add DEBUG and -stats output to earlycse.

Teach it to CSE the rest of the non-side-effecting instructions.

llvm-svn: 122716

2 files changed, 39 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Scalar/EarlyCSE.cpp b/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
index a43d4254c3a..862e37ca28e 100644
--- a/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
+++ b/llvm/lib/Transforms/Scalar/EarlyCSE.cpp
@@ -14,15 +14,21 @@
 
 #define DEBUG_TYPE "early-cse"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Instructions.h"
 #include "llvm/Pass.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/ADT/ScopedHashTable.h"
+#include "llvm/ADT/Statistic.h"
 using namespace llvm;
 
+STATISTIC(NumSimplify, "Number of insts simplified or DCE'd");
+STATISTIC(NumCSE, "Number of insts CSE'd");
+
 namespace {
   /// InstValue - Instances of this struct represent available values in the
   /// scoped hash table.
@@ -35,7 +41,11 @@ namespace {
     }
     
     static bool canHandle(Instruction *Inst) {
-      return isa<CastInst>(Inst);
+      return isa<CastInst>(Inst) || isa<BinaryOperator>(Inst) ||
+             isa<GetElementPtrInst>(Inst) || isa<CmpInst>(Inst) ||
+             isa<SelectInst>(Inst) || isa<ExtractElementInst>(Inst) ||
+             isa<InsertElementInst>(Inst) || isa<ShuffleVectorInst>(Inst) ||
+             isa<ExtractValueInst>(Inst) || isa<InsertValueInst>(Inst);
     }
     
     static InstValue get(Instruction *I) {
@@ -73,8 +83,24 @@ unsigned DenseMapInfo<InstValue>::getHashValue(InstValue Val) {
   unsigned Res = 0;
   if (CastInst *CI = dyn_cast<CastInst>(Inst))
     Res = getHash(CI->getOperand(0)) ^ getHash(CI->getType());
-  else
-    assert(0 && "Unhandled instruction kind");
+  else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Inst))
+    Res = getHash(BO->getOperand(0)) ^ (getHash(BO->getOperand(1)) << 1);
+  else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) {
+    Res = getHash(CI->getOperand(0));
+    for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i)
+      Res ^= getHash(CI->getOperand(i)) << i;
+  } else if (CmpInst *CI = dyn_cast<CmpInst>(Inst)) {
+      Res = getHash(CI->getOperand(0)) ^ (getHash(CI->getOperand(1)) << 1) ^
+         CI->getPredicate();
+  } else {
+    assert((isa<SelectInst>(Inst) || isa<ExtractElementInst>(Inst) ||
+            isa<InsertElementInst>(Inst) || isa<ShuffleVectorInst>(Inst) ||
+            isa<ExtractValueInst>(Inst) || isa<InsertValueInst>(Inst)) &&
+           "Unhandled instruction kind");
+    Res = getHash(CI->getType()) << 4;
+    for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i)
+      Res ^= getHash(CI->getOperand(i)) << i;
+  }
   
   return (Res << 1) ^ Inst->getOpcode();
 }
@@ -152,17 +178,21 @@ bool EarlyCSE::processNode(DomTreeNode *Node) {
     
     // Dead instructions should just be removed.
     if (isInstructionTriviallyDead(Inst)) {
+      DEBUG(dbgs() << "EarlyCSE DCE: " << *Inst << '\n');
       Inst->eraseFromParent();
       Changed = true;
+      ++NumSimplify;
       continue;
     }
     
     // If the instruction can be simplified (e.g. X+0 = X) then replace it with
     // its simpler value.
     if (Value *V = SimplifyInstruction(Inst, TD, DT)) {
+      DEBUG(dbgs() << "EarlyCSE Simplify: " << *Inst << "  to: " << *V << '\n');
       Inst->replaceAllUsesWith(V);
       Inst->eraseFromParent();
       Changed = true;
+      ++NumSimplify;
       continue;
     }
     
@@ -172,9 +202,11 @@ bool EarlyCSE::processNode(DomTreeNode *Node) {
     
     // See if the instruction has an available value.  If so, use it.
     if (Instruction *V = AvailableValues->lookup(InstValue::get(Inst))) {
+      DEBUG(dbgs() << "EarlyCSE CSE: " << *Inst << "  to: " << *V << '\n');
       Inst->replaceAllUsesWith(V);
       Inst->eraseFromParent();
       Changed = true;
+      ++NumCSE;
       continue;
     }
     
diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index 49368cb7f7e..086afb14b29 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -31,7 +31,10 @@
 //   void foo(_Complex float *P)
 //     for (i) { __real__(*P) = 0;  __imag__(*P) = 0; }
 // this is also "Example 2" from http://blog.regehr.org/archives/320
-//  
+//
+// This could regognize common matrix multiplies and dot product idioms and
+// replace them with calls to BLAS (if linked in??).
+//
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "loop-idiom"
@@ -49,8 +52,6 @@
 #include "llvm/ADT/Statistic.h"
 using namespace llvm;
 
-// TODO: Recognize "N" size array multiplies: replace with call to blas or
-// something.
 STATISTIC(NumMemSet, "Number of memset's formed from loop stores");
 STATISTIC(NumMemCpy, "Number of memcpy's formed from loop load+stores");