; RUN: opt < %s -gvn -enable-load-pre -S | FileCheck %s ; This testcase assumed we'll PRE the load into %for.cond, but we don't actually ; verify that doing so is safe. If there didn't _happen_ to be a load in ; %for.end, we would actually be lengthening the execution on some paths, and ; we were never actually checking that case. Now we actually do perform some ; conservative checking to make sure we don't make paths longer, but we don't ; currently get this case, which we got lucky on previously. ; ; Now that that faulty assumption is corrected, test that we DON'T incorrectly ; hoist the load. Doing the right thing for the wrong reasons is still a bug. @p = external global i32 define i32 @f(i32 %n) nounwind { entry: br label %for.cond for.cond: ; preds = %for.inc, %entry %i.0 = phi i32 [ 0, %entry ], [ %indvar.next, %for.inc ] ; <i32> [#uses=2] %cmp = icmp slt i32 %i.0, %n ; <i1> [#uses=1] br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge for.cond.for.end_crit_edge: ; preds = %for.cond br label %for.end ; CHECK: for.body: ; CHECK-NEXT: %tmp3 = load i32* @p for.body: ; preds = %for.cond %tmp3 = load i32* @p ; <i32> [#uses=1] %dec = add i32 %tmp3, -1 ; <i32> [#uses=2] store i32 %dec, i32* @p %cmp6 = icmp slt i32 %dec, 0 ; <i1> [#uses=1] br i1 %cmp6, label %for.body.for.end_crit_edge, label %for.inc ; CHECK: for.body.for.end_crit_edge: for.body.for.end_crit_edge: ; preds = %for.body br label %for.end for.inc: ; preds = %for.body %indvar.next = add i32 %i.0, 1 ; <i32> [#uses=1] br label %for.cond for.end: ; preds = %for.body.for.end_crit_edge, %for.cond.for.end_crit_edge %tmp9 = load i32* @p ; <i32> [#uses=1] ret i32 %tmp9 }