[AArch64][SME2] Add builtins to cast svbool from/to svcount. (#74720)

Add builtin: 'svreinterpret_b' to cast from svcount_t to svbool_t.
Add builtin: 'svreinterpret_c'  to cast from svbool_t  to svcount_t.

Patch by: Hassnaa Hamdi <hassnaa.hamdi@arm.com>

clang/include/clang/Basic/arm_sve.td

@@ -2161,6 +2161,9 @@ let TargetGuard = "sme2" in {
   def SVSQRSHRU_X4 : SInst<"svqrshru[_n]_{0}[_{d}_x4]", "b4i", "il", MergeNone, "aarch64_sve_sqrshru_x4", [IsStreaming], [ImmCheck<1, ImmCheckShiftRight, 0>]>;
 
   def SVSQRSHRUN_X4 : SInst<"svqrshrun[_n]_{0}[_{d}_x4]", "b4i", "il", MergeNone, "aarch64_sve_sqrshrun_x4", [IsStreaming], [ImmCheck<1, ImmCheckShiftRight, 0>]>;
+
+  def REINTERPRET_SVBOOL_TO_SVCOUNT : Inst<"svreinterpret[_c]", "}P", "Pc", MergeNone, "", [IsStreamingCompatible], []>;
+  def REINTERPRET_SVCOUNT_TO_SVBOOL : Inst<"svreinterpret[_b]", "P}", "Pc", MergeNone, "", [IsStreamingCompatible], []>;
 }
 
 let TargetGuard = "sve2p1" in {

clang/lib/CodeGen/CGBuiltin.cpp

@@ -10211,6 +10211,22 @@ Value *CodeGenFunction::EmitAArch64SVEBuiltinExpr(unsigned BuiltinID,
   switch (BuiltinID) {
   default:
     return nullptr;
+
+  case SVE::BI__builtin_sve_svreinterpret_b: {
+    auto SVCountTy =
+        llvm::TargetExtType::get(getLLVMContext(), "aarch64.svcount");
+    Function *CastFromSVCountF =
+        CGM.getIntrinsic(Intrinsic::aarch64_sve_convert_to_svbool, SVCountTy);
+    return Builder.CreateCall(CastFromSVCountF, Ops[0]);
+  }
+  case SVE::BI__builtin_sve_svreinterpret_c: {
+    auto SVCountTy =
+        llvm::TargetExtType::get(getLLVMContext(), "aarch64.svcount");
+    Function *CastToSVCountF =
+        CGM.getIntrinsic(Intrinsic::aarch64_sve_convert_from_svbool, SVCountTy);
+    return Builder.CreateCall(CastToSVCountF, Ops[0]);
+  }
+
   case SVE::BI__builtin_sve_svpsel_lane_b8:
   case SVE::BI__builtin_sve_svpsel_lane_b16:
   case SVE::BI__builtin_sve_svpsel_lane_b32:

clang/test/CodeGen/aarch64-sme2-intrinsics/acle_sme2_reinterpret_svcount_svbool.c

@@ -0,0 +1,47 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+
+// REQUIRES: aarch64-registered-target
+
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +sme2 -S -disable-O0-optnone -Werror -Wall -emit-llvm -o - %s | opt -S -p mem2reg,instcombine,tailcallelim | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +sme2 -S -disable-O0-optnone -Werror -Wall -emit-llvm -o - -x c++ %s | opt -S -p mem2reg,instcombine,tailcallelim | FileCheck %s -check-prefix=CPP-CHECK
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +sme2 -S -disable-O0-optnone -Werror -Wall -emit-llvm -o - %s | opt -S -p mem2reg,instcombine,tailcallelim | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +sme2 -S -disable-O0-optnone -Werror -Wall -emit-llvm -o - -x c++ %s | opt -S -p mem2reg,instcombine,tailcallelim | FileCheck %s -check-prefix=CPP-CHECK
+
+#include <arm_sme_draft_spec_subject_to_change.h>
+
+#ifdef SVE_OVERLOADED_FORMS
+// A simple used,unused... macro, long enough to represent any SVE builtin.§
+#define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
+#else
+#define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4
+#endif
+
+// CHECK-LABEL: @test_svreinterpret_svbool_svcnt(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = tail call <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool.taarch64.svcountt(target("aarch64.svcount") [[CNT:%.*]])
+// CHECK-NEXT:    ret <vscale x 16 x i1> [[TMP0]]
+//
+// CPP-CHECK-LABEL: @_Z31test_svreinterpret_svbool_svcntu11__SVCount_t(
+// CPP-CHECK-NEXT:  entry:
+// CPP-CHECK-NEXT:    [[TMP0:%.*]] = tail call <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool.taarch64.svcountt(target("aarch64.svcount") [[CNT:%.*]])
+// CPP-CHECK-NEXT:    ret <vscale x 16 x i1> [[TMP0]]
+//
+svbool_t test_svreinterpret_svbool_svcnt(svcount_t cnt) __arm_streaming_compatible
+{
+  return SVE_ACLE_FUNC(svreinterpret,_b,,)(cnt);
+}
+
+// CHECK-LABEL: @test_svreinterpret_svcnt_svbool(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = tail call target("aarch64.svcount") @llvm.aarch64.sve.convert.from.svbool.taarch64.svcountt(<vscale x 16 x i1> [[PG:%.*]])
+// CHECK-NEXT:    ret target("aarch64.svcount") [[TMP0]]
+//
+// CPP-CHECK-LABEL: @_Z31test_svreinterpret_svcnt_svboolu10__SVBool_t(
+// CPP-CHECK-NEXT:  entry:
+// CPP-CHECK-NEXT:    [[TMP0:%.*]] = tail call target("aarch64.svcount") @llvm.aarch64.sve.convert.from.svbool.taarch64.svcountt(<vscale x 16 x i1> [[PG:%.*]])
+// CPP-CHECK-NEXT:    ret target("aarch64.svcount") [[TMP0]]
+//
+svcount_t test_svreinterpret_svcnt_svbool(svbool_t pg) __arm_streaming_compatible
+{
+  return SVE_ACLE_FUNC(svreinterpret,_c,,)(pg);
+}