[llvm] [AArch64] Improve scalar fixed-point int-to-fp codegen (PR #220299)

[Vimal Patel via llvm-commits]

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@@ -9698,21 +9720,43 @@ defm : FPToFixedScalarPats<int_aarch64_neon_vcvtfp2fxu, "FCVTZU">;
 // Codegen patterns for SCVTF and UCVTF. We don't put these directly on the
 // instructions because TableGen's type inference can't handle the truth.
 // Having the same base pattern for fp <--> int totally freaks it out.
-def : Pat<(int_aarch64_neon_vcvtfxu2fp FPR32:$Rn, vecshiftR32:$imm),
+def : Pat<(int_aarch64_neon_vcvtfxu2fp (i32 (bitconvert (f32 FPR32:$Rn))), vecshiftR32:$imm),
           (UCVTFs FPR32:$Rn, vecshiftR32:$imm)>;
-def : Pat<(f64 (int_aarch64_neon_vcvtfxu2fp (i64 FPR64:$Rn), vecshiftR64:$imm)),
+def : Pat<(f64 (int_aarch64_neon_vcvtfxu2fp (i64 (bitconvert (f64 FPR64:$Rn))),
+                                            vecshiftR64:$imm)),
           (UCVTFd FPR64:$Rn, vecshiftR64:$imm)>;
 def : Pat<(v1f64 (int_aarch64_neon_vcvtfxs2fp (v1i64 FPR64:$Rn),
                                             vecshiftR64:$imm)),
           (SCVTFd FPR64:$Rn, vecshiftR64:$imm)>;
-def : Pat<(f64 (int_aarch64_neon_vcvtfxs2fp (i64 FPR64:$Rn), vecshiftR64:$imm)),
+def : Pat<(f64 (int_aarch64_neon_vcvtfxs2fp (i64 (bitconvert (f64 FPR64:$Rn))),
+                                            vecshiftR64:$imm)),
           (SCVTFd FPR64:$Rn, vecshiftR64:$imm)>;
 def : Pat<(v1f64 (int_aarch64_neon_vcvtfxu2fp (v1i64 FPR64:$Rn),
                                             vecshiftR64:$imm)),
           (UCVTFd FPR64:$Rn, vecshiftR64:$imm)>;
-def : Pat<(int_aarch64_neon_vcvtfxs2fp FPR32:$Rn, vecshiftR32:$imm),
+def : Pat<(int_aarch64_neon_vcvtfxs2fp (i32 (bitconvert (f32 FPR32:$Rn))), vecshiftR32:$imm),
           (SCVTFs FPR32:$Rn, vecshiftR32:$imm)>;
 
+multiclass FixedPointUToFPFromV128ExtractPat<ValueType VecTy> {
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pvimal816a wrote:

If this is a legacy intrinsic then I'll just update the umaxv's lowering and not touch any related instructions like uminv. This is to avoid updating the regressing test case and to preserve the existing behaviour.

https://github.com/llvm/llvm-project/pull/220299