[NVPTX] Removed always-true predicates in NVPTX.

NVPTX stopped supporting GPUs older than sm_20 (Fermi) quite a while back.
Removal of support of pre-Fermi GPUs made a lot of predicates in the NVPTX
backend pointless as they can't ever be false any more.
It's time to retire them. NFC intended.

Differential Revision: https://reviews.llvm.org/D43843

llvm-svn: 326349

Author: Artem-B

llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp

@@ -974,10 +974,6 @@ void NVPTXAsmPrinter::emitHeader(Module &M, raw_ostream &O,
   const NVPTXTargetMachine &NTM = static_cast<const NVPTXTargetMachine &>(TM);
   if (NTM.getDrvInterface() == NVPTX::NVCL)
     O << ", texmode_independent";
-  else {
-    if (!STI.hasDouble())
-      O << ", map_f64_to_f32";
-  }
 
   if (MAI->doesSupportDebugInformation())
     O << ", debug";

llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp

@@ -417,20 +417,13 @@ NVPTXTargetLowering::NVPTXTargetLowering(const NVPTXTargetMachine &TM,
   setOperationAction(ISD::BITREVERSE, MVT::i32, Legal);
   setOperationAction(ISD::BITREVERSE, MVT::i64, Legal);
 
-  if (STI.hasROT64()) {
-    setOperationAction(ISD::ROTL, MVT::i64, Legal);
-    setOperationAction(ISD::ROTR, MVT::i64, Legal);
-  } else {
-    setOperationAction(ISD::ROTL, MVT::i64, Expand);
-    setOperationAction(ISD::ROTR, MVT::i64, Expand);
-  }
-  if (STI.hasROT32()) {
-    setOperationAction(ISD::ROTL, MVT::i32, Legal);
-    setOperationAction(ISD::ROTR, MVT::i32, Legal);
-  } else {
-    setOperationAction(ISD::ROTL, MVT::i32, Expand);
-    setOperationAction(ISD::ROTR, MVT::i32, Expand);
-  }
+  // TODO: we may consider expanding ROTL/ROTR on older GPUs.  Currently on GPUs
+  // that don't have h/w rotation we lower them to multi-instruction assembly.
+  // See ROT*_sw in NVPTXIntrInfo.td
+  setOperationAction(ISD::ROTL, MVT::i64, Legal);
+  setOperationAction(ISD::ROTR, MVT::i64, Legal);
+  setOperationAction(ISD::ROTL, MVT::i32, Legal);
+  setOperationAction(ISD::ROTR, MVT::i32, Legal);
 
   setOperationAction(ISD::ROTL, MVT::i16, Expand);
   setOperationAction(ISD::ROTR, MVT::i16, Expand);

llvm/lib/Target/NVPTX/NVPTXInstrInfo.td

@@ -111,28 +111,14 @@ def VecElement : Operand<i32> {
 //===----------------------------------------------------------------------===//
 
 
-def hasAtomRedG32 : Predicate<"Subtarget->hasAtomRedG32()">;
-def hasAtomRedS32 : Predicate<"Subtarget->hasAtomRedS32()">;
-def hasAtomRedGen32 : Predicate<"Subtarget->hasAtomRedGen32()">;
-def useAtomRedG32forGen32 :
-  Predicate<"!Subtarget->hasAtomRedGen32() && Subtarget->hasAtomRedG32()">;
-def hasBrkPt : Predicate<"Subtarget->hasBrkPt()">;
-def hasAtomRedG64 : Predicate<"Subtarget->hasAtomRedG64()">;
-def hasAtomRedS64 : Predicate<"Subtarget->hasAtomRedS64()">;
-def hasAtomRedGen64 : Predicate<"Subtarget->hasAtomRedGen64()">;
-def useAtomRedG64forGen64 :
-  Predicate<"!Subtarget->hasAtomRedGen64() && Subtarget->hasAtomRedG64()">;
-def hasAtomAddF32 : Predicate<"Subtarget->hasAtomAddF32()">;
 def hasAtomAddF64 : Predicate<"Subtarget->hasAtomAddF64()">;
 def hasAtomScope : Predicate<"Subtarget->hasAtomScope()">;
 def hasAtomBitwise64 : Predicate<"Subtarget->hasAtomBitwise64()">;
 def hasAtomMinMax64 : Predicate<"Subtarget->hasAtomMinMax64()">;
 def hasVote : Predicate<"Subtarget->hasVote()">;
 def hasDouble : Predicate<"Subtarget->hasDouble()">;
-def reqPTX20 : Predicate<"Subtarget->reqPTX20()">;
 def hasLDG : Predicate<"Subtarget->hasLDG()">;
 def hasLDU : Predicate<"Subtarget->hasLDU()">;
-def hasGenericLdSt : Predicate<"Subtarget->hasGenericLdSt()">;
 
 def doF32FTZ : Predicate<"useF32FTZ()">;
 def doNoF32FTZ : Predicate<"!useF32FTZ()">;
@@ -961,13 +947,12 @@ def FDIV321r_prec_ftz :
             (ins f32imm:$a, Float32Regs:$b),
             "rcp.rn.ftz.f32 \t$dst, $b;",
             [(set Float32Regs:$dst, (fdiv FloatConst1:$a, Float32Regs:$b))]>,
-            Requires<[reqPTX20, doF32FTZ]>;
+            Requires<[doF32FTZ]>;
 def FDIV321r_prec :
   NVPTXInst<(outs Float32Regs:$dst),
             (ins f32imm:$a, Float32Regs:$b),
             "rcp.rn.f32 \t$dst, $b;",
-            [(set Float32Regs:$dst, (fdiv FloatConst1:$a, Float32Regs:$b))]>,
-            Requires<[reqPTX20]>;
+            [(set Float32Regs:$dst, (fdiv FloatConst1:$a, Float32Regs:$b))]>;
 //
 // F32 Accurate division
 //
@@ -976,25 +961,23 @@ def FDIV32rr_prec_ftz :
             (ins Float32Regs:$a, Float32Regs:$b),
             "div.rn.ftz.f32 \t$dst, $a, $b;",
             [(set Float32Regs:$dst, (fdiv Float32Regs:$a, Float32Regs:$b))]>,
-            Requires<[doF32FTZ, reqPTX20]>;
+            Requires<[doF32FTZ]>;
 def FDIV32ri_prec_ftz :
   NVPTXInst<(outs Float32Regs:$dst),
             (ins Float32Regs:$a, f32imm:$b),
             "div.rn.ftz.f32 \t$dst, $a, $b;",
             [(set Float32Regs:$dst, (fdiv Float32Regs:$a, fpimm:$b))]>,
-            Requires<[doF32FTZ, reqPTX20]>;
+            Requires<[doF32FTZ]>;
 def FDIV32rr_prec :
   NVPTXInst<(outs Float32Regs:$dst),
             (ins Float32Regs:$a, Float32Regs:$b),
             "div.rn.f32 \t$dst, $a, $b;",
-            [(set Float32Regs:$dst, (fdiv Float32Regs:$a, Float32Regs:$b))]>,
-            Requires<[reqPTX20]>;
+            [(set Float32Regs:$dst, (fdiv Float32Regs:$a, Float32Regs:$b))]>;
 def FDIV32ri_prec :
   NVPTXInst<(outs Float32Regs:$dst),
             (ins Float32Regs:$a, f32imm:$b),
             "div.rn.f32 \t$dst, $a, $b;",
-            [(set Float32Regs:$dst, (fdiv Float32Regs:$a, fpimm:$b))]>,
-            Requires<[reqPTX20]>;
+            [(set Float32Regs:$dst, (fdiv Float32Regs:$a, fpimm:$b))]>;
 
 //
 // FMA