[llvm-commits] [llvm] r51850 - in /llvm/trunk: lib/Transforms/Scalar/MemCpyOptimizer.cpp test/Transforms/MemCpyOpt/2008-06-01-MemCpy-MemMove.ll

[Owen Anderson]

Author: resistor
Date: Sun Jun  1 17:26:26 2008
New Revision: 51850

URL: http://llvm.org/viewvc/llvm-project?rev=51850&view=rev
Log:
Fix two issues that Eli Friedman pointed out, where would misoptimized code like:

char a[200];
init(a, a+200);

OR

int a[200];
char* b = (char*)a;
char* c = (char*)a;
foo(b, c);

Modified:
    llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
    llvm/trunk/test/Transforms/MemCpyOpt/2008-06-01-MemCpy-MemMove.ll

Modified: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=51850&r1=51849&r2=51850&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Sun Jun  1 17:26:26 2008
@@ -554,10 +554,17 @@
     User* UI = srcUseList.back();
     srcUseList.pop_back();
 
-    if (isa<GetElementPtrInst>(UI) || isa<BitCastInst>(UI)) {
+    if (isa<BitCastInst>(UI)) {
       for (User::use_iterator I = UI->use_begin(), E = UI->use_end();
            I != E; ++I)
         srcUseList.push_back(*I);
+    } else if (GetElementPtrInst* G = dyn_cast<GetElementPtrInst>(UI)) {
+      if (G->hasAllZeroIndices())
+        for (User::use_iterator I = UI->use_begin(), E = UI->use_end();
+             I != E; ++I)
+          srcUseList.push_back(*I);
+      else
+        return false;
     } else if (UI != C && UI != cpy) {
       return false;
     }
@@ -582,12 +589,16 @@
   // All the checks have passed, so do the transformation.
   bool changedArgument = false;
   for (unsigned i = 0; i < CS.arg_size(); ++i)
-    if (CS.getArgument(i) == cpySrc) {
+    if (CS.getArgument(i)->stripPointerCasts() == cpySrc) {
       if (cpySrc->getType() != cpyDest->getType())
         cpyDest = CastInst::CreatePointerCast(cpyDest, cpySrc->getType(),
                                               cpyDest->getName(), C);
       changedArgument = true;
-      CS.setArgument(i, cpyDest);
+      if (CS.getArgument(i)->getType() != cpyDest->getType())
+        CS.setArgument(i, CastInst::CreatePointerCast(cpyDest, 
+                       CS.getArgument(i)->getType(), cpyDest->getName(), C));
+      else
+        CS.setArgument(i, cpyDest);
     }
 
   if (!changedArgument)

Modified: llvm/trunk/test/Transforms/MemCpyOpt/2008-06-01-MemCpy-MemMove.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/2008-06-01-MemCpy-MemMove.ll?rev=51850&r1=51849&r2=51850&view=diff

==============================================================================
--- llvm/trunk/test/Transforms/MemCpyOpt/2008-06-01-MemCpy-MemMove.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/2008-06-01-MemCpy-MemMove.ll Sun Jun  1 17:26:26 2008
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -memcpyopt | llvm-dis | grep {call.*memcpy.*}
+; RUN: llvm-as < %s | opt -memcpyopt | llvm-dis | grep {call.*memmove.*arg1.*}
 ; PR2401
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"