[llvm] [AMDGPU] Use SDNodeXForm to select a few VOP3P modifiers, NFC (PR #151907)

[Changpeng Fang via llvm-commits]

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@@ -7102,6 +7042,38 @@ void AMDGPUInstructionSelector::renderRoundMode(MachineInstrBuilder &MIB,
   MIB.addImm((MI.getOperand(OpIdx).getImm() + 3) % 4);
 }
 
+void AMDGPUInstructionSelector::renderVOP3PModsNeg(MachineInstrBuilder &MIB,
+                                                   const MachineInstr &MI,
+                                                   int OpIdx) const {
+  unsigned Mods = SISrcMods::OP_SEL_1;
+  if (MI.getOperand(OpIdx).getImm())
+    Mods ^= SISrcMods::NEG;
+  MIB.addImm((int64_t)Mods);
+}
+
+void AMDGPUInstructionSelector::renderVOP3PModsNegs(MachineInstrBuilder &MIB,
+                                                    const MachineInstr &MI,
+                                                    int OpIdx) const {
+  unsigned Mods = SISrcMods::OP_SEL_1;
+  if (MI.getOperand(OpIdx).getImm())
+    Mods ^= (SISrcMods::NEG | SISrcMods::NEG_HI);
+  MIB.addImm((int64_t)Mods);
+}
+
+void AMDGPUInstructionSelector::renderVOP3PModsNegAbs(MachineInstrBuilder &MIB,
+                                                      const MachineInstr &MI,
+                                                      int OpIdx) const {
+  unsigned Val = MI.getOperand(OpIdx).getImm();
+  unsigned Mods = SISrcMods::OP_SEL_1;
+  if (Val == 1)
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changpeng wrote:

> Magic numbers, these are presumably some enum?

Yes, SISrcMods::OP_SEL_1 is an enum number, and is widely used in the tablegen at AMDGPU backend.

https://github.com/llvm/llvm-project/pull/151907