[AArch64][SVE] Guard svbfloat16_t with feature macro in ACLE

[c-rhodes]

Summary

svbfloat16_t should only be defined if the __ARM_FEATURE_SVE_BF16
feature macro is enabled, similar to the scalar bfloat16_t type. Patch
also contains a fix for ld1ro intrinsic which should be guarded on
__ARM_FEATURE_SVE_BF16 rather than __ARM_FEATURE_BF16_SCALAR_ARITHMETIC.

[sdesmalen]

clang/utils/TableGen/SveEmitter.cpp

1094

Can you also add an error if __ARM_FEATURE_SVE_BF16 is defined, but __ARM_FEATURE_BF16_SCALAR_ARITHMETIC isn't?
something like:

#ifndef __ARM_FEATURE_BF16_SCALAR_ARITHMETIC
#error "__ARM_FEATURE_BF16_SCALAR_ARITHMETIC must be defined when __ARM_FEATURE_SVE_BF16 is defined"
#endif

[c-rhodes]

Changes:

• Error if __ARM_FEATURE_BF16_SCALAR_ARITHMETIC not defined when defining __ARM_FEATURE_SVE_BF16.

[fpetrogalli]

clang/utils/TableGen/SveEmitter.cpp

1095

Does it make sense to add a regression test to make sure this error is raised?

[c-rhodes]

Changes:

• Include arm_bf16.h if __ARM_FEATURE_BF16_SCALAR_ARITHMETIC is defined.

[fpetrogalli]

LGTM! Thanks.

clang/utils/TableGen/SveEmitter.cpp

1095

As discussed, this is not needed. The ACLE tests will catch this once we have set up the correct macros in the clang driver.

1104

nit: maybe add a comment specifying that this include is required in the ACLE specs.

[c-rhodes]

In D82178#2106847, @fpetrogalli wrote:

LGTM! Thanks.

Thanks for reviewing!

clang/include/clang/Basic/arm_sve.td

 def SVLD2_VNUM : SInst<"svld2_vnum[_{2}]", "2Pcl", "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_ld2", [IsStructLoad]>;
 def SVLD3_VNUM : SInst<"svld3_vnum[_{2}]", "3Pcl", "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_ld3", [IsStructLoad]>;
 def SVLD4_VNUM : SInst<"svld4_vnum[_{2}]", "4Pcl", "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_ld4", [IsStructLoad]>;
 
 // Load one octoword and replicate (scalar base)
 let ArchGuard = "defined(__ARM_FEATURE_SVE_MATMUL_FP64)" in {
   def SVLD1RO : SInst<"svld1ro[_{2}]", "dPc", "csilUcUsUiUlhfd", MergeNone, "aarch64_sve_ld1ro">;
 }
-let ArchGuard = "defined(__ARM_FEATURE_SVE_MATMUL_FP64) && defined(__ARM_FEATURE_BF16_SCALAR_ARITHMETIC)" in {
-  def SVLD1RO_BF : SInst<"svld1ro[_{2}]", "dPc", "b", MergeNone, "aarch64_sve_ld1ro">;
+let ArchGuard = "defined(__ARM_FEATURE_SVE_MATMUL_FP64) && defined(__ARM_FEATURE_SVE_BF16)" in {
+  def SVLD1RO_BF16 : SInst<"svld1ro[_{2}]", "dPc", "b", MergeNone, "aarch64_sve_ld1ro">;
 }
 
 let ArchGuard = "defined(__ARM_FEATURE_SVE_BF16)" in {
   def SVBFDOT        : SInst<"svbfdot[_{0}]",        "MMdd",  "b", MergeNone, "aarch64_sve_bfdot",        [IsOverloadNone]>;
   def SVBFMLALB      : SInst<"svbfmlalb[_{0}]",      "MMdd",  "b", MergeNone, "aarch64_sve_bfmlalb",      [IsOverloadNone]>;
   def SVBFMLALT      : SInst<"svbfmlalt[_{0}]",      "MMdd",  "b", MergeNone, "aarch64_sve_bfmlalt",      [IsOverloadNone]>;
   def SVBFMMLA       : SInst<"svbfmmla[_{0}]",       "MMdd",  "b", MergeNone, "aarch64_sve_bfmmla",       [IsOverloadNone]>;
   def SVBFDOT_N      : SInst<"svbfdot[_n_{0}]",      "MMda",  "b", MergeNone, "aarch64_sve_bfdot",        [IsOverloadNone]>;

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_bfmmla.c

-// RUN: %clang_cc1 -D__ARM_FEATURE_SVE -D__ARM_FEATURE_SVE_BF16 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -D__ARM_FEATURE_SVE -D__ARM_FEATURE_SVE_BF16 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -D__ARM_FEATURE_SVE -D__ARM_FEATURE_BF16_SCALAR_ARITHMETIC -D__ARM_FEATURE_SVE_BF16 -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -D__ARM_FEATURE_SVE -D__ARM_FEATURE_BF16_SCALAR_ARITHMETIC -D__ARM_FEATURE_SVE_BF16 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
 
 #include <arm_sve.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
 
 svfloat32_t test_bfmmla_f32(svfloat32_t x, svbfloat16_t y, svbfloat16_t z) {
   // CHECK-LABEL: @test_bfmmla_f32(
   // CHECK: %[[RET:.*]] = call <vscale x 4 x float> @llvm.aarch64.sve.bfmmla(<vscale x 4 x float> %x, <vscale x 8 x bfloat> %y, <vscale x 8 x bfloat> %z)
   // CHECK: ret <vscale x 4 x float> %[[RET]]
   return SVE_ACLE_FUNC(svbfmmla, _f32, , )(x, y, z);
 }

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_ld1ro-bfloat.c

-// RUN: %clang_cc1 -D__ARM_FEATURE_SVE_MATMUL_FP64 -D__ARM_FEATURE_BF16_SCALAR_ARITHMETIC -D__ARM_FEATURE_SVE -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -D__ARM_FEATURE_SVE_MATMUL_FP64 -D__ARM_FEATURE_BF16_SCALAR_ARITHMETIC -D__ARM_FEATURE_SVE -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -D__ARM_FEATURE_SVE_MATMUL_FP64 -D__ARM_FEATURE_SVE_BF16 -D__ARM_FEATURE_BF16_SCALAR_ARITHMETIC -D__ARM_FEATURE_SVE -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -D__ARM_FEATURE_SVE_MATMUL_FP64 -D__ARM_FEATURE_SVE_BF16 -D__ARM_FEATURE_BF16_SCALAR_ARITHMETIC -D__ARM_FEATURE_SVE -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
 
 #include <arm_sve.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

clang/utils/TableGen/SveEmitter.cpp

void SVEEmitter::createHeader(raw_ostream &OS) {
   OS << "typedef __SVInt8_t svint8_t;\n";
   OS << "typedef __SVInt16_t svint16_t;\n";
   OS << "typedef __SVInt32_t svint32_t;\n";
   OS << "typedef __SVInt64_t svint64_t;\n";
   OS << "typedef __SVUint8_t svuint8_t;\n";
   OS << "typedef __SVUint16_t svuint16_t;\n";
   OS << "typedef __SVUint32_t svuint32_t;\n";
   OS << "typedef __SVUint64_t svuint64_t;\n";
-  OS << "typedef __SVFloat16_t svfloat16_t;\n";
-  OS << "typedef __SVBFloat16_t svbfloat16_t;\n\n";
+  OS << "typedef __SVFloat16_t svfloat16_t;\n\n";
 
-  OS << "#ifdef __ARM_FEATURE_BF16_SCALAR_ARITHMETIC\n";
+  OS << "#if defined(__ARM_FEATURE_SVE_BF16) && "
+        "!defined(__ARM_FEATURE_BF16_SCALAR_ARITHMETIC)\n";
+  OS << "#error \"__ARM_FEATURE_BF16_SCALAR_ARITHMETIC must be defined when "
+        "__ARM_FEATURE_SVE_BF16 is defined\"\n";
+  OS << "#endif\n\n";
+
+  OS << "#if defined(__ARM_FEATURE_SVE_BF16)\n";
+  OS << "typedef __SVBFloat16_t svbfloat16_t;\n";
+  OS << "#endif\n\n";
+
+  OS << "#if defined(__ARM_FEATURE_BF16_SCALAR_ARITHMETIC)\n";
+  OS << "#include <arm_bf16.h>\n";
   OS << "typedef __bf16 bfloat16_t;\n";
   OS << "#endif\n\n";
 
   OS << "typedef __SVFloat32_t svfloat32_t;\n";
   OS << "typedef __SVFloat64_t svfloat64_t;\n";
   OS << "typedef __clang_svint8x2_t svint8x2_t;\n";
   OS << "typedef __clang_svint16x2_t svint16x2_t;\n";
   OS << "typedef __clang_svint32x2_t svint32x2_t;\n";