- Avoid using floating point stores to implement memset unless the value is zero.

- Do not try to infer GV alignment unless its type is sized. It's not possible to infer alignment if it has opaque type.

llvm-svn: 100118

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index bd268eca8f5..5d6e571db12 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -1076,6 +1076,7 @@ unsigned X86TargetLowering::getByValTypeAlignment(const Type *Ty) const {
 EVT
 X86TargetLowering::getOptimalMemOpType(uint64_t Size,
                                        unsigned DstAlign, unsigned SrcAlign,
+                                       bool SafeToUseFP,
                                        SelectionDAG &DAG) const {
   // FIXME: This turns off use of xmm stores for memset/memcpy on targets like
   // linux.  This is because the stack realignment code can't handle certain
@@ -1089,9 +1090,10 @@ X86TargetLowering::getOptimalMemOpType(uint64_t Size,
         Subtarget->getStackAlignment() >= 16) {
       if (Subtarget->hasSSE2())
         return MVT::v4i32;
-      if (Subtarget->hasSSE1())
+      if (SafeToUseFP && Subtarget->hasSSE1())
         return MVT::v4f32;
-    } else if (Size >= 8 &&
+    } else if (SafeToUseFP &&
+               Size >= 8 &&
                Subtarget->getStackAlignment() >= 8 &&
                Subtarget->hasSSE2())
       return MVT::f64;