From: Cameron Zwarich <zwarich@apple.com>
Date: Fri, 27 May 2011 05:04:51 +0000 (+0000)
Subject: Fix PR10029 - VerifyCoalescing failure on patterns_dfa.c of 445.gobmk.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=f031d0977f8b03288ed32ff14f71c79e81914f39;p=oota-llvm.git

Fix PR10029 - VerifyCoalescing failure on patterns_dfa.c of 445.gobmk.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132181 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp
index 48d8ab1658d..52693f03e82 100644
--- a/lib/CodeGen/UnreachableBlockElim.cpp
+++ b/lib/CodeGen/UnreachableBlockElim.cpp
@@ -196,8 +196,11 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
         temp->eraseFromParent();
         ModifiedPHI = true;
 
-        if (Input != Output)
-          F.getRegInfo().replaceRegWith(Output, Input);
+        if (Input != Output) {
+          MachineRegisterInfo &MRI = F.getRegInfo();
+          MRI.constrainRegClass(Input, MRI.getRegClass(Output));
+          MRI.replaceRegWith(Output, Input);
+        }
 
         continue;
       }
diff --git a/test/CodeGen/X86/2011-05-26-UnreachableBlockElim.ll b/test/CodeGen/X86/2011-05-26-UnreachableBlockElim.ll
new file mode 100644
index 00000000000..0f18f0969ba
--- /dev/null
+++ b/test/CodeGen/X86/2011-05-26-UnreachableBlockElim.ll
@@ -0,0 +1,53 @@
+; RUN: llc < %s -verify-coalescing
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-macosx10.6.0"
+
+%struct.attrib = type { i32, i32 }
+%struct.dfa = type { [80 x i8], i32, %struct.state*, i32, i32, %struct.attrib*, i32, i32 }
+%struct.state = type { i32, [4 x i32] }
+
+@aux_temp = external global %struct.dfa, align 8
+
+declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readnone
+
+declare void @__memset_chk() nounwind
+
+define void @dfa_add_string() nounwind uwtable ssp {
+entry:
+  br label %if.end.i
+
+if.end.i:                                         ; preds = %entry
+  %idxprom.i = add i64 0, 1
+  br i1 undef, label %land.end.thread.i, label %land.end.i
+
+land.end.thread.i:                                ; preds = %if.end.i
+  %0 = call i64 @llvm.objectsize.i64(i8* undef, i1 false) nounwind
+  %cmp1710.i = icmp eq i64 %0, -1
+  br i1 %cmp1710.i, label %cond.false156.i, label %cond.true138.i
+
+land.end.i:                                       ; preds = %if.end.i
+  %1 = call i64 @llvm.objectsize.i64(i8* undef, i1 false) nounwind
+  %cmp17.i = icmp eq i64 %1, -1
+  br i1 %cmp17.i, label %cond.false156.i, label %cond.true138.i
+
+cond.true138.i:                                   ; preds = %for.end.i, %land.end.thread.i
+  call void @__memset_chk() nounwind
+  br label %cond.end166.i
+
+cond.false156.i:                                  ; preds = %for.end.i, %land.end.thread.i
+  %idxprom1114.i = phi i64 [ undef, %land.end.thread.i ], [ %idxprom.i, %land.end.i ]
+  call void @__memset_chk() nounwind
+  br label %cond.end166.i
+
+cond.end166.i:                                    ; preds = %cond.false156.i, %cond.true138.i
+  %idxprom1113.i = phi i64 [ %idxprom1114.i, %cond.false156.i ], [ undef, %cond.true138.i ]
+  %tmp235.i = load %struct.state** getelementptr inbounds (%struct.dfa* @aux_temp, i64 0, i32 2), align 8, !tbaa !0
+  %att.i = getelementptr inbounds %struct.state* %tmp235.i, i64 %idxprom1113.i, i32 0
+  store i32 0, i32* %att.i, align 4, !tbaa !3
+  ret void
+}
+
+!0 = metadata !{metadata !"any pointer", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}
+!3 = metadata !{metadata !"int", metadata !1}