[AArch64][ARM] Avoid some APFloat copies in tablegen patterns. NFC. (#114416)

Either the N->getValueAPF() was being unused or we were failing to make use of it returning a const APFloat&

Author: RKSimon

llvm/lib/Target/AArch64/AArch64InstrFormats.td

@@ -1390,15 +1390,13 @@ def arith_uxtx : ComplexPattern<i64, 2, "SelectArithUXTXRegister", []>;
 // Floating-point immediate.
 
 def fpimm16XForm : SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = AArch64_AM::getFP16Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = AArch64_AM::getFP16Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>;
 
 def fpimm32XForm : SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = AArch64_AM::getFP32Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = AArch64_AM::getFP32Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>;
 
 def fpimm32SIMDModImmType4XForm : SDNodeXForm<fpimm, [{
@@ -1409,9 +1407,8 @@ def fpimm32SIMDModImmType4XForm : SDNodeXForm<fpimm, [{
     }]>;
 
 def fpimm64XForm : SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = AArch64_AM::getFP64Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = AArch64_AM::getFP64Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>;
 
 def fpimm16 : Operand<f16>,
@@ -1681,7 +1678,6 @@ def simdimmtype10 : Operand<i32>,
       return AArch64_AM::isAdvSIMDModImmType10(
                  Imm.bitcastToAPInt().getZExtValue());
     }], SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
       uint32_t enc = AArch64_AM::encodeAdvSIMDModImmType10(N->getValueAPF()
                                                            .bitcastToAPInt()
                                                            .getZExtValue());

llvm/lib/Target/ARM/ARMInstrVFP.td

@@ -46,28 +46,25 @@ def vfp_f16imm : Operand<f16>,
                  PatLeaf<(f16 fpimm), [{
       return ARM_AM::getFP16Imm(N->getValueAPF()) != -1;
     }], SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = ARM_AM::getFP16Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = ARM_AM::getFP16Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>> {
   let PrintMethod = "printFPImmOperand";
   let ParserMatchClass = FPImmOperand;
 }
 
 def vfp_f32f16imm_xform : SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = ARM_AM::getFP32FP16Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = ARM_AM::getFP32FP16Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>;
 
 def vfp_f32f16imm : PatLeaf<(f32 fpimm), [{
       return ARM_AM::getFP32FP16Imm(N->getValueAPF()) != -1;
     }], vfp_f32f16imm_xform>;
 
 def vfp_f32imm_xform : SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = ARM_AM::getFP32Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = ARM_AM::getFP32Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>;
 
 def gi_vfp_f32imm : GICustomOperandRenderer<"renderVFPF32Imm">,
@@ -88,9 +85,8 @@ def vfp_f32imm : Operand<f32>,
 }
 
 def vfp_f64imm_xform : SDNodeXForm<fpimm, [{
-      APFloat InVal = N->getValueAPF();
-      uint32_t enc = ARM_AM::getFP64Imm(InVal);
-      return CurDAG->getTargetConstant(enc, SDLoc(N), MVT::i32);
+      uint32_t Enc = ARM_AM::getFP64Imm(N->getValueAPF());
+      return CurDAG->getTargetConstant(Enc, SDLoc(N), MVT::i32);
     }]>;
 
 def gi_vfp_f64imm : GICustomOperandRenderer<"renderVFPF64Imm">,