[llvm] [X86][GlobalIsel] support G_FABS (PR #136718)

[Simon Pilgrim via llvm-commits]

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@@ -835,6 +841,43 @@ bool X86LegalizerInfo::legalizeNarrowingStore(MachineInstr &MI,
   return true;
 }
 
+bool X86LegalizerInfo::legalizeFAbs(MachineInstr &MI,
+                                         MachineRegisterInfo &MRI,
+                                         LegalizerHelper &Helper) const {
+
+  MachineIRBuilder &MIRBuilder = Helper.MIRBuilder;
+  Register SrcReg = MI.getOperand(1).getReg();
+  Register DstReg = MI.getOperand(0).getReg();
+  LLT Ty = MRI.getType(DstReg);
+  if (Subtarget.is32Bit()) {
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RKSimon wrote:

why not support f64 on Subtarget.is64Bit()?

https://github.com/llvm/llvm-project/pull/136718