Fix PR2346 by marking vaarg as volatile so that licm doesn't try to

hoist them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51356 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 34 insertions, 1 deletions

diff --git a/lib/Analysis/AliasSetTracker.cpp b/lib/Analysis/AliasSetTracker.cpp
index 68603e53b6..228bb80ae3 100644
--- a/lib/Analysis/AliasSetTracker.cpp
+++ b/lib/Analysis/AliasSetTracker.cpp
@@ -294,7 +294,10 @@ bool AliasSetTracker::add(FreeInst *FI) {
 
 bool AliasSetTracker::add(VAArgInst *VAAI) {
   bool NewPtr;
-  addPointer(VAAI->getOperand(0), ~0, AliasSet::ModRef, NewPtr);
+  AliasSet &AS = addPointer(VAAI->getOperand(0), ~0, AliasSet::ModRef, NewPtr);
+  
+  // Treat vaarg instructions as volatile (not to be moved).
+  AS.setVolatile();
   return NewPtr;
 }
 
diff --git a/test/Transforms/LICM/2008-05-20-AliasSetVAArg.ll b/test/Transforms/LICM/2008-05-20-AliasSetVAArg.ll
new file mode 100644
index 0000000000..dcb20e7bbd
--- /dev/null
+++ b/test/Transforms/LICM/2008-05-20-AliasSetVAArg.ll
@@ -0,0 +1,30 @@
+; RUN: llvm-as < %s | opt -licm -disable-output
+; PR2346
+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 triple = "i686-pc-linux-gnu"
+	%struct._zval_struct = type { %union._double, i32, i8, i8, i8, i8 }
+	%union._double = type { double }
+
+define i8* @zend_fetch_resource(%struct._zval_struct** %passed_id, i32 %default_id, i8* %resource_type_name, i32* %found_resource_type, i32 %num_resource_types, ...) {
+entry:
+	br label %whilebody.i.i
+
+whilebody.i.i:		; preds = %whilebody.i.i, %entry
+	br i1 false, label %ifthen.i.i, label %whilebody.i.i
+
+ifthen.i.i:		; preds = %whilebody.i.i
+	br label %forcond
+
+forcond:		; preds = %forbody, %ifthen.i.i
+	br i1 false, label %forbody, label %afterfor
+
+forbody:		; preds = %forcond
+	va_arg i8** null, i32		; <i32>:0 [#uses=0]
+	br i1 false, label %ifthen59, label %forcond
+
+ifthen59:		; preds = %forbody
+	unreachable
+
+afterfor:		; preds = %forcond
+	ret i8* null
+}