Sorry about the churn. One more change to getOptimalMemOpType() hook. Did I

mention the inline memcpy / memset expansion code is a mess?

This patch split the ZeroOrLdSrc argument into two: IsMemset and ZeroMemset.
The first indicates whether it is expanding a memset or a memcpy / memmove.
The later is whether the memset is a memset of zero. It's totally possible
(likely even) that targets may want to do different things for memcpy and
memset of zero.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169959 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 43 insertions, 44 deletions

diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 3adf517..6c88261 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -701,16 +701,16 @@ public:
   /// lowering. If DstAlign is zero that means it's safe to destination
   /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
   /// means there isn't a need to check it against alignment requirement,
-  /// probably because the source does not need to be loaded. If
-  /// 'ZeroOrLdSrc' is true, that means it's safe to return a
-  /// non-scalar-integer type, e.g. empty string source, constant, or loaded
-  /// from memory. 'MemcpyStrSrc' indicates whether the memcpy source is
-  /// constant so it does not need to be loaded.
+  /// probably because the source does not need to be loaded. If 'IsMemset' is
+  /// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
+  /// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
+  /// source is constant so it does not need to be loaded.
   /// It returns EVT::Other if the type should be determined using generic
   /// target-independent logic.
   virtual EVT getOptimalMemOpType(uint64_t /*Size*/,
                                   unsigned /*DstAlign*/, unsigned /*SrcAlign*/,
-                                  bool /*ZeroOrLdSrc*/,
+                                  bool /*IsMemset*/,
+                                  bool /*ZeroMemset*/,
                                   bool /*MemcpyStrSrc*/,
                                   MachineFunction &/*MF*/) const {
     return MVT::Other;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 754e6f35..269f221 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3426,7 +3426,8 @@ static bool isMemSrcFromString(SDValue Src, StringRef &Str) {
 static bool FindOptimalMemOpLowering(std::vector<EVT> &MemOps,
                                      unsigned Limit, uint64_t Size,
                                      unsigned DstAlign, unsigned SrcAlign,
-                                     bool ZeroOrLdSrc,
+                                     bool IsMemset,
+                                     bool ZeroMemset,
                                      bool MemcpyStrSrc,
                                      bool AllowOverlap,
                                      SelectionDAG &DAG,
@@ -3441,7 +3442,7 @@ static bool FindOptimalMemOpLowering(std::vector<EVT> &MemOps,
   // 'MemcpyStrSrc' indicates whether the memcpy source is constant so it does
   // not need to be loaded.
   EVT VT = TLI.getOptimalMemOpType(Size, DstAlign, SrcAlign,
-                                   ZeroOrLdSrc, MemcpyStrSrc,
+                                   IsMemset, ZeroMemset, MemcpyStrSrc,
                                    DAG.getMachineFunction());
 
   if (VT == MVT::Other) {
@@ -3559,7 +3560,7 @@ static SDValue getMemcpyLoadsAndStores(SelectionDAG &DAG, DebugLoc dl,
   if (!FindOptimalMemOpLowering(MemOps, Limit, Size,
                                 (DstAlignCanChange ? 0 : Align),
                                 (isZeroStr ? 0 : SrcAlign),
-                                true, CopyFromStr, true, DAG, TLI))
+                                false, false, CopyFromStr, true, DAG, TLI))
     return SDValue();
 
   if (DstAlignCanChange) {
@@ -3660,8 +3661,8 @@ static SDValue getMemmoveLoadsAndStores(SelectionDAG &DAG, DebugLoc dl,
   unsigned Limit = AlwaysInline ? ~0U : TLI.getMaxStoresPerMemmove(OptSize);
 
   if (!FindOptimalMemOpLowering(MemOps, Limit, Size,
-                                (DstAlignCanChange ? 0 : Align),
-                                SrcAlign, true, false, false, DAG, TLI))
+                                (DstAlignCanChange ? 0 : Align), SrcAlign,
+                                false, false, false, false, DAG, TLI))
     return SDValue();
 
   if (DstAlignCanChange) {
@@ -3737,7 +3738,7 @@ static SDValue getMemsetStores(SelectionDAG &DAG, DebugLoc dl,
     isa<ConstantSDNode>(Src) && cast<ConstantSDNode>(Src)->isNullValue();
   if (!FindOptimalMemOpLowering(MemOps, TLI.getMaxStoresPerMemset(OptSize),
                                 Size, (DstAlignCanChange ? 0 : Align), 0,
-                                IsZeroVal, false, true, DAG, TLI))
+                                true, IsZeroVal, false, true, DAG, TLI))
     return SDValue();
 
   if (DstAlignCanChange) {
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 613df7a..b0c81ca 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -9450,13 +9450,13 @@ static bool memOpAlign(unsigned DstAlign, unsigned SrcAlign,
 
 EVT ARMTargetLowering::getOptimalMemOpType(uint64_t Size,
                                            unsigned DstAlign, unsigned SrcAlign,
-                                           bool ZeroOrLdSrc,
+                                           bool IsMemset, bool ZeroMemset,
                                            bool MemcpyStrSrc,
                                            MachineFunction &MF) const {
   const Function *F = MF.getFunction();
 
   // See if we can use NEON instructions for this...
-  if (ZeroOrLdSrc &&
+  if ((!IsMemset || ZeroMemset) &&
       Subtarget->hasNEON() &&
       !F->getFnAttributes().hasAttribute(Attributes::NoImplicitFloat)) {
     bool Fast;
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index 59e2fd3..4c8bd0e 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -292,7 +292,7 @@ namespace llvm {
 
     virtual EVT getOptimalMemOpType(uint64_t Size,
                                     unsigned DstAlign, unsigned SrcAlign,
-                                    bool ZeroOrLdSrc,
+                                    bool IsMemset, bool ZeroMemset,
                                     bool MemcpyStrSrc,
                                     MachineFunction &MF) const;
 
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 5edf82b..65b33c1 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -3476,7 +3476,8 @@ MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
 }
 
 EVT MipsTargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
-                                            unsigned SrcAlign, bool ZeroOrLdSrc,
+                                            unsigned SrcAlign,
+                                            bool IsMemset, bool ZeroMemset,
                                             bool MemcpyStrSrc,
                                             MachineFunction &MF) const {
   if (Subtarget->hasMips64())
diff --git a/lib/Target/Mips/MipsISelLowering.h b/lib/Target/Mips/MipsISelLowering.h
index 4698661..ff25df9 100644
--- a/lib/Target/Mips/MipsISelLowering.h
+++ b/lib/Target/Mips/MipsISelLowering.h
@@ -362,7 +362,8 @@ namespace llvm {
     virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
 
     virtual EVT getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
-                                    unsigned SrcAlign, bool ZeroOrLdSrc,
+                                    unsigned SrcAlign,
+                                    bool IsMemset, bool ZeroMemset,
                                     bool MemcpyStrSrc,
                                     MachineFunction &MF) const;
 
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 59aaf6d..1402718 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -6814,16 +6814,15 @@ PPCTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
 /// lowering. If DstAlign is zero that means it's safe to destination
 /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
 /// means there isn't a need to check it against alignment requirement,
-/// probably because the source does not need to be loaded. If
-/// 'ZeroOrLdSrc' is true, that means it's safe to return a
-/// non-scalar-integer type, e.g. empty string source, constant, or loaded
-/// from memory. 'MemcpyStrSrc' indicates whether the memcpy source is
-/// constant so it does not need to be loaded.
+/// probably because the source does not need to be loaded. If 'IsMemset' is
+/// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
+/// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
+/// source is constant so it does not need to be loaded.
 /// It returns EVT::Other if the type should be determined using generic
 /// target-independent logic.
 EVT PPCTargetLowering::getOptimalMemOpType(uint64_t Size,
                                            unsigned DstAlign, unsigned SrcAlign,
-                                           bool ZeroOrLdSrc,
+                                           bool IsMemset, bool ZeroMemset,
                                            bool MemcpyStrSrc,
                                            MachineFunction &MF) const {
   if (this->PPCSubTarget.isPPC64()) {
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index a90118d..4b44dbc 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -400,16 +400,15 @@ namespace llvm {
     /// lowering. If DstAlign is zero that means it's safe to destination
     /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
     /// means there isn't a need to check it against alignment requirement,
-    /// probably because the source does not need to be loaded. If
-    /// 'ZeroOrLdSrc' is true, that means it's safe to return a
-    /// non-scalar-integer type, e.g. empty string source, constant, or loaded
-    /// from memory. 'MemcpyStrSrc' indicates whether the memcpy source is
-    /// constant so it does not need to be loaded.
+    /// probably because the source does not need to be loaded. If 'IsMemset' is
+    /// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
+    /// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
+    /// source is constant so it does not need to be loaded.
     /// It returns EVT::Other if the type should be determined using generic
     /// target-independent logic.
     virtual EVT
-    getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
-                        bool ZeroOrLdSrc, bool MemcpyStrSrc,
+    getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign, 
+                        bool IsMemset, bool ZeroMemset, bool MemcpyStrSrc,
                         MachineFunction &MF) const;
 
     /// isFMAFasterThanMulAndAdd - Return true if an FMA operation is faster than
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index f87d1fc..23301b6 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1369,21 +1369,20 @@ unsigned X86TargetLowering::getByValTypeAlignment(Type *Ty) const {
 /// lowering. If DstAlign is zero that means it's safe to destination
 /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
 /// means there isn't a need to check it against alignment requirement,
-/// probably because the source does not need to be loaded. If
-/// 'ZeroOrLdSrc' is true, that means it's safe to return a
-/// non-scalar-integer type, e.g. empty string source, constant, or loaded
-/// from memory. 'MemcpyStrSrc' indicates whether the memcpy source is
-/// constant so it does not need to be loaded.
+/// probably because the source does not need to be loaded. If 'IsMemset' is
+/// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
+/// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
+/// source is constant so it does not need to be loaded.
 /// It returns EVT::Other if the type should be determined using generic
 /// target-independent logic.
 EVT
 X86TargetLowering::getOptimalMemOpType(uint64_t Size,
                                        unsigned DstAlign, unsigned SrcAlign,
-                                       bool ZeroOrLdSrc,
+                                       bool IsMemset, bool ZeroMemset,
                                        bool MemcpyStrSrc,
                                        MachineFunction &MF) const {
   const Function *F = MF.getFunction();
-  if (ZeroOrLdSrc &&
+  if ((!IsMemset || ZeroMemset) &&
       !F->getFnAttributes().hasAttribute(Attributes::NoImplicitFloat)) {
     if (Size >= 16 &&
         (Subtarget->isUnalignedMemAccessFast() ||
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 601ed2b..cbe83a7 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -494,16 +494,15 @@ namespace llvm {
     /// lowering. If DstAlign is zero that means it's safe to destination
     /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
     /// means there isn't a need to check it against alignment requirement,
-    /// probably because the source does not need to be loaded. If
-    /// 'ZeroOrLdSrc' is true, that means it's safe to return a
-    /// non-scalar-integer type, e.g. empty string source, constant, or loaded
-    /// from memory. 'MemcpyStrSrc' indicates whether the memcpy source is
-    /// constant so it does not need to be loaded.
+    /// probably because the source does not need to be loaded. If 'IsMemset' is
+    /// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
+    /// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
+    /// source is constant so it does not need to be loaded.
     /// It returns EVT::Other if the type should be determined using generic
     /// target-independent logic.
     virtual EVT
-    getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
-                        bool ZeroOrLdSrc, bool MemcpyStrSrc,
+    getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign, 
+                        bool IsMemset, bool ZeroMemset, bool MemcpyStrSrc,
                         MachineFunction &MF) const;
 
     /// isSafeMemOpType - Returns true if it's safe to use load / store of the