Use a simpler (and more efficient) pattern to pad vectors.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150475 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 11 insertions, 19 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index ae4084ba6c..95bed1b0e6 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1181,11 +1181,9 @@ void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
       // FIXME: since we're shuffling with undef, can we just use the indices
       //        into that?  This could be simpler.
       SmallVector<llvm::Constant*, 4> ExtMask;
-      unsigned i;
-      for (i = 0; i != NumSrcElts; ++i)
+      for (unsigned i = 0; i != NumSrcElts; ++i)
         ExtMask.push_back(Builder.getInt32(i));
-      for (; i != NumDstElts; ++i)
-        ExtMask.push_back(llvm::UndefValue::get(Int32Ty));
+      ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
       llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
       llvm::Value *ExtSrcVal =
         Builder.CreateShuffleVector(SrcVal,
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index 0b3ac9cbe5..44531c0992 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -701,9 +701,9 @@ public:
     // Copy initializer elements.
     std::vector<llvm::Constant*> Elts;
     Elts.reserve(NumInitableElts + NumElements);
-    unsigned i = 0;
+
     bool RewriteType = false;
-    for (; i < NumInitableElts; ++i) {
+    for (unsigned i = 0; i < NumInitableElts; ++i) {
       Expr *Init = ILE->getInit(i);
       llvm::Constant *C = CGM.EmitConstantExpr(Init, Init->getType(), CGF);
       if (!C)
@@ -722,8 +722,7 @@ public:
     if (!fillC)
       return 0;
     RewriteType |= (fillC->getType() != ElemTy);
-    for (; i < NumElements; ++i)
-      Elts.push_back(fillC);
+    Elts.resize(NumElements, fillC);
 
     if (RewriteType) {
       // FIXME: Try to avoid packing the array
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 4047a39287..d9b0e21238 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -895,8 +895,7 @@ Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
           if (CurIdx == 0) {
             // insert into undef -> shuffle (src, undef)
             Args.push_back(C);
-            for (unsigned j = 1; j != ResElts; ++j)
-              Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
+            Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
 
             LHS = EI->getVectorOperand();
             RHS = V;
@@ -907,9 +906,8 @@ Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
             for (unsigned j = 0; j != CurIdx; ++j)
               Args.push_back(getMaskElt(SVV, j, 0, CGF.Int32Ty));
             Args.push_back(Builder.getInt32(ResElts + C->getZExtValue()));
-            for (unsigned j = CurIdx + 1; j != ResElts; ++j)
-              Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
-            
+            Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
+
             LHS = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
             RHS = EI->getVectorOperand();
             VIsUndefShuffle = false;
@@ -953,8 +951,7 @@ Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
         }
         for (unsigned j = 0, je = InitElts; j != je; ++j)
           Args.push_back(getMaskElt(SVI, j, Offset, CGF.Int32Ty));
-        for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
-          Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
+        Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
 
         if (VIsUndefShuffle)
           V = cast<llvm::ShuffleVectorInst>(V)->getOperand(0);
@@ -968,8 +965,7 @@ Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
     if (Args.empty()) {
       for (unsigned j = 0; j != InitElts; ++j)
         Args.push_back(Builder.getInt32(j));
-      for (unsigned j = InitElts; j != ResElts; ++j)
-        Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
+      Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
       llvm::Constant *Mask = llvm::ConstantVector::get(Args);
       Init = Builder.CreateShuffleVector(Init, llvm::UndefValue::get(VVT),
                                          Mask, "vext");
@@ -979,8 +975,7 @@ Value *ScalarExprEmitter::VisitInitListExpr(InitListExpr *E) {
         Args.push_back(Builder.getInt32(j));
       for (unsigned j = 0; j != InitElts; ++j)
         Args.push_back(Builder.getInt32(j+Offset));
-      for (unsigned j = CurIdx + InitElts; j != ResElts; ++j)
-        Args.push_back(llvm::UndefValue::get(CGF.Int32Ty));
+      Args.resize(ResElts, llvm::UndefValue::get(CGF.Int32Ty));
     }
 
     // If V is undef, make sure it ends up on the RHS of the shuffle to aid