Fixes PR9730: indvars: An asserting value handle still pointed to this value

Modified LinearFunctionTestReplace to push the condition on the dead
list instead of eagerly deleting it. This can cause unnecessary
IV rewrites, which should have no effect on codegen and will not be an
issue once we stop generating canonical IVs.

llvm-svn: 130340

lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -275,7 +275,7 @@ ICmpInst *IndVarSimplify::LinearFunctionTestReplace(Loop *L,
   // update the branch to use the new comparison; in the common case this
   // will make old comparison dead.
   BI->setCondition(Cond);
-  RecursivelyDeleteTriviallyDeadInstructions(OrigCond);
+  DeadInsts.push_back(OrigCond);
 
   ++NumLFTR;
   Changed = true;

test/Transforms/IndVarSimplify/2009-04-27-Floating.ll

@@ -1,4 +1,4 @@
-; RUN: opt < %s -indvars -S | grep icmp | grep next
+; RUN: opt < %s -indvars -S | FileCheck %s
 ; PR4086
 declare void @foo()
 
@@ -6,13 +6,14 @@ define void @test() {
 entry:
         br label %loop_body
 
-loop_body:              
-        %i = phi float [ %nexti, %loop_body ], [ 0.0, %entry ]          
+loop_body:
+        %i = phi float [ %nexti, %loop_body ], [ 0.0, %entry ]
         tail call void @foo()
         %nexti = fadd float %i, 1.0
-        %less = fcmp olt float %nexti, 2.0              
+        ; CHECK: icmp ne i32 %{{[a-zA-Z$._0-9]+}}, 2
+        %less = fcmp olt float %nexti, 2.0
         br i1 %less, label %loop_body, label %done
 
-done:           
+done:
         ret void
 }