Add stubs for setcc-branch folding support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18818 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 0 deletions

diff --git a/lib/Target/Sparc/SparcV8ISelSimple.cpp b/lib/Target/Sparc/SparcV8ISelSimple.cpp
index 5959c47afd..68bc28a0f3 100644
--- a/lib/Target/Sparc/SparcV8ISelSimple.cpp
+++ b/lib/Target/Sparc/SparcV8ISelSimple.cpp
@@ -1010,6 +1010,14 @@ static inline BasicBlock *getBlockAfter(BasicBlock *BB) {
   return I != BB->getParent()->end() ? &*I : 0;
 }
 
+/// canFoldSetCCIntoBranch - Return the setcc instruction if we can fold it
+/// into the conditional branch which is the only user of the cc instruction.
+/// This is the case if the conditional branch is the only user of the setcc.
+///
+static SetCondInst *canFoldSetCCIntoBranch(Value *V) {
+  return 0; // disable.
+}
+
 /// visitBranchInst - Handles conditional and unconditional branches.
 ///
 void V8ISel::visitBranchInst(BranchInst &I) {
@@ -1480,6 +1488,9 @@ void V8ISel::visitBinaryOperator (Instruction &I) {
 }
 
 void V8ISel::visitSetCondInst(SetCondInst &I) {
+  if (canFoldSetCCIntoBranch(&I))
+    return;  // Fold this into a branch.
+
   unsigned Op0Reg = getReg (I.getOperand (0));
   unsigned Op1Reg = getReg (I.getOperand (1));
   unsigned DestReg = getReg (I);
diff --git a/lib/Target/SparcV8/SparcV8ISelSimple.cpp b/lib/Target/SparcV8/SparcV8ISelSimple.cpp
index 5959c47afd..68bc28a0f3 100644
--- a/lib/Target/SparcV8/SparcV8ISelSimple.cpp
+++ b/lib/Target/SparcV8/SparcV8ISelSimple.cpp
@@ -1010,6 +1010,14 @@ static inline BasicBlock *getBlockAfter(BasicBlock *BB) {
   return I != BB->getParent()->end() ? &*I : 0;
 }
 
+/// canFoldSetCCIntoBranch - Return the setcc instruction if we can fold it
+/// into the conditional branch which is the only user of the cc instruction.
+/// This is the case if the conditional branch is the only user of the setcc.
+///
+static SetCondInst *canFoldSetCCIntoBranch(Value *V) {
+  return 0; // disable.
+}
+
 /// visitBranchInst - Handles conditional and unconditional branches.
 ///
 void V8ISel::visitBranchInst(BranchInst &I) {
@@ -1480,6 +1488,9 @@ void V8ISel::visitBinaryOperator (Instruction &I) {
 }
 
 void V8ISel::visitSetCondInst(SetCondInst &I) {
+  if (canFoldSetCCIntoBranch(&I))
+    return;  // Fold this into a branch.
+
   unsigned Op0Reg = getReg (I.getOperand (0));
   unsigned Op1Reg = getReg (I.getOperand (1));
   unsigned DestReg = getReg (I);