CodeGen/R600/si-annotate-cf-crash.ll b/test/CodeGen/R600/si-annotate-cf-crash.ll
new file mode 100644
index 0000000..a9f1835
--- /dev/null
+++ b/test/CodeGen/R600/si-annotate-cf-crash.ll
@@ -0,0 +1,62 @@
+; RUN: llc -march=amdgcn -mcpu=SI -verify-machineinstrs-asm < %s | FileCheck %s
+; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck %s
+
+; CHECK-LABEL: {{^}}test:
+; CHECK: s_endpgm
+define void @test(float addrspace(1)* nocapture %arg, i32 %arg1, float addrspace(1)* nocapture readonly %arg2, float %arg3) {
+bb:
+  br label %bb3
+
+bb3:                                              ; preds = %bb36, %bb
+  %tmp = phi i64 [ %tmp39, %bb36 ], [ 1, %bb ]
+  %tmp4 = phi float [ %tmp38, %bb36 ], [ 5.000000e+01, %bb ]
+  %tmp5 = phi i32 [ %tmp28, %bb36 ], [ 0, %bb ]
+  %tmp6 = phi i32 [ %tmp37, %bb36 ], [ 0, %bb ]
+  %tmp7 = trunc i64 %tmp to i32
+  %tmp8 = icmp eq i32 %tmp7, %arg1
+  br i1 %tmp8, label %bb26, label %bb9
+
+bb9:                                              ; preds = %bb18, %bb3
+  %tmp10 = phi i32 [ %tmp20, %bb18 ], [ %tmp7, %bb3 ]
+  %tmp11 = phi i64 [ %tmp19, %bb18 ], [ %tmp, %bb3 ]
+  %tmp12 = getelementptr inbounds float addrspace(1)* %arg2, i64 %tmp11
+  %tmp13 = load float addrspace(1)* %tmp12, align 4
+  %tmp17 = fcmp une float %tmp13, %arg3
+  br i1 %tmp17, label %bb22, label %bb18
+
+bb18:                                             ; preds = %bb9
+  %tmp19 = add nuw nsw i64 %tmp11, 1
+  %tmp20 = trunc i64 %tmp19 to i32
+  %tmp21 = icmp eq i32 %tmp20, %arg1
+  br i1 %tmp21, label %bb22, label %bb9
+
+bb22:                                             ; preds = %bb18, %bb9
+  %tmp23 = phi i1 [ false, %bb9 ], [ true, %bb18 ]
+  %tmp24 = phi i32 [ %tmp10, %bb9 ], [ %arg1, %bb18 ]
+  %tmp25 = phi i64 [ %tmp11, %bb9 ], [ %tmp19, %bb18 ]
+  br label %bb26
+
+bb26:                                             ; preds = %bb22, %bb3
+  %tmp27 = phi i1 [ true, %bb3 ], [ %tmp23, %bb22 ]
+  %tmp28 = phi i32 [ %arg1, %bb3 ], [ %tmp24, %bb22 ]
+  %tmp29 = phi i64 [ %tmp, %bb3 ], [ %tmp25, %bb22 ]
+  %tmp30 = sub nsw i32 %tmp28, %tmp5
+  %tmp31 = icmp slt i32 %tmp6, %tmp30
+  br i1 %tmp31, label %bb32, label %bb36
+
+bb32:                                             ; preds = %bb26
+  %tmp33 = add nsw i64 %tmp29, -1
+  %tmp34 = getelementptr inbounds float addrspace(1)* %arg2, i64 %tmp33
+  %tmp35 = load float addrspace(1)* %tmp34, align 4
+  br label %bb36
+
+bb36:                                             ; preds = %bb32, %bb26
+  %tmp37 = phi i32 [ %tmp30, %bb32 ], [ %tmp6, %bb26 ]
+  %tmp38 = phi float [ %tmp35, %bb32 ], [ %tmp4, %bb26 ]
+  %tmp39 = add nuw nsw i64 %tmp29, 1
+  br i1 %tmp27, label %bb40, label %bb3
+
+bb40:                                             ; preds = %bb36
+  store float %tmp38, float addrspace(1)* %arg, align 4
+  ret void
+}
-- 
2.0.4