Make changes to rev 84292 as requested by Chris Lattner.

Most changes are cleanup, but there is 1 correctness fix:
I fixed InstCombine so that the icmp is removed only if the malloc call is removed (which requires explicit removal because the Worklist won't DCE any calls since they can have side-effects).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84772 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 47 insertions, 35 deletions

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index f1d5e4ffbb..d21f98707f 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -69,7 +69,7 @@ bool LLParser::Run() {
 /// ValidateEndOfModule - Do final validity and sanity checks at the end of the
 /// module.
 bool LLParser::ValidateEndOfModule() {
-  // Update auto-upgraded malloc calls from "autoupgrade_malloc" to "malloc".
+  // Update auto-upgraded malloc calls to "malloc".
   // FIXME: Remove in LLVM 3.0.
   if (MallocF) {
     MallocF->setName("malloc");
@@ -77,15 +77,10 @@ bool LLParser::ValidateEndOfModule() {
     // declaration of "malloc".  In that case, iterate over all calls to MallocF
     // and get them to call the declared "malloc" instead.
     if (MallocF->getName() != "malloc") {
-      Function* realMallocF = M->getFunction("malloc");
-      for (User::use_iterator UI = MallocF->use_begin(), UE= MallocF->use_end();
-           UI != UE; ) {
-        User* user = *UI;
-        UI++;
-        if (CallInst *Call = dyn_cast<CallInst>(user))
-          Call->setCalledFunction(realMallocF);
-      }
-      if (!realMallocF->doesNotAlias(0)) realMallocF->setDoesNotAlias(0);
+      Constant* RealMallocF = M->getFunction("malloc");
+      if (RealMallocF->getType() != MallocF->getType())
+        RealMallocF = ConstantExpr::getBitCast(RealMallocF, MallocF->getType());
+      MallocF->replaceAllUsesWith(RealMallocF);
       MallocF->eraseFromParent();
       MallocF = NULL;
     }
@@ -3482,21 +3477,21 @@ bool LLParser::ParseAlloc(Instruction *&Inst, PerFunctionState &PFS,
   if (Size && Size->getType() != Type::getInt32Ty(Context))
     return Error(SizeLoc, "element count must be i32");
 
-  if (isAlloca)
+  if (isAlloca) {
     Inst = new AllocaInst(Ty, Size, Alignment);
-  else {
-    // Autoupgrade old malloc instruction to malloc call.
-    const Type* IntPtrTy = Type::getInt32Ty(Context);
-    const Type* Int8PtrTy = PointerType::getUnqual(Type::getInt8Ty(Context));
-    if (!MallocF)
-      // Prototype malloc as "void *autoupgrade_malloc(int32)".
-      MallocF = cast<Function>(M->getOrInsertFunction("autoupgrade_malloc",
-                               Int8PtrTy, IntPtrTy, NULL));
-      // "autoupgrade_malloc" updated to "malloc" in ValidateEndOfModule().
-
-    Inst = cast<Instruction>(CallInst::CreateMalloc(BB, IntPtrTy, Ty,
-                                                    Size, MallocF));
+    return false;
   }
+
+  // Autoupgrade old malloc instruction to malloc call.
+  // FIXME: Remove in LLVM 3.0.
+  const Type *IntPtrTy = Type::getInt32Ty(Context);
+  const Type *Int8PtrTy = Type::getInt8PtrTy(Context);
+  if (!MallocF)
+    // Prototype malloc as "void *(int32)".
+    // This function is renamed as "malloc" in ValidateEndOfModule().
+    MallocF = cast<Function>(M->getOrInsertFunction(NULL, Int8PtrTy, 
+                                                    IntPtrTy, NULL));
+  Inst = CallInst::CreateMalloc(BB, IntPtrTy, Ty, Size, MallocF);
   return false;
 }
 
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index fe4556f0a2..c9eba24b82 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2045,6 +2045,7 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
 
     case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
       // Autoupgrade malloc instruction to malloc call.
+      // FIXME: Remove in LLVM 3.0.
       if (Record.size() < 3)
         return Error("Invalid MALLOC record");
       const PointerType *Ty =
@@ -2052,13 +2053,9 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
       Value *Size = getFnValueByID(Record[1], Type::getInt32Ty(Context));
       if (!Ty || !Size) return Error("Invalid MALLOC record");
       if (!CurBB) return Error("Invalid malloc instruction with no BB");
-      const Type* Int32Ty = IntegerType::getInt32Ty(CurBB->getContext());
-      if (Size->getType() != Int32Ty)
-        Size = CastInst::CreateIntegerCast(Size, Int32Ty, false /*ZExt*/,
-                                           "", CurBB);
-      Value* Malloc = CallInst::CreateMalloc(CurBB, Int32Ty,
-                                             Ty->getElementType(), Size, NULL);
-      I = cast<Instruction>(Malloc);
+      const Type *Int32Ty = IntegerType::getInt32Ty(CurBB->getContext());
+      I = CallInst::CreateMalloc(CurBB, Int32Ty, Ty->getElementType(),
+                                 Size, NULL);
       InstructionList.push_back(I);
       break;
     }
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 46fac196db..1088684b0a 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -6359,10 +6359,28 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
         // can assume it is successful and remove the malloc.
         if (isMalloc(LHSI) && LHSI->hasOneUse() &&
             isa<ConstantPointerNull>(RHSC)) {
-          Worklist.Add(LHSI);
-          return ReplaceInstUsesWith(I,
+          // Need to explicitly erase malloc call here, instead of adding it to
+          // Worklist, because it won't get DCE'd from the Worklist since
+          // isInstructionTriviallyDead() returns false for function calls.
+          // It is OK to replace LHSI/MallocCall with Undef because the 
+          // instruction that uses it will be erased via Worklist.
+          if (extractMallocCall(LHSI)) {
+            LHSI->replaceAllUsesWith(UndefValue::get(LHSI->getType()));
+            EraseInstFromFunction(*LHSI);
+            return ReplaceInstUsesWith(I,
                                      ConstantInt::get(Type::getInt1Ty(*Context),
                                                       !I.isTrueWhenEqual()));
+          }
+          if (CallInst* MallocCall = extractMallocCallFromBitCast(LHSI))
+            if (MallocCall->hasOneUse()) {
+              MallocCall->replaceAllUsesWith(
+                                        UndefValue::get(MallocCall->getType()));
+              EraseInstFromFunction(*MallocCall);
+              Worklist.Add(LHSI); // The malloc's bitcast use.
+              return ReplaceInstUsesWith(I,
+                                     ConstantInt::get(Type::getInt1Ty(*Context),
+                                                      !I.isTrueWhenEqual()));
+            }
         }
         break;
       }
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 00d450812c..af29f97808 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -29,7 +29,6 @@
 #include "llvm/IntrinsicInst.h"
 #include "llvm/LLVMContext.h"
 #include "llvm/Pass.h"
-#include "llvm/Analysis/MallocHelper.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/Debug.h"
@@ -122,7 +121,6 @@ static bool isUnmovableInstruction(Instruction *I) {
   if (I->getOpcode() == Instruction::PHI ||
       I->getOpcode() == Instruction::Alloca ||
       I->getOpcode() == Instruction::Load ||
-      isMalloc(I) ||
       I->getOpcode() == Instruction::Invoke ||
       (I->getOpcode() == Instruction::Call &&
        !isa<DbgInfoIntrinsic>(I)) ||
diff --git a/test/Transforms/InstCombine/malloc2.ll b/test/Transforms/InstCombine/malloc2.ll
index cc1506b6b1..8462dacf85 100644
--- a/test/Transforms/InstCombine/malloc2.ll
+++ b/test/Transforms/InstCombine/malloc2.ll
@@ -1,18 +1,22 @@
-; RUN: opt < %s -instcombine -S | grep {ret i32 0}
+; RUN: opt < %s -instcombine -S | FileCheck %s
 ; PR1313
 
 define i32 @test1(i32 %argc, i8* %argv, i8* %envp) {
         %tmp15.i.i.i23 = malloc [2564 x i32]            ; <[2564 x i32]*> [#uses=1]
+; CHECK-NOT: call i8* @malloc
         %c = icmp eq [2564 x i32]* %tmp15.i.i.i23, null              ; <i1>:0 [#uses=1]
         %retval = zext i1 %c to i32             ; <i32> [#uses=1]
         ret i32 %retval
+; CHECK: ret i32 0
 }
 
 define i32 @test2(i32 %argc, i8* %argv, i8* %envp) {
         %tmp15.i.i.i23 = malloc [2564 x i32]            ; <[2564 x i32]*> [#uses=1]
+; CHECK-NOT: call i8* @malloc
         %X = bitcast [2564 x i32]* %tmp15.i.i.i23 to i32*
         %c = icmp ne i32* %X, null
         %retval = zext i1 %c to i32             ; <i32> [#uses=1]
         ret i32 %retval
+; CHECK: ret i32 1
 }