Currently EH lowering code expects typeinfo to be global only.

This assumption is not satisfied due to global mergeing.
Workaround the issue by temporary disablinge mergeing of const globals.
Also, ignore LLVM "special" globals. This fixes PR7716

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109423 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 106 insertions, 2 deletions

diff --git a/lib/Target/ARM/ARMGlobalMerge.cpp b/lib/Target/ARM/ARMGlobalMerge.cpp
index cb7947b2..af7298a 100644
--- a/lib/Target/ARM/ARMGlobalMerge.cpp
+++ b/lib/Target/ARM/ARMGlobalMerge.cpp
@@ -178,6 +178,11 @@ bool ARMGlobalMerge::doInitialization(Module& M) {
     if (I->getAlignment() != 0)
       continue;
 
+    // Ignore all 'special' globals.
+    if (I->getName().startswith("llvm.") ||
+        I->getName().startswith(".llvm."))
+      continue;
+
     if (TD->getTypeAllocSize(I->getType()) < MaxOffset) {
       if (I->isConstant())
         ConstGlobals.push_back(I);
@@ -188,8 +193,12 @@ bool ARMGlobalMerge::doInitialization(Module& M) {
 
   if (Globals.size() > 1)
     Changed |= doMerge(Globals, M, false);
-  if (ConstGlobals.size() > 1)
-    Changed |= doMerge(ConstGlobals, M, true);
+  // FIXME: This currently breaks the EH processing due to way how the 
+  // typeinfo detection works. We might want to detect the TIs and ignore 
+  // them in the future.
+  
+  // if (ConstGlobals.size() > 1)
+  //  Changed |= doMerge(ConstGlobals, M, true);
 
   return Changed;
 }
diff --git a/test/CodeGen/ARM/2010-07-26-GlobalMerge.ll b/test/CodeGen/ARM/2010-07-26-GlobalMerge.ll
new file mode 100644
index 0000000..c03c815
--- /dev/null
+++ b/test/CodeGen/ARM/2010-07-26-GlobalMerge.ll
@@ -0,0 +1,95 @@
+; RUN: llc -enable-correct-eh-support < %s
+; PR7716
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:64:64-v128:128:128-a0:0:32-n32"
+target triple = "thumbv7-apple-darwin10.0.0"
+
+%0 = type { i8*, i8* }
+%struct.A = type { i32 }
+
+@d = internal global i32 0, align 4               ; <i32*> [#uses=6]
+@_ZTVN10__cxxabiv117__class_type_infoE = external global i8* ; <i8**> [#uses=1]
+@_ZTS1A = internal constant [3 x i8] c"1A\00"     ; <[3 x i8]*> [#uses=1]
+@_ZTI1A = internal constant %0 { i8* bitcast (i8** getelementptr inbounds (i8** @_ZTVN10__cxxabiv117__class_type_infoE, i32 2) to i8*), i8* getelementptr inbounds ([3 x i8]* @_ZTS1A, i32 0, i32 0) } ; <%0*> [#uses=1]
+@.str2 = private constant [18 x i8] c"c == %d, d == %d\0A\00" ; <[18 x i8]*> [#uses=1]
+@.str3 = private constant [16 x i8] c"A(const A&) %d\0A\00" ; <[16 x i8]*> [#uses=1]
+@.str4 = private constant [9 x i8] c"~A() %d\0A\00" ; <[9 x i8]*> [#uses=1]
+@.str5 = private constant [8 x i8] c"A() %d\0A\00" ; <[8 x i8]*> [#uses=1]
+@str = internal constant [14 x i8] c"Throwing 1...\00" ; <[14 x i8]*> [#uses=1]
+@str1 = internal constant [8 x i8] c"Caught.\00"  ; <[8 x i8]*> [#uses=1]
+
+declare i32 @printf(i8* nocapture, ...) nounwind
+
+declare i8* @__cxa_allocate_exception(i32)
+
+declare i8* @llvm.eh.exception() nounwind readonly
+
+declare i32 @__gxx_personality_sj0(...)
+
+declare i32 @llvm.eh.selector(i8*, i8*, ...) nounwind
+
+declare i32 @llvm.eh.typeid.for(i8*) nounwind
+
+declare void @_Unwind_SjLj_Resume(i8*)
+
+define internal void @_ZN1AD1Ev(%struct.A* nocapture %this) nounwind ssp align 2 {
+entry:
+  %tmp.i = getelementptr inbounds %struct.A* %this, i32 0, i32 0 ; <i32*> [#uses=1]
+  %tmp2.i = load i32* %tmp.i                      ; <i32> [#uses=1]
+  %call.i = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([9 x i8]* @.str4, i32 0, i32 0), i32 %tmp2.i) nounwind ; <i32> [#uses=0]
+  %tmp3.i = load i32* @d                          ; <i32> [#uses=1]
+  %inc.i = add nsw i32 %tmp3.i, 1                 ; <i32> [#uses=1]
+  store i32 %inc.i, i32* @d
+  ret void
+}
+
+declare void @__cxa_throw(i8*, i8*, i8*)
+
+define i32 @main() ssp {
+entry:
+  %puts.i = tail call i32 @puts(i8* getelementptr inbounds ([14 x i8]* @str, i32 0, i32 0)) ; <i32> [#uses=0]
+  %exception.i = tail call i8* @__cxa_allocate_exception(i32 4) nounwind ; <i8*> [#uses=2]
+  %tmp2.i.i.i = bitcast i8* %exception.i to i32*  ; <i32*> [#uses=1]
+  store i32 1, i32* %tmp2.i.i.i
+  %call.i.i.i = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([8 x i8]* @.str5, i32 0, i32 0), i32 1) nounwind ; <i32> [#uses=0]
+  invoke void @__cxa_throw(i8* %exception.i, i8* bitcast (%0* @_ZTI1A to i8*), i8* bitcast (void (%struct.A*)* @_ZN1AD1Ev to i8*)) noreturn
+          to label %.noexc unwind label %lpad
+
+.noexc:                                           ; preds = %entry
+  unreachable
+
+try.cont:                                         ; preds = %lpad
+  %0 = tail call i8* @__cxa_get_exception_ptr(i8* %exn) nounwind ; <i8*> [#uses=0]
+  %call.i.i = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([16 x i8]* @.str3, i32 0, i32 0), i32 2) nounwind ; <i32> [#uses=0]
+  %1 = tail call i8* @__cxa_begin_catch(i8* %exn) nounwind ; <i8*> [#uses=0]
+  %puts = tail call i32 @puts(i8* getelementptr inbounds ([8 x i8]* @str1, i32 0, i32 0)) ; <i32> [#uses=0]
+  %call.i.i3 = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([9 x i8]* @.str4, i32 0, i32 0), i32 2) nounwind ; <i32> [#uses=0]
+  %tmp3.i.i = load i32* @d                        ; <i32> [#uses=1]
+  %inc.i.i4 = add nsw i32 %tmp3.i.i, 1            ; <i32> [#uses=1]
+  store i32 %inc.i.i4, i32* @d
+  tail call void @__cxa_end_catch()
+  %tmp13 = load i32* @d                           ; <i32> [#uses=1]
+  %call14 = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([18 x i8]* @.str2, i32 0, i32 0), i32 2, i32 %tmp13) ; <i32> [#uses=0]
+  %tmp16 = load i32* @d                           ; <i32> [#uses=1]
+  %cmp = icmp ne i32 %tmp16, 2                    ; <i1> [#uses=1]
+  %conv = zext i1 %cmp to i32                     ; <i32> [#uses=1]
+  ret i32 %conv
+
+lpad:                                             ; preds = %entry
+  %exn = tail call i8* @llvm.eh.exception() nounwind ; <i8*> [#uses=4]
+  %eh.selector = tail call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* %exn, i8* bitcast (i32 (...)* @__gxx_personality_sj0 to i8*), i8* bitcast (%0* @_ZTI1A to i8*), i8* null) nounwind ; <i32> [#uses=1]
+  %2 = tail call i32 @llvm.eh.typeid.for(i8* bitcast (%0* @_ZTI1A to i8*)) nounwind ; <i32> [#uses=1]
+  %3 = icmp eq i32 %eh.selector, %2               ; <i1> [#uses=1]
+  br i1 %3, label %try.cont, label %eh.resume
+
+eh.resume:                                        ; preds = %lpad
+  tail call void @_Unwind_SjLj_Resume(i8* %exn) noreturn
+  unreachable
+}
+
+declare i8* @__cxa_get_exception_ptr(i8*)
+
+declare i8* @__cxa_begin_catch(i8*)
+
+declare void @__cxa_end_catch()
+
+declare i32 @puts(i8* nocapture) nounwind