[mips] Add madd4 subtarget feature

Addition of a feature and a predicate used to control generation of madd.fmt
and similar instructions.

Patch by Stefan Maksimovic.

Differential Revision: https://reviews.llvm.org/D33400

llvm-svn: 304801

5 files changed, 24 insertions, 10 deletions

diff --git a/llvm/lib/Target/Mips/Mips.td b/llvm/lib/Target/Mips/Mips.td
index 9615bc38bfc..f24761d7d10 100644
--- a/llvm/lib/Target/Mips/Mips.td
+++ b/llvm/lib/Target/Mips/Mips.td
@@ -185,6 +185,9 @@ def FeatureUseTCCInDIV : SubtargetFeature<
                                "UseTCCInDIV", "false",
                                "Force the assembler to use trapping">;
 
+def FeatureMadd4 : SubtargetFeature<"nomadd4", "DisableMadd4", "true",
+                                    "Disable 4-operand madd.fmt and related instructions">;
+
 //===----------------------------------------------------------------------===//
 // Mips processors supported.
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/Mips/MipsInstrFPU.td b/llvm/lib/Target/Mips/MipsInstrFPU.td
index d81a769d7fd..94f3a74be98 100644
--- a/llvm/lib/Target/Mips/MipsInstrFPU.td
+++ b/llvm/lib/Target/Mips/MipsInstrFPU.td
@@ -557,11 +557,11 @@ def FSUB_S : MMRel, ADDS_FT<"sub.s", FGR32Opnd, II_SUB_S, 0, fsub>,
 defm FSUB :  ADDS_M<"sub.d", II_SUB_D, 0, fsub>, ADDS_FM<0x01, 17>;
 
 def MADD_S : MMRel, MADDS_FT<"madd.s", FGR32Opnd, II_MADD_S, fadd>,
-             MADDS_FM<4, 0>, INSN_MIPS4_32R2_NOT_32R6_64R6;
+             MADDS_FM<4, 0>, INSN_MIPS4_32R2_NOT_32R6_64R6, MADD4;
 def MSUB_S : MMRel, MADDS_FT<"msub.s", FGR32Opnd, II_MSUB_S, fsub>,
-             MADDS_FM<5, 0>, INSN_MIPS4_32R2_NOT_32R6_64R6;
+             MADDS_FM<5, 0>, INSN_MIPS4_32R2_NOT_32R6_64R6, MADD4;
 
-let AdditionalPredicates = [NoNaNsFPMath] in {
+let AdditionalPredicates = [NoNaNsFPMath, HasMadd4] in {
   def NMADD_S : MMRel, NMADDS_FT<"nmadd.s", FGR32Opnd, II_NMADD_S, fadd>,
                 MADDS_FM<6, 0>, INSN_MIPS4_32R2_NOT_32R6_64R6;
   def NMSUB_S : MMRel, NMADDS_FT<"nmsub.s", FGR32Opnd, II_NMSUB_S, fsub>,
@@ -569,11 +569,11 @@ let AdditionalPredicates = [NoNaNsFPMath] in {
 }
 
 def MADD_D32 : MMRel, MADDS_FT<"madd.d", AFGR64Opnd, II_MADD_D, fadd>,
-               MADDS_FM<4, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_32;
+               MADDS_FM<4, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_32, MADD4;
 def MSUB_D32 : MMRel, MADDS_FT<"msub.d", AFGR64Opnd, II_MSUB_D, fsub>,
-               MADDS_FM<5, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_32;
+               MADDS_FM<5, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_32, MADD4;
 
-let AdditionalPredicates = [NoNaNsFPMath] in {
+let AdditionalPredicates = [NoNaNsFPMath, HasMadd4] in {
   def NMADD_D32 : MMRel, NMADDS_FT<"nmadd.d", AFGR64Opnd, II_NMADD_D, fadd>,
                   MADDS_FM<6, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_32;
   def NMSUB_D32 : MMRel, NMADDS_FT<"nmsub.d", AFGR64Opnd, II_NMSUB_D, fsub>,
@@ -582,12 +582,12 @@ let AdditionalPredicates = [NoNaNsFPMath] in {
 
 let DecoderNamespace = "Mips64" in {
   def MADD_D64 : MADDS_FT<"madd.d", FGR64Opnd, II_MADD_D, fadd>,
-                 MADDS_FM<4, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_64;
+                 MADDS_FM<4, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_64, MADD4;
   def MSUB_D64 : MADDS_FT<"msub.d", FGR64Opnd, II_MSUB_D, fsub>,
-                 MADDS_FM<5, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_64;
+                 MADDS_FM<5, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_64, MADD4;
 }
 
-let AdditionalPredicates = [NoNaNsFPMath],
+let AdditionalPredicates = [NoNaNsFPMath, HasMadd4],
     DecoderNamespace = "Mips64" in {
   def NMADD_D64 : NMADDS_FT<"nmadd.d", FGR64Opnd, II_NMADD_D, fadd>,
                   MADDS_FM<6, 1>, INSN_MIPS4_32R2_NOT_32R6_64R6, FGR_64;
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.td b/llvm/lib/Target/Mips/MipsInstrInfo.td
index 8761946b8db..40078fb7714 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.td
@@ -238,6 +238,8 @@ def HasEVA       :    Predicate<"Subtarget->hasEVA()">,
                       AssemblerPredicate<"FeatureEVA,FeatureMips32r2">;
 def HasMSA : Predicate<"Subtarget->hasMSA()">,
              AssemblerPredicate<"FeatureMSA">;
+def HasMadd4 : Predicate<"!Subtarget->disableMadd4()">,
+               AssemblerPredicate<"!FeatureMadd4">;
 
 
 //===----------------------------------------------------------------------===//
@@ -390,6 +392,10 @@ class ASE_NOT_DSP {
   list<Predicate> InsnPredicates = [NotDSP];
 }
 
+class MADD4 {
+  list<Predicate> AdditionalPredicates = [HasMadd4];
+}
+
 //===----------------------------------------------------------------------===//
 
 class MipsPat<dag pattern, dag result> : Pat<pattern, result>, PredicateControl {
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 6b4a3f9a140..154d5825427 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -70,7 +70,7 @@ MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
       InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
       HasDSPR2(false), HasDSPR3(false), AllowMixed16_32(Mixed16_32 | Mips_Os16),
       Os16(Mips_Os16), HasMSA(false), UseTCCInDIV(false), HasSym32(false),
-      HasEVA(false), TM(TM), TargetTriple(TT), TSInfo(),
+      HasEVA(false), DisableMadd4(false), TM(TM), TargetTriple(TT), TSInfo(),
       InstrInfo(
           MipsInstrInfo::create(initializeSubtargetDependencies(CPU, FS, TM))),
       FrameLowering(MipsFrameLowering::create(*this)),
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.h b/llvm/lib/Target/Mips/MipsSubtarget.h
index b4d15ee361f..ba9f9d2836a 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.h
+++ b/llvm/lib/Target/Mips/MipsSubtarget.h
@@ -144,6 +144,10 @@ class MipsSubtarget : public MipsGenSubtargetInfo {
 
   // HasEVA -- supports EVA ASE.
   bool HasEVA;
+  
+  // nomadd4 - disables generation of 4-operand madd.s, madd.d and
+  // related instructions.
+  bool DisableMadd4;
 
   InstrItineraryData InstrItins;
 
@@ -253,6 +257,7 @@ public:
   bool hasDSPR2() const { return HasDSPR2; }
   bool hasDSPR3() const { return HasDSPR3; }
   bool hasMSA() const { return HasMSA; }
+  bool disableMadd4() const { return DisableMadd4; }
   bool hasEVA() const { return HasEVA; }
   bool useSmallSection() const { return UseSmallSection; }