Fix PR2471, which is a bug involving an invalid promotion from a conditional load.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52525 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 72a27f5..54e611d 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -10062,10 +10062,16 @@
while (BBI != E) {
--BBI;
+ // If we see a free or a call (which might do a free) the pointer could be
+ // marked invalid.
+ if (isa<FreeInst>(BBI) || isa<CallInst>(BBI))
+ return false;
+
if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) {
if (LI->getOperand(0) == V) return true;
- } else if (StoreInst *SI = dyn_cast<StoreInst>(BBI))
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(BBI)) {
if (SI->getOperand(1) == V) return true;
+ }
}
return false;
diff --git a/test/Transforms/InstCombine/2008-06-19-UncondLoad.ll b/test/Transforms/InstCombine/2008-06-19-UncondLoad.ll
new file mode 100644
index 0000000..fa3dc0a
--- /dev/null
+++ b/test/Transforms/InstCombine/2008-06-19-UncondLoad.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep load | count 3
+; PR2471
+
+declare i32 @x(i32*)
+define i32 @b(i32* %a, i32* %b) {
+entry:
+ %tmp1 = load i32* %a
+ %tmp3 = load i32* %b
+ %add = add i32 %tmp1, %tmp3
+ %call = call i32 @x( i32* %a )
+ %tobool = icmp ne i32 %add, 0
+ ; not safe to turn into an uncond load
+ %cond = select i1 %tobool, i32* %b, i32* %a
+ %tmp8 = load i32* %cond
+ ret i32 %tmp8
+}