if (!PN->hasOneUse()) {
// Walk the use list for the instruction, comparing them to I.
for (Value::use_iterator UI = PN->use_begin(), E = PN->use_end();
- UI != E; ++UI)
- if (!I.isIdenticalTo(cast<Instruction>(*UI)))
+ UI != E; ++UI) {
+ Instruction *User = cast<Instruction>(*UI);
+ if (User != &I && !I.isIdenticalTo(User))
return 0;
+ }
// Otherwise, we can replace *all* users with the new PHI we form.
}
if (InvokeInst *II = dyn_cast<InvokeInst>(InVal))
if (II->getParent() == NonConstBB)
return 0;
+
+ // If the incoming non-constant value is in I's block, we will remove one
+ // instruction, but insert another equivalent one, leading to infinite
+ // instcombine.
+ if (NonConstBB == I.getParent())
+ return 0;
}
// If there is exactly one non-constant value, we can insert a copy of the
ret %struct.basic_ios* %0
}
+; PR9013
+define void @test18() nounwind ssp {
+entry:
+ br label %for.cond
+
+for.cond: ; preds = %for.inc, %entry
+ %l_197.0 = phi i32 [ 0, %entry ], [ %sub.i, %for.inc ]
+ br label %for.inc
+
+for.inc: ; preds = %for.cond
+ %conv = and i32 %l_197.0, 255
+ %sub.i = add nsw i32 %conv, -1
+ br label %for.cond
+
+return: ; No predecessors!
+ ret void
+}