Add support for VSX FMA single-precision instructions to the PPC back end

This patch corresponds to review:
http://reviews.llvm.org/D9941

It adds the various FMA instructions introduced in the version 2.07 of
the ISA along with the testing for them. These are operations on single
precision scalar values in VSX registers.

llvm-svn: 238578

1 files changed, 18 insertions, 9 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCFastISel.cpp b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
index 0b8e23c4ebf..a561d5b1190 100644
--- a/llvm/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
@@ -148,6 +148,9 @@ class PPCFastISel final : public FastISel {
     bool isVSFRCRegister(unsigned Register) const {
       return MRI.getRegClass(Register)->getID() == PPC::VSFRCRegClassID;
     }
+    bool isVSSRCRegister(unsigned Register) const {
+      return MRI.getRegClass(Register)->getID() == PPC::VSSRCRegClassID;
+    }
     bool PPCEmitCmp(const Value *Src1Value, const Value *Src2Value,
                     bool isZExt, unsigned DestReg);
     bool PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
@@ -503,8 +506,11 @@ bool PPCFastISel::PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
 
   // If this is a potential VSX load with an offset of 0, a VSX indexed load can
   // be used.
+  bool IsVSSRC = (ResultReg != 0) && isVSSRCRegister(ResultReg);
   bool IsVSFRC = (ResultReg != 0) && isVSFRCRegister(ResultReg);
-  if (IsVSFRC && (Opc == PPC::LFD) && 
+  bool Is32VSXLoad = IsVSSRC && Opc == PPC::LFS;
+  bool Is64VSXLoad = IsVSSRC && Opc == PPC::LFD;
+  if ((Is32VSXLoad || Is64VSXLoad) &&
       (Addr.BaseType != Address::FrameIndexBase) && UseOffset &&
       (Addr.Offset == 0)) {
     UseOffset = false;
@@ -518,7 +524,7 @@ bool PPCFastISel::PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
   // into a RegBase.
   if (Addr.BaseType == Address::FrameIndexBase) {
     // VSX only provides an indexed load.
-    if (IsVSFRC && Opc == PPC::LFD) return false;
+    if (Is32VSXLoad || Is64VSXLoad) return false;
 
     MachineMemOperand *MMO =
       FuncInfo.MF->getMachineMemOperand(
@@ -532,7 +538,7 @@ bool PPCFastISel::PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
   // Base reg with offset in range.
   } else if (UseOffset) {
     // VSX only provides an indexed load.
-    if (IsVSFRC && Opc == PPC::LFD) return false;
+    if (Is32VSXLoad || Is64VSXLoad) return false;
 
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
       .addImm(Addr.Offset).addReg(Addr.Base.Reg);
@@ -555,7 +561,7 @@ bool PPCFastISel::PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
       case PPC::LWA:    Opc = PPC::LWAX;    break;
       case PPC::LWA_32: Opc = PPC::LWAX_32; break;
       case PPC::LD:     Opc = PPC::LDX;     break;
-      case PPC::LFS:    Opc = PPC::LFSX;    break;
+      case PPC::LFS:    Opc = IsVSSRC ? PPC::LXSSPX : PPC::LFSX; break;
       case PPC::LFD:    Opc = IsVSFRC ? PPC::LXSDX : PPC::LFDX; break;
     }
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
@@ -636,9 +642,12 @@ bool PPCFastISel::PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr) {
 
   // If this is a potential VSX store with an offset of 0, a VSX indexed store
   // can be used.
+  bool IsVSSRC = isVSSRCRegister(SrcReg);
   bool IsVSFRC = isVSFRCRegister(SrcReg);
-  if (IsVSFRC && (Opc == PPC::STFD) && 
-      (Addr.BaseType != Address::FrameIndexBase) && UseOffset && 
+  bool Is32VSXStore = IsVSSRC && Opc == PPC::STFS;
+  bool Is64VSXStore = IsVSFRC && Opc == PPC::STFD;
+  if ((Is32VSXStore || Is64VSXStore) &&
+      (Addr.BaseType != Address::FrameIndexBase) && UseOffset &&
       (Addr.Offset == 0)) {
     UseOffset = false;
   }
@@ -648,7 +657,7 @@ bool PPCFastISel::PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr) {
   // into a RegBase.
   if (Addr.BaseType == Address::FrameIndexBase) {
     // VSX only provides an indexed store.
-    if (IsVSFRC && Opc == PPC::STFD) return false;
+    if (Is32VSXStore || Is64VSXStore) return false;
 
     MachineMemOperand *MMO =
       FuncInfo.MF->getMachineMemOperand(
@@ -665,7 +674,7 @@ bool PPCFastISel::PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr) {
   // Base reg with offset in range.
   } else if (UseOffset) {
     // VSX only provides an indexed store.
-    if (IsVSFRC && Opc == PPC::STFD) return false;
+    if (Is32VSXStore || Is64VSXStore) return false;
     
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc))
       .addReg(SrcReg).addImm(Addr.Offset).addReg(Addr.Base.Reg);
@@ -684,7 +693,7 @@ bool PPCFastISel::PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr) {
       case PPC::STH8: Opc = PPC::STHX8; break;
       case PPC::STW8: Opc = PPC::STWX8; break;
       case PPC::STD:  Opc = PPC::STDX;  break;
-      case PPC::STFS: Opc = PPC::STFSX; break;
+      case PPC::STFS: Opc = IsVSSRC ? PPC::STXSSPX : PPC::STFSX; break;
       case PPC::STFD: Opc = IsVSFRC ? PPC::STXSDX : PPC::STFDX; break;
     }