fix PR5827 by disabling the phi slicing transformation in a case

where instcombine would have to split a critical edge due to a
phi node of an invoke.  Since instcombine can't change the CFG,
it has to bail out from doing the transformation.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91763 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 77 insertions, 2 deletions

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index a6e0eef..4f4296f 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11234,6 +11234,23 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) {
   for (unsigned PHIId = 0; PHIId != PHIsToSlice.size(); ++PHIId) {
     PHINode *PN = PHIsToSlice[PHIId];
     
+    // Scan the input list of the PHI.  If any input is an invoke, and if the
+    // input is defined in the predecessor, then we won't be split the critical
+    // edge which is required to insert a truncate.  Because of this, we have to
+    // bail out.
+    for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
+      InvokeInst *II = dyn_cast<InvokeInst>(PN->getIncomingValue(i));
+      if (II == 0) continue;
+      if (II->getParent() != PN->getIncomingBlock(i))
+        continue;
+     
+      // If we have a phi, and if it's directly in the predecessor, then we have
+      // a critical edge where we need to put the truncate.  Since we can't
+      // split the edge in instcombine, we have to bail out.
+      return 0;
+    }
+      
+    
     for (Value::use_iterator UI = PN->use_begin(), E = PN->use_end();
          UI != E; ++UI) {
       Instruction *User = cast<Instruction>(*UI);
@@ -11316,7 +11333,9 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) {
           PredVal = EltPHI;
           EltPHI->addIncoming(PredVal, Pred);
           continue;
-        } else if (PHINode *InPHI = dyn_cast<PHINode>(PN)) {
+        }
+        
+        if (PHINode *InPHI = dyn_cast<PHINode>(PN)) {
           // If the incoming value was a PHI, and if it was one of the PHIs we
           // already rewrote it, just use the lowered value.
           if (Value *Res = ExtractedVals[LoweredPHIRecord(InPHI, Offset, Ty)]) {
diff --git a/test/Transforms/InstCombine/crash.ll b/test/Transforms/InstCombine/crash.ll
index 82ac575..732a882 100644
--- a/test/Transforms/InstCombine/crash.ll
+++ b/test/Transforms/InstCombine/crash.ll
@@ -1,5 +1,5 @@
 ; RUN: opt < %s -instcombine -S
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128:n8:16:32"
 target triple = "i386-apple-darwin10.0"
 
 define i32 @test0(i8 %tmp2) ssp {
@@ -148,3 +148,59 @@ entry:
   store i32* getelementptr (i32* bitcast (i32 (i32, i8**)* @test6 to i32*), i32 -2048), i32** @test6g, align 4
   unreachable
 }
+
+
+; PR5827
+
+%class.RuleBasedBreakIterator = type { i64 ()* }
+%class.UStack = type { i8** }
+
+define i32 @_ZN22RuleBasedBreakIterator15checkDictionaryEi(%class.RuleBasedBreakIterator* %this, i32 %x) align 2 {
+entry:
+  %breaks = alloca %class.UStack, align 4         ; <%class.UStack*> [#uses=3]
+  call void @_ZN6UStackC1Ei(%class.UStack* %breaks, i32 0)
+  %tobool = icmp ne i32 %x, 0                     ; <i1> [#uses=1]
+  br i1 %tobool, label %cond.end, label %cond.false
+
+terminate.handler:                                ; preds = %ehcleanup
+  %exc = call i8* @llvm.eh.exception()            ; <i8*> [#uses=1]
+  %0 = call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* %exc, i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*), i32 1) ; <i32> [#uses=0]
+  call void @_ZSt9terminatev() noreturn nounwind
+  unreachable
+
+ehcleanup:                                        ; preds = %cond.false
+  %exc1 = call i8* @llvm.eh.exception()           ; <i8*> [#uses=2]
+  %1 = call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* %exc1, i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*), i8* null) ; <i32> [#uses=0]
+  invoke void @_ZN6UStackD1Ev(%class.UStack* %breaks)
+          to label %cont unwind label %terminate.handler
+
+cont:                                             ; preds = %ehcleanup
+  call void @_Unwind_Resume_or_Rethrow(i8* %exc1)
+  unreachable
+
+cond.false:                                       ; preds = %entry
+  %tmp4 = getelementptr inbounds %class.RuleBasedBreakIterator* %this, i32 0, i32 0 ; <i64 ()**> [#uses=1]
+  %tmp5 = load i64 ()** %tmp4                     ; <i64 ()*> [#uses=1]
+  %call = invoke i64 %tmp5()
+          to label %cond.end unwind label %ehcleanup ; <i64> [#uses=1]
+
+cond.end:                                         ; preds = %cond.false, %entry
+  %cond = phi i64 [ 0, %entry ], [ %call, %cond.false ] ; <i64> [#uses=1]
+  %conv = trunc i64 %cond to i32                  ; <i32> [#uses=1]
+  call void @_ZN6UStackD1Ev(%class.UStack* %breaks)
+  ret i32 %conv
+}
+
+declare void @_ZN6UStackC1Ei(%class.UStack*, i32)
+
+declare void @_ZN6UStackD1Ev(%class.UStack*)
+
+declare i32 @__gxx_personality_v0(...)
+
+declare i8* @llvm.eh.exception() nounwind readonly
+
+declare i32 @llvm.eh.selector(i8*, i8*, ...) nounwind
+
+declare void @_ZSt9terminatev()
+
+declare void @_Unwind_Resume_or_Rethrow(i8*)