[llvm] [AArch64][GlobalISel] Add codegen for simd fpcvt instructions (PR #156892)

[via llvm-commits]

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@@ -5212,18 +5212,55 @@ defm FCVTZU : FPToIntegerUnscaled<0b11, 0b001, "fcvtzu", any_fp_to_uint>;
 defm FCVTZS : FPToIntegerScaled<0b11, 0b000, "fcvtzs", any_fp_to_sint>;
 defm FCVTZU : FPToIntegerScaled<0b11, 0b001, "fcvtzu", any_fp_to_uint>;
 
+defm FCVTAS : SIMDFPTwoScalarFCVT<   0, 0, 0b11100, "fcvtas", int_aarch64_neon_fcvtas>;
+defm FCVTAU : SIMDFPTwoScalarFCVT<   1, 0, 0b11100, "fcvtau", int_aarch64_neon_fcvtau>;
+defm FCVTMS : SIMDFPTwoScalarFCVT<   0, 0, 0b11011, "fcvtms", int_aarch64_neon_fcvtms>;
+defm FCVTMU : SIMDFPTwoScalarFCVT<   1, 0, 0b11011, "fcvtmu", int_aarch64_neon_fcvtmu>;
+defm FCVTNS : SIMDFPTwoScalarFCVT<   0, 0, 0b11010, "fcvtns", int_aarch64_neon_fcvtns>;
+defm FCVTNU : SIMDFPTwoScalarFCVT<   1, 0, 0b11010, "fcvtnu", int_aarch64_neon_fcvtnu>;
+defm FCVTPS : SIMDFPTwoScalarFCVT<   0, 1, 0b11010, "fcvtps", int_aarch64_neon_fcvtps>;
+defm FCVTPU : SIMDFPTwoScalarFCVT<   1, 1, 0b11010, "fcvtpu", int_aarch64_neon_fcvtpu>;
+defm FCVTZS : SIMDFPTwoScalarFCVT<   0, 1, 0b11011, "fcvtzs", any_fp_to_sint>;
+defm FCVTZU : SIMDFPTwoScalarFCVT<   1, 1, 0b11011, "fcvtzu", any_fp_to_uint>;
+
 let Predicates = [HasNEON, HasFPRCVT] in{
-  defm FCVTAS : FPToIntegerSIMDScalar<0b11, 0b010, "fcvtas">;
-  defm FCVTAU : FPToIntegerSIMDScalar<0b11, 0b011, "fcvtau">;
-  defm FCVTMS : FPToIntegerSIMDScalar<0b10, 0b100, "fcvtms">;
-  defm FCVTMU : FPToIntegerSIMDScalar<0b10, 0b101, "fcvtmu">;
-  defm FCVTNS : FPToIntegerSIMDScalar<0b01, 0b010, "fcvtns">;
-  defm FCVTNU : FPToIntegerSIMDScalar<0b01, 0b011, "fcvtnu">;
-  defm FCVTPS : FPToIntegerSIMDScalar<0b10, 0b010, "fcvtps">;
-  defm FCVTPU : FPToIntegerSIMDScalar<0b10, 0b011, "fcvtpu">;
-  defm FCVTZS : FPToIntegerSIMDScalar<0b10, 0b110, "fcvtzs">;
-  defm FCVTZU : FPToIntegerSIMDScalar<0b10, 0b111, "fcvtzu">;
-}
+  defm FCVTAS : FPToIntegerSIMDScalar<0b11, 0b010, "fcvtas", int_aarch64_neon_fcvtas>;
+  defm FCVTAU : FPToIntegerSIMDScalar<0b11, 0b011, "fcvtau", int_aarch64_neon_fcvtau>;
+  defm FCVTMS : FPToIntegerSIMDScalar<0b10, 0b100, "fcvtms", int_aarch64_neon_fcvtms>;
+  defm FCVTMU : FPToIntegerSIMDScalar<0b10, 0b101, "fcvtmu", int_aarch64_neon_fcvtmu>;
+  defm FCVTNS : FPToIntegerSIMDScalar<0b01, 0b010, "fcvtns", int_aarch64_neon_fcvtns>;
+  defm FCVTNU : FPToIntegerSIMDScalar<0b01, 0b011, "fcvtnu", int_aarch64_neon_fcvtnu>;
+  defm FCVTPS : FPToIntegerSIMDScalar<0b10, 0b010, "fcvtps", int_aarch64_neon_fcvtps>;
+  defm FCVTPU : FPToIntegerSIMDScalar<0b10, 0b011, "fcvtpu", int_aarch64_neon_fcvtpu>;
+  defm FCVTZS : FPToIntegerSIMDScalar<0b10, 0b110, "fcvtzs", any_fp_to_sint>;
+  defm FCVTZU : FPToIntegerSIMDScalar<0b10, 0b111, "fcvtzu", any_fp_to_uint>;
+}
+
+multiclass FPToIntegerSIMDScalarPatterns<SDPatternOperator OpN, string INST> {
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Lukacma wrote:

I don't think there is any work necessary for clang, unless we try to change lowering of NEON scalar integer intrinsics to use single elements vector, in which case this whole patch will be irrelevant. The bitconvert will not get removed, because it is only going to be added during(after?) code legalization and there are, as far as I know,  no optimizations which would remove  before instruction selection

https://github.com/llvm/llvm-project/pull/156892