[RISCV] Add immop_oneuse PatLeaf. Use it to replace some PatLeafs with ImmLeaf/IntImmLeaf. NFC

If we needed a one use check of a constant, we used a PatLeaf instead of
an IntLeaf or IntImmLeaf so we could add the one use check. Unfortunately,
this required the custom code to be duplicated for GISel too.

Instead we can use a PatLeaf that does the one use check and defers
to an IntLeaf or IntImmLeaf for the immediate check. This allows
GISel to automically import the IntLeaf/IntImmLeaf part and we only
need the custom GISel predicate in the immop_oneuse PatLeaf.

Author: topperc

llvm/lib/Target/RISCV/RISCVInstrInfo.td

@@ -448,20 +448,10 @@ def GIImmSubFrom32 : GICustomOperandRenderer<"renderImmSubFrom32">,
 // in which imm = imm0 + imm1 and both imm0 and imm1 are simm12. We make imm0
 // as large as possible and imm1 as small as possible so that we might be able
 // to use c.addi for the small immediate.
-def AddiPair : PatLeaf<(imm), [{
-  if (!N->hasOneUse())
-    return false;
+def AddiPair : ImmLeaf<XLenVT, [{
   // The immediate operand must be in range [-4096,-2049] or [2048,4094].
-  int64_t Imm = N->getSExtValue();
   return (-4096 <= Imm && Imm <= -2049) || (2048 <= Imm && Imm <= 4094);
-}]> {
-  let GISelPredicateCode = [{
-    if (!MRI.hasOneNonDBGUse(MI.getOperand(0).getReg()))
-      return false;
-    int64_t Imm = MI.getOperand(1).getCImm()->getSExtValue();
-    return (-4096 <= Imm && Imm <= -2049) || (2048 <= Imm && Imm <= 4094);
-  }];
-}
+}]>;
 
 // Return imm - (imm < 0 ? -2048 : 2047).
 def AddiPairImmSmall : SDNodeXForm<imm, [{
@@ -500,55 +490,23 @@ def GIXLenSubTrailingOnes : GICustomOperandRenderer<"renderXLenSubTrailingOnes">
 
 // Checks if this mask is a non-empty sequence of ones starting at the
 // most/least significant bit with the remainder zero and exceeds simm32/simm12.
-def LeadingOnesMask : PatLeaf<(imm), [{
-  if (!N->hasOneUse())
-    return false;
-  return !isInt<32>(N->getSExtValue()) && isMask_64(~N->getSExtValue());
-}], TrailingZeros> {
-  let GISelPredicateCode = [{
-    if (!MRI.hasOneNonDBGUse(MI.getOperand(0).getReg()))
-      return false;
-    const auto &MO = MI.getOperand(1);
-    return !isInt<32>(MO.getCImm()->getSExtValue()) && 
-           isMask_64(~MO.getCImm()->getSExtValue());
-  }];
-}
+def LeadingOnesMask : ImmLeaf<XLenVT, [{
+  return !isInt<32>(Imm) && isMask_64(~Imm);
+}], TrailingZeros>;
 
-def TrailingOnesMask : PatLeaf<(imm), [{
-  if (!N->hasOneUse())
-    return false;
-  return !isInt<12>(N->getSExtValue()) && isMask_64(N->getZExtValue());
-}], XLenSubTrailingOnes> {
-  let GISelPredicateCode = [{
-    if (!MRI.hasOneNonDBGUse(MI.getOperand(0).getReg()))
-      return false;
-    const auto &MO = MI.getOperand(1);
-    return !isInt<12>(MO.getCImm()->getSExtValue()) &&
-           isMask_64(MO.getCImm()->getZExtValue());
-  }];
-}
+def TrailingOnesMask : IntImmLeaf<XLenVT, [{
+  return !isInt<12>(Imm.getSExtValue()) && isMask_64(Imm.getZExtValue());
+}], XLenSubTrailingOnes>;
 
 // Similar to LeadingOnesMask, but only consider leading ones in the lower 32
 // bits.
-def LeadingOnesWMask : PatLeaf<(imm), [{
-  if (!N->hasOneUse())
-    return false;
+def LeadingOnesWMask : ImmLeaf<XLenVT, [{
   // If the value is a uint32 but not an int32, it must have bit 31 set and
   // bits 63:32 cleared. After that we're looking for a shifted mask but not
   // an all ones mask.
-  int64_t Imm = N->getSExtValue();
   return !isInt<32>(Imm) && isUInt<32>(Imm) && isShiftedMask_64(Imm) &&
          Imm != UINT64_C(0xffffffff);
-}], TrailingZeros> {
-  let GISelPredicateCode = [{
-    if (!MRI.hasOneNonDBGUse(MI.getOperand(0).getReg()))
-      return false;
-    const auto &MO = MI.getOperand(1);
-    int64_t Imm = MO.getCImm()->getSExtValue();
-    return !isInt<32>(Imm) && isUInt<32>(Imm) && isShiftedMask_64(Imm) &&
-           Imm != UINT64_C(0xffffffff);
-  }];
-}
+}], TrailingZeros>;
 
 //===----------------------------------------------------------------------===//
 // Instruction Formats
@@ -1358,6 +1316,14 @@ def 33signbits_node : PatLeaf<(i64 GPR:$src), [{
   return CurDAG->ComputeNumSignBits(SDValue(N, 0)) > 32;
 }]>;
 
+class immop_oneuse<ImmLeaf leaf> : PatLeaf<(leaf), [{
+  return N->hasOneUse();
+}]> {
+  let GISelPredicateCode = [{
+    return MRI.hasOneNonDBGUse(MI.getOperand(0).getReg());
+  }];
+}
+
 /// Simple arithmetic operations
 
 def : PatGprGpr<add, ADD>;
@@ -1395,10 +1361,12 @@ def : Pat<(XLenVT (sub 0, (and_oneuse GPR:$rs, 1))),
                 (ImmSubFromXLen (XLenVT 1)))>;
 
 // AND with leading/trailing ones mask exceeding simm32/simm12.
-def : Pat<(i64 (and GPR:$rs, LeadingOnesMask:$mask)),
-          (SLLI (i64 (SRLI $rs, LeadingOnesMask:$mask)), LeadingOnesMask:$mask)>;
-def : Pat<(XLenVT (and GPR:$rs, TrailingOnesMask:$mask)),
-          (SRLI (XLenVT (SLLI $rs, TrailingOnesMask:$mask)), TrailingOnesMask:$mask)>;
+def : Pat<(i64 (and GPR:$rs, immop_oneuse<LeadingOnesMask>:$mask)),
+          (SLLI (i64 (SRLI $rs, (TrailingZeros imm:$mask))),
+                (TrailingZeros imm:$mask))>;
+def : Pat<(XLenVT (and GPR:$rs, immop_oneuse<TrailingOnesMask>:$mask)),
+          (SRLI (XLenVT (SLLI $rs, (XLenSubTrailingOnes imm:$mask))),
+                (XLenSubTrailingOnes imm:$mask))>;
 
 // Match both a plain shift and one where the shift amount is masked (this is
 // typically introduced when the legalizer promotes the shift amount and
@@ -1989,8 +1957,9 @@ def u32simm12 : ImmLeaf<XLenVT, [{
 
 let Predicates = [IsRV64] in {
 
-def : Pat<(i64 (and GPR:$rs, LeadingOnesWMask:$mask)),
-          (SLLI (i64 (SRLIW $rs, LeadingOnesWMask:$mask)), LeadingOnesWMask:$mask)>;
+def : Pat<(i64 (and GPR:$rs, immop_oneuse<LeadingOnesWMask>:$mask)),
+          (SLLI (i64 (SRLIW $rs, (TrailingZeros imm:$mask))),
+                (TrailingZeros imm:$mask))>;
 
 /// sext and zext
 
@@ -2089,15 +2058,15 @@ def KCFI_CHECK
 }
 
 /// Simple optimization
-def : Pat<(XLenVT (add GPR:$rs1, (AddiPair:$rs2))),
-          (ADDI (XLenVT (ADDI GPR:$rs1, (AddiPairImmLarge AddiPair:$rs2))),
-                (AddiPairImmSmall GPR:$rs2))>;
+def : Pat<(XLenVT (add GPR:$rs1, immop_oneuse<AddiPair>:$rs2)),
+          (ADDI (XLenVT (ADDI GPR:$rs1, (AddiPairImmLarge imm:$rs2))),
+                (AddiPairImmSmall imm:$rs2))>;
 
 let Predicates = [IsRV64] in {
 // Select W instructions if only the lower 32-bits of the result are used.
-def : Pat<(binop_allwusers<add> GPR:$rs1, (AddiPair:$rs2)),
-          (ADDIW (i64 (ADDIW GPR:$rs1, (AddiPairImmLarge AddiPair:$rs2))),
-                 (AddiPairImmSmall AddiPair:$rs2))>;
+def : Pat<(binop_allwusers<add> GPR:$rs1, immop_oneuse<AddiPair>:$rs2),
+          (ADDIW (i64 (ADDIW GPR:$rs1, (AddiPairImmLarge imm:$rs2))),
+                 (AddiPairImmSmall imm:$rs2))>;
 }
 
 //===----------------------------------------------------------------------===//