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.

llvm-svn: 169959

2 files changed, 12 insertions, 14 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index f87d1fcb88c..23301b60c22 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/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/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h
index 601ed2b1200..cbe83a7c244 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.h
+++ b/llvm/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