[llvm-commits] [llvm] r152595 - in /llvm/trunk: lib/Analysis/InstructionSimplify.cpp test/Transforms/EarlyCSE/instsimplify-dom.ll

[Eli Friedman]

Author: efriedma
Date: Mon Mar 12 20:06:07 2012
New Revision: 152595

URL: http://llvm.org/viewvc/llvm-project?rev=152595&view=rev
Log:
Fix regression from r151466: an we can't replace uses of an instruction reachable from the entry block with uses of an instruction not reachable from the entry block.  PR12231.


Added:
    llvm/trunk/test/Transforms/EarlyCSE/instsimplify-dom.ll
Modified:
    llvm/trunk/lib/Analysis/InstructionSimplify.cpp

Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=152595&r1=152594&r2=152595&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Mon Mar 12 20:06:07 2012
@@ -94,9 +94,13 @@
     return true;
 
   // If we have a DominatorTree then do a precise test.
-  if (DT)
-    return !DT->isReachableFromEntry(P->getParent()) ||
-      !DT->isReachableFromEntry(I->getParent()) || DT->dominates(I, P);
+  if (DT) {
+    if (!DT->isReachableFromEntry(P->getParent()))
+      return true;
+    if (!DT->isReachableFromEntry(I->getParent()))
+      return false;
+    return DT->dominates(I, P);
+  }
 
   // Otherwise, if the instruction is in the entry block, and is not an invoke,
   // then it obviously dominates all phi nodes.

Added: llvm/trunk/test/Transforms/EarlyCSE/instsimplify-dom.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/EarlyCSE/instsimplify-dom.ll?rev=152595&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/EarlyCSE/instsimplify-dom.ll (added)
+++ llvm/trunk/test/Transforms/EarlyCSE/instsimplify-dom.ll Mon Mar 12 20:06:07 2012
@@ -0,0 +1,19 @@
+; RUN: opt -early-cse -S < %s | FileCheck %s
+; PR12231
+
+declare i32 @f()
+
+define i32 @fn() {
+entry:
+  br label %lbl_1215
+
+lbl_1215:
+  %ins34 = phi i32 [ %ins35, %xxx ], [ undef, %entry ]
+  ret i32 %ins34
+
+xxx:
+  %ins35 = call i32 @f()
+  br label %lbl_1215
+}
+
+; CHECK: define i32 @fn