[llvm-commits] [llvm] r51216 - in /llvm/trunk: lib/VMCore/ConstantFold.cpp test/Transforms/InstCombine/2008-05-17-FoldIntToPtr.ll

[Nick Lewycky]

Author: nicholas
Date: Sat May 17 04:03:26 2008
New Revision: 51216

URL: http://llvm.org/viewvc/llvm-project?rev=51216&view=rev
Log:
Constant fold inttoptr and ptrtoint.

Added:
    llvm/trunk/test/Transforms/InstCombine/2008-05-17-FoldIntToPtr.ll
Modified:
    llvm/trunk/lib/VMCore/ConstantFold.cpp

Modified: llvm/trunk/lib/VMCore/ConstantFold.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/ConstantFold.cpp?rev=51216&r1=51215&r2=51216&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/ConstantFold.cpp (original)
+++ llvm/trunk/lib/VMCore/ConstantFold.cpp Sat May 17 04:03:26 2008
@@ -1029,6 +1029,29 @@
         }
       break;
 
+    case Instruction::PtrToInt:
+    case Instruction::IntToPtr:
+      // inttoptr(x1) != inttoptr(x2) iff x1 != x2
+      if (const ConstantExpr *CE2 = dyn_cast<ConstantExpr>(V2))
+        if (CE1->getOpcode() == CE2->getOpcode()) {
+          Constant *Op1 = const_cast<Constant*>(CE1Op0);
+          Constant *Op2 = CE2->getOperand(0);
+          if (CE1Op->getType() == CE2Op->getType()) {
+            ConstantInt *R = 0;
+
+            ICmpInst::Predicate pred = ICmpInst::ICMP_EQ;
+            R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, Op1, Op2));
+            if (R && !R->isZero()) 
+              return pred;
+
+            pred = ICmpInst::ICMP_NE;
+            R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, Op1, Op2));
+            if (R && !R->isZero()) 
+              return pred;
+          }
+        }
+      break;
+
     case Instruction::GetElementPtr:
       // Ok, since this is a getelementptr, we know that the constant has a
       // pointer type.  Check the various cases.

Added: llvm/trunk/test/Transforms/InstCombine/2008-05-17-FoldIntToPtr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2008-05-17-FoldIntToPtr.ll?rev=51216&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2008-05-17-FoldIntToPtr.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2008-05-17-FoldIntToPtr.ll Sat May 17 04:03:26 2008
@@ -0,0 +1,8 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {ret i1 false}
+; PR2329
+
+define i1 @f() {
+  %x = icmp eq i8* inttoptr (i32 1 to i8*), inttoptr (i32 2 to i8*)
+  ret i1 %x
+}
+