2 files changed, 18 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86LegalizerInfo.cpp b/llvm/lib/Target/X86/X86LegalizerInfo.cpp
index b8c31ddc004..d372cada8de 100644
--- a/llvm/lib/Target/X86/X86LegalizerInfo.cpp
+++ b/llvm/lib/Target/X86/X86LegalizerInfo.cpp
@@ -212,6 +212,13 @@ void X86LegalizerInfo::setLegalizerInfo64bit() {
     setAction({extOp, s64}, Legal);
   }
 
+  getActionDefinitionsBuilder(G_SITOFP)
+    .legalForCartesianProduct({s32, s64})
+      .clampScalar(1, s32, s64)
+      .widenScalarToNextPow2(1)
+      .clampScalar(0, s32, s64)
+      .widenScalarToNextPow2(0);
+
   // Comparison
   setAction({G_ICMP, 1, s64}, Legal);
 
diff --git a/llvm/lib/Target/X86/X86RegisterBankInfo.cpp b/llvm/lib/Target/X86/X86RegisterBankInfo.cpp
index 85d230e4b20..246d6d5a58d 100644
--- a/llvm/lib/Target/X86/X86RegisterBankInfo.cpp
+++ b/llvm/lib/Target/X86/X86RegisterBankInfo.cpp
@@ -198,6 +198,17 @@ X86RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
     // Instruction having only floating-point operands (all scalars in VECRReg)
     getInstrPartialMappingIdxs(MI, MRI, /* isFP */ true, OpRegBankIdx);
     break;
+  case TargetOpcode::G_SITOFP: {
+    // Some of the floating-point instructions have mixed GPR and FP operands:
+    // fine-tune the computed mapping.
+    auto &Op0 = MI.getOperand(0);
+    auto &Op1 = MI.getOperand(1);
+    const LLT Ty0 = MRI.getType(Op0.getReg());
+    const LLT Ty1 = MRI.getType(Op1.getReg());
+    OpRegBankIdx[0] = getPartialMappingIdx(Ty0, /* isFP */ true);
+    OpRegBankIdx[1] = getPartialMappingIdx(Ty1, /* isFP */ false);
+    break;
+  }
   case TargetOpcode::G_TRUNC:
   case TargetOpcode::G_ANYEXT: {
     auto &Op0 = MI.getOperand(0);