Fold code assuming MemToMemVarLenMacroOp::needsLoop is always true

* Remove the function MemToMemVarLenMacroOp::needsLoop() * Fold code that references it assuming it is always true Signed-off-by: Daryl Maier <maier@ca.ibm.com>
eclipse · Jun 14, 2019 · 7103275 · 7103275
1 parent 073acff
commit 7103275
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Showing 3 changed files with 12 additions and 17 deletions.
diff --git a/compiler/z/codegen/OMRTreeEvaluator.cpp b/compiler/z/codegen/OMRTreeEvaluator.cpp
@@ -9995,6 +9995,13 @@ OMR::Z::TreeEvaluator::BBEndEvaluator(TR::Node * node, TR::CodeGenerator * cg)
             }                                                         \
          }
 
+#define AlwaysClobberRegisterForLoops(evaluateChildren,baseAddr,baseReg) \
+         { if (evaluateChildren)                                      \
+            {                                                         \
+            baseReg = cg->gprClobberEvaluate(baseAddr);               \
+            }                                                         \
+         }
+
 ///////////////////////////////////////////////////////////////////////////////////////
 
 TR::Register *
@@ -11121,7 +11128,7 @@ OMR::Z::TreeEvaluator::arraysetEvaluator(TR::Node * node, TR::CodeGenerator * cg
          if (isZero)
             {
             MemClearVarLenMacroOp op(node, baseAddr, cg, elemsRegister, elemsExpr, lenMinusOne);
-            ClobberRegisterForLoops(evaluateChildren, op, baseAddr, baseReg);
+            AlwaysClobberRegisterForLoops(evaluateChildren, baseAddr, baseReg);
             op.setUseEXForRemainder(true);
             op.generate(baseReg);
             }
@@ -11130,14 +11137,14 @@ OMR::Z::TreeEvaluator::arraysetEvaluator(TR::Node * node, TR::CodeGenerator * cg
             if (useMVI)
                {
                MemInitVarLenMacroOp op(node, baseAddr, cg, elemsRegister, constExpr->getByte(), elemsExpr, lenMinusOne);
-               ClobberRegisterForLoops(evaluateChildren, op, baseAddr, baseReg);
+               AlwaysClobberRegisterForLoops(evaluateChildren, baseAddr, baseReg);
                op.setUseEXForRemainder(true);
                op.generate(baseReg);
                }
             else
                {
                MemInitVarLenMacroOp op(node, baseAddr, cg, elemsRegister, constExprRegister, elemsExpr, lenMinusOne);
-               ClobberRegisterForLoops(evaluateChildren, op, baseAddr, baseReg);
+               AlwaysClobberRegisterForLoops(evaluateChildren, baseAddr, baseReg);
                op.setUseEXForRemainder(true);
                op.generate(baseReg);
                }

diff --git a/compiler/z/codegen/OpMemToMem.cpp b/compiler/z/codegen/OpMemToMem.cpp
@@ -107,8 +107,6 @@ MemToMemVarLenMacroOp::generateLoop()
    if (getKind() == MemToMemMacroOp::IsMemInit)
       generateInstruction(0, 1);
 
-   if (!needsLoop()) return NULL;
-
    TR::LabelSymbol * topOfLoop = generateLabelSymbol(_cg);
    TR::LabelSymbol * bottomOfLoop = generateLabelSymbol(_cg);
 
@@ -195,11 +193,6 @@ MemToMemVarLenMacroOp::generateLoop()
 
    return cursor;
    }
-bool
-MemToMemVarLenMacroOp::needsLoop()
-   {
-   return true;
-   }
 
 TR::Instruction *
 MemToMemMacroOp::genSrcLoadAddress(int32_t offset, TR::Instruction *cursor)
@@ -978,7 +971,7 @@ MemToMemVarLenMacroOp::generateRemainder()
 
       TR::Instruction* cursor = NULL;
 
-      if (!TR::Compiler->target.cpu.getSupportsArch(TR::CPU::z10) || comp->getOption(TR_DisableInlineEXTarget) || !needsLoop())
+      if (!TR::Compiler->target.cpu.getSupportsArch(TR::CPU::z10) || comp->getOption(TR_DisableInlineEXTarget))
          {
          cursor = generateInstruction(0, 1);
          }
@@ -998,7 +991,7 @@ MemToMemVarLenMacroOp::generateRemainder()
         }
 
 
-      if (TR::Compiler->target.cpu.getSupportsArch(TR::CPU::z10) && !comp->getOption(TR_DisableInlineEXTarget) && needsLoop())
+      if (TR::Compiler->target.cpu.getSupportsArch(TR::CPU::z10) && !comp->getOption(TR_DisableInlineEXTarget))
          {
          TR_ASSERT(_EXTargetLabel != NULL, "Assert: EXTarget label must not be NULL");
 
@@ -1035,9 +1028,6 @@ MemToMemVarLenMacroOp::generateRemainder()
       _cursor = generateS390LabelInstruction(_cg, TR::InstOpCode::LABEL, _rootNode, remainderDoneLabel);
       }
 
-   if(!needsLoop() && _doneLabel==NULL)
-     _startControlFlow = _cursor; // If loop was not generated there is no need for control flow
-
    return _cursor;
    }
 

diff --git a/compiler/z/codegen/OpMemToMem.hpp b/compiler/z/codegen/OpMemToMem.hpp
@@ -297,8 +297,6 @@ class MemToMemConstLenMacroOp : public MemToMemMacroOp
 
 class MemToMemVarLenMacroOp : public MemToMemMacroOp
    {
-   public:
-      bool needsLoop();
    protected:
       MemToMemVarLenMacroOp(TR::Node* rootNode, TR::Node* dstNode, TR::Node* srcNode, TR::CodeGenerator * cg, TR::Register* regLen, TR::Node * lenNode, bool lengthMinusOne=false, TR::InstOpCode::Mnemonic opcode = TR::InstOpCode::MVC, TR::Register * itersReg = 0, TR::Register * raReg = 0)
          : MemToMemMacroOp(rootNode, dstNode, srcNode, cg, lenNode, itersReg), _regLen(regLen), _raReg(raReg), _doneLabel(0), _opcode(opcode), _lengthMinusOne(lengthMinusOne)