[RISCV] Remove some unneeded widening FP vector pseudo instructions. NFC

[craig.topper]

Summary

We don't need LMUL=8 versions of these.

[michaelmaitland]

llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td

131–133

Consider refactoring into class MxSetW<int eew>, since we are doing it for MxSet<int eew>.

[craig.topper]

llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td

131–133

I think the other is used in multiple places. Adding another didn't seem worth the overhead.

[michaelmaitland]

LGTM

llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td

 
 class MxSet<int eew> {
   list<LMULInfo> m = !cond(!eq(eew, 8) : [V_MF8, V_MF4, V_MF2, V_M1, V_M2, V_M4, V_M8],
                            !eq(eew, 16) : [V_MF4, V_MF2, V_M1, V_M2, V_M4, V_M8],
                            !eq(eew, 32) : [V_MF2, V_M1, V_M2, V_M4, V_M8],
                            !eq(eew, 64) : [V_M1, V_M2, V_M4, V_M8]);
 }
 
-class FPR_Info<RegisterClass regclass, string fx, list<LMULInfo> mxlist> {
+class FPR_Info<RegisterClass regclass, string fx, list<LMULInfo> mxlist,
+               list<LMULInfo> mxlistfw> {
   RegisterClass fprclass = regclass;
   string FX = fx;
   list<LMULInfo> MxList = mxlist;
+  list<LMULInfo> MxListFW = mxlistfw;
 }
 
-def SCALAR_F16 : FPR_Info<FPR16, "F16", MxSet<16>.m>;
-def SCALAR_F32 : FPR_Info<FPR32, "F32", MxSet<32>.m>;
-def SCALAR_F64 : FPR_Info<FPR64, "F64", MxSet<64>.m>;
+def SCALAR_F16 : FPR_Info<FPR16, "F16", MxSet<16>.m, [V_MF4, V_MF2, V_M1, V_M2, V_M4]>;
+def SCALAR_F32 : FPR_Info<FPR32, "F32", MxSet<32>.m, [V_MF2, V_M1, V_M2, V_M4]>;
+def SCALAR_F64 : FPR_Info<FPR64, "F64", MxSet<64>.m, []>;
 
 defvar FPList = [SCALAR_F16, SCALAR_F32, SCALAR_F64];
 
 // Used for widening instructions. It excludes F64.
 defvar FPListW = [SCALAR_F16, SCALAR_F32];
 
 class NFSet<LMULInfo m> {
   list<int> L = !cond(!eq(m.value, V_M8.value): [],

 
 multiclass VPseudoBinaryW_VX_LMUL<LMULInfo m> {
   defm "_VX" : VPseudoBinary<m.wvrclass, m.vrclass, GPR, m,
                              "@earlyclobber $rd">;
 }
 
 multiclass VPseudoBinaryW_VF {
   foreach f = FPListW in
-    foreach m = f.MxList in
+    foreach m = f.MxListFW in
       defm "_V" # f.FX : VPseudoBinary<m.wvrclass, m.vrclass,
                                        f.fprclass, m,
                                        "@earlyclobber $rd">;
 }
 
 multiclass VPseudoBinaryW_WV<list<LMULInfo> mxlist = MxListW> {
   foreach m = mxlist in {
     defm _WV : VPseudoBinary<m.wvrclass, m.wvrclass, m.vrclass, m,

 }
 
 multiclass VPseudoBinaryW_WX_LMUL<LMULInfo m> {
   defm "_WX" : VPseudoBinary<m.wvrclass, m.wvrclass, GPR, m>;
 }
 
 multiclass VPseudoBinaryW_WF {
   foreach f = FPListW in
-    foreach m = f.MxList in
+    foreach m = f.MxListFW in
       defm "_W" # f.FX : VPseudoBinary<m.wvrclass, m.wvrclass,
                                        f.fprclass, m>;
 }
 
 // Narrowing instructions like vnsrl/vnsra/vnclip(u) don't need @earlyclobber
 // if the source and destination have an LMUL<=1. This matches this overlap
 // exception from the spec.
 // "The destination EEW is smaller than the source EEW and the overlap is in the
multiclass VPseudoTernaryW_VX<LMULInfo m> {
   defvar constraint = "@earlyclobber $rd";
   defm "_VX" : VPseudoTernaryWithPolicy<m.wvrclass, GPR, m.vrclass, m,
                                         constraint>;
 }
 
 multiclass VPseudoTernaryW_VF {
   defvar constraint = "@earlyclobber $rd";
   foreach f = FPListW in
-    foreach m = f.MxList in
+    foreach m = f.MxListFW in
       defm "_V" # f.FX : VPseudoTernaryWithPolicy<m.wvrclass, f.fprclass,
                                                   m.vrclass, m, constraint>;
 }
 
 multiclass VPseudoVSLDV_VI<Operand ImmType = simm5, string Constraint = ""> {
   foreach m = MxList in
     defm _VI : VPseudoTernaryWithPolicy<m.vrclass, m.vrclass, ImmType, m, Constraint>;
 }