From 38c18efe4137fb97464c7bc3428a5da19874a578 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Thu, 6 Mar 2014 17:33:55 +0000
Subject: [PATCH] Teach lint about address spaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203132 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/IR/InstrTypes.h         |  5 +++++
 lib/Analysis/Lint.cpp                | 11 +++++------
 lib/IR/Instructions.cpp              | 23 +++++++++++++++++++++--
 test/Analysis/Lint/address-spaces.ll | 25 +++++++++++++++++++++++++
 4 files changed, 56 insertions(+), 8 deletions(-)
 create mode 100644 test/Analysis/Lint/address-spaces.ll

diff --git a/include/llvm/IR/InstrTypes.h b/include/llvm/IR/InstrTypes.h
index 4e247e9c9c9..35357b14588 100644
--- a/include/llvm/IR/InstrTypes.h
+++ b/include/llvm/IR/InstrTypes.h
@@ -582,6 +582,11 @@ public:
     Type *IntPtrTy ///< Integer type corresponding to pointer
   ) const;
 
+  /// @brief Determine if this cast is a no-op cast.
+  bool isNoopCast(
+    const DataLayout *DL ///< DataLayout to get the Int Ptr type from.
+  ) const;
+
   /// Determine how a pair of casts can be eliminated, if they can be at all.
   /// This is a helper function for both CastInst and ConstantExpr.
   /// @returns 0 if the CastInst pair can't be eliminated, otherwise
diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp
index 5c44638fbb0..b2182b146d7 100644
--- a/lib/Analysis/Lint.cpp
+++ b/lib/Analysis/Lint.cpp
@@ -16,7 +16,7 @@
 // those aren't comprehensive either. Second, many conditions cannot be
 // checked statically. This pass does no dynamic instrumentation, so it
 // can't check for all possible problems.
-// 
+//
 // Another limitation is that it assumes all code will be executed. A store
 // through a null pointer in a basic block which is never reached is harmless,
 // but this pass will warn about it anyway. This is the main reason why most
@@ -26,12 +26,12 @@
 // less obvious. If an optimization pass appears to be introducing a warning,
 // it may be that the optimization pass is merely exposing an existing
 // condition in the code.
-// 
+//
 // This code may be run before instcombine. In many cases, instcombine checks
 // for the same kinds of things and turns instructions with undefined behavior
 // into unreachable (or equivalent). Because of this, this pass makes some
 // effort to look through bitcasts and so on.
-// 
+//
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/Lint.h"
@@ -652,8 +652,7 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk,
       if (W != V)
         return findValueImpl(W, OffsetOk, Visited);
   } else if (CastInst *CI = dyn_cast<CastInst>(V)) {
-    if (CI->isNoopCast(DL ? DL->getIntPtrType(V->getContext()) :
-                            Type::getInt64Ty(V->getContext())))
+    if (CI->isNoopCast(DL))
       return findValueImpl(CI->getOperand(0), OffsetOk, Visited);
   } else if (ExtractValueInst *Ex = dyn_cast<ExtractValueInst>(V)) {
     if (Value *W = FindInsertedValue(Ex->getAggregateOperand(),
@@ -666,7 +665,7 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk,
       if (CastInst::isNoopCast(Instruction::CastOps(CE->getOpcode()),
                                CE->getOperand(0)->getType(),
                                CE->getType(),
-                               DL ? DL->getIntPtrType(V->getContext()) :
+                               DL ? DL->getIntPtrType(V->getType()) :
                                     Type::getInt64Ty(V->getContext())))
         return findValueImpl(CE->getOperand(0), OffsetOk, Visited);
     } else if (CE->getOpcode() == Instruction::ExtractValue) {
diff --git a/lib/IR/Instructions.cpp b/lib/IR/Instructions.cpp
index c89365fcda6..c3a34a2ccd7 100644
--- a/lib/IR/Instructions.cpp
+++ b/lib/IR/Instructions.cpp
@@ -2115,8 +2115,27 @@ bool CastInst::isNoopCast(Type *IntPtrTy) const {
   return isNoopCast(getOpcode(), getOperand(0)->getType(), getType(), IntPtrTy);
 }
 
-/// This function determines if a pair of casts can be eliminated and what 
-/// opcode should be used in the elimination. This assumes that there are two 
+bool CastInst::isNoopCast(const DataLayout *DL) const {
+  if (!DL) {
+    // Assume maximum pointer size.
+    return isNoopCast(Type::getInt64Ty(getContext()));
+  }
+
+  Type *PtrOpTy = 0;
+  if (getOpcode() == Instruction::PtrToInt)
+    PtrOpTy = getOperand(0)->getType();
+  else if (getOpcode() == Instruction::IntToPtr)
+    PtrOpTy = getType();
+
+  Type *IntPtrTy = PtrOpTy
+                 ? DL->getIntPtrType(PtrOpTy)
+                 : DL->getIntPtrType(getContext(), 0);
+
+  return isNoopCast(getOpcode(), getOperand(0)->getType(), getType(), IntPtrTy);
+}
+
+/// This function determines if a pair of casts can be eliminated and what
+/// opcode should be used in the elimination. This assumes that there are two
 /// instructions like this:
 /// *  %F = firstOpcode SrcTy %x to MidTy
 /// *  %S = secondOpcode MidTy %F to DstTy
diff --git a/test/Analysis/Lint/address-spaces.ll b/test/Analysis/Lint/address-spaces.ll
new file mode 100644
index 00000000000..46ee1d734ba
--- /dev/null
+++ b/test/Analysis/Lint/address-spaces.ll
@@ -0,0 +1,25 @@
+; RUN: opt -lint < %s
+
+target datalayout = "p32:32:32-p1:16:16:16-n16:32"
+
+declare void @foo(i64) nounwind
+
+define i64 @test1(i32 addrspace(1)* %x) nounwind {
+  %y = ptrtoint i32 addrspace(1)* %x to i64
+  ret i64 %y
+}
+
+define <4 x i64> @test1_vector(<4 x i32 addrspace(1)*> %x) nounwind {
+  %y = ptrtoint <4 x i32 addrspace(1)*> %x to <4 x i64>
+  ret <4 x i64> %y
+}
+
+define i32 addrspace(1)* @test2(i64 %x) nounwind {
+  %y = inttoptr i64 %x to i32 addrspace(1)*
+  ret i32 addrspace(1)* %y
+}
+
+define <4 x i32 addrspace(1)*> @test2_vector(<4 x i64> %x) nounwind {
+  %y = inttoptr <4 x i64> %x to <4 x i32 addrspace(1)*>
+  ret <4 x i32 addrspace(1)*> %y
+}
\ No newline at end of file