Merge pull request #6327 from Akira1Saitoh/aarch64SystemLinkageVectorReg

AArch64: Preserve vector registers across calls on system linkage
eclipse · Feb 3, 2022 · 96a484d · 96a484d
2 parents aea0efc + abc5a41
commit 96a484d
Show file tree

Hide file tree

Showing 3 changed files with 26 additions and 1 deletion.
diff --git a/compiler/aarch64/codegen/ARM64SystemLinkage.cpp b/compiler/aarch64/codegen/ARM64SystemLinkage.cpp
@@ -909,6 +909,14 @@ int32_t TR::ARM64SystemLinkage::buildArgs(TR::Node *callNode,
          }
       }
 
+   /* Spills all vector registers */
+   if (killsVectorRegisters())
+      {
+      TR::Register *tmpReg = cg()->allocateRegister();
+      dependencies->addPostCondition(tmpReg, TR::RealRegister::KillVectorRegs);
+      cg()->stopUsingRegister(tmpReg);
+      }
+
    if (numMemArgs > 0)
       {
       TR::RealRegister *sp = cg()->machine()->getRealRegister(properties.getStackPointerRegister());
@@ -935,10 +943,12 @@ TR::Register *TR::ARM64SystemLinkage::buildDirectDispatch(TR::Node *callNode)
    const TR::ARM64LinkageProperties &pp = getProperties();
    TR::RealRegister *sp = cg()->machine()->getRealRegister(pp.getStackPointerRegister());
 
+   // Extra post dependency for killing vector registers (see KillVectorRegs)
+   const int extraPostReg = killsVectorRegisters() ? 1 : 0;
    TR::RegisterDependencyConditions *dependencies =
       new (trHeapMemory()) TR::RegisterDependencyConditions(
          pp.getNumberOfDependencyGPRegisters(),
-         pp.getNumberOfDependencyGPRegisters(), trMemory());
+         pp.getNumberOfDependencyGPRegisters() + extraPostReg, trMemory());
 
    int32_t totalSize = buildArgs(callNode, dependencies);
    if (totalSize > 0)

diff --git a/compiler/aarch64/codegen/OMRLinkage.cpp b/compiler/aarch64/codegen/OMRLinkage.cpp
@@ -26,6 +26,7 @@
 #include "codegen/GenerateInstructions.hpp"
 #include "codegen/Linkage.hpp"
 #include "codegen/Linkage_inlines.hpp"
+#include "codegen/LiveRegister.hpp"
 #include "codegen/MemoryReference.hpp"
 #include "compile/Compilation.hpp"
 #include "il/Node.hpp"
@@ -409,3 +410,10 @@ TR::Instruction *OMR::ARM64::Linkage::copyParametersToHomeLocation(TR::Instructi
    //
    return loadCursor? loadCursor : cursor;
    }
+
+bool OMR::ARM64::Linkage::killsVectorRegisters()
+   {
+   // We need to kill vector registers if there is any live one.
+   TR_LiveRegisters *liveRegs = cg()->getLiveRegisters(TR_VRF);
+   return (!liveRegs || liveRegs->getNumberOfLiveRegisters() > 0);
+   }
diff --git a/compiler/aarch64/codegen/OMRLinkage.hpp b/compiler/aarch64/codegen/OMRLinkage.hpp
@@ -397,6 +397,13 @@ class OMR_EXTENSIBLE Linkage : public OMR::Linkage
     * @return The instruction cursor after copies inserted.
     */
    TR::Instruction *copyParametersToHomeLocation(TR::Instruction *cursor, bool parmsHaveBeenStored = false);
+
+   /**
+    * @brief Answers if vector registers need to be spilled
+    *
+    * @return true if vector registers need to be spilled.
+    */
+   bool killsVectorRegisters();
    };
 } // ARM64
 } // TR