Add support for GR32 <-> FR32 cross class copies.

We already support GR64 <-> VR128 copies.  All of these copies break
partial register dependencies by zeroing the high part of the target
register.

llvm-svn: 140348

1 files changed, 11 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 03471c73973..614202c2d56 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -2158,6 +2158,17 @@ static unsigned CopyToFromAsymmetricReg(unsigned DestReg, unsigned SrcReg,
       return X86::MOV64toSDrr;
   }
 
+  // SrcReg(FR32) -> DestReg(GR32)
+  // SrcReg(GR32) -> DestReg(FR32)
+
+  if (X86::GR32RegClass.contains(DestReg) && X86::FR32RegClass.contains(SrcReg))
+      // Copy from a FR32 register to a GR32 register.
+      return HasAVX ? X86::VMOVSS2DIrr : X86::MOVSS2DIrr;
+
+  if (X86::FR32RegClass.contains(DestReg) && X86::GR32RegClass.contains(SrcReg))
+      // Copy from a GR32 register to a FR32 register.
+      return HasAVX ? X86::VMOVDI2SSrr : X86::MOVDI2SSrr;
+
   return 0;
 }