[clang][SVE] Activate macro `__ARM_FEATURE_SVE_VECTOR_OPERATORS`.

[fpetrogalli]

Summary

The macro is emitted when wargeting SVE code generation with the additional command line option -msve-vector-bits=<N>.

The behavior implied by the macro is described in sections "3.7.3.3. Behavior specific to SVE vectors" of the SVE ACLE (Version 00bet6) that can be found at https://developer.arm.com/documentation/100987/latest

[rengolin]

Simple and straightforward, with documentation! :)

LGTM, thanks!

[fpetrogalli]

NFC: update tests to use %clang_cc1 instead of %clang to prevent errors for missing includes: https://reviews.llvm.org/B77907

[peterwaller-arm]

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_VECTOR_OPERATORS-expected-error-on-address.c

7

[peterwaller-arm]

Suggestion: Where referencing sections you could include the title "3.7.3.3. Behavior specific to SVE vectors" instead of "3.7.3.3" for example. I think this makes it easier to spot misreferences and gives future souls a better chance to understand the context without indirection.

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_PREDICATE_OPERATORS.cpp

20

Do we need tests for unary operators, assignment and comparison operators?
(Page 28, item 3, subitems, 1, 3, 4)

[fpetrogalli]

I removed the enablement of __ARM_FEATURE_SVE_PREDICATE_OPERATORS as the codegen is incorrect.

I have extended testing of the codegen for __ARM_FEATURE_SVE_VECTOR_OPERATORS.

[fpetrogalli]

In the last update I removed the tests for __ARM_FEATURE_SVE_PREDICATE_OPERATORSbut forgot to remove the code that generates and tests the macro.

[fpetrogalli]

I have added more test coverage for the codegen of the examples mentioned in section 3.7.3.3 of the SVE ACLE. The tests are generic to work for -msve-vector-bits=128|...|2048.

[fpetrogalli]

@rengolin - thank you for looking into this. The patch has changed quite a bit since you approved it (faulty codegen for one of the macros, which I have removed from this patch). You might want to re-look at it.

[rsandifo-arm]

The tests look good to me FWIW. The Sema side is already covered by Sema/attr-arm-sve-vector-bits.c and the patch seems to test for the important ABI bits.

[rengolin]

Hi @fpetrogalli, the document is so dense that it took me a while to check the macros and I was still wrong.

Either I'm losing my skill to read Arm documents or folks are getting worse at writing them.

Giving this is a change that only affects SVE targets, and I have no way of independently verify codegen, I'm trusting you and the rest of Arm to make sure it's the right semantics. :)

Thanks!

clang/lib/Basic/Targets/AArch64.cpp

void AArch64TargetInfo::getTargetDefines(const LangOptions &Opts,
   }
 
   // All of the __sync_(bool|val)_compare_and_swap_(1|2|4|8) builtins work.
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8");
 
-  if (Opts.ArmSveVectorBits)
+  if (Opts.ArmSveVectorBits) {
     Builder.defineMacro("__ARM_FEATURE_SVE_BITS", Twine(Opts.ArmSveVectorBits));
+    Builder.defineMacro("__ARM_FEATURE_SVE_VECTOR_OPERATORS");
+    Builder.defineMacro("__ARM_FEATURE_SVE_PREDICATE_OPERATORS");
+  }
 }
 
 ArrayRef<Builtin::Info> AArch64TargetInfo::getTargetBuiltins() const {
   return llvm::makeArrayRef(BuiltinInfo, clang::AArch64::LastTSBuiltin -
                                              Builtin::FirstTSBuiltin);
 }
 
 bool AArch64TargetInfo::hasFeature(StringRef Feature) const {

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_PREDICATE_OPERATORS.c

+// RUN: %clang  -S -emit-llvm -c -O1 -o - %s -target aarch64-gnu-linux \
+// RUN: -march=armv8-a+sve -msve-vector-bits=256 | FileCheck %s
+// REQUIRES: aarch64-registered-target
+
+// Examples taken from section 3.7.3.4 of the SVE ACLE (Version
+// 00bet6) that can be found at
+// https://developer.arm.com/documentation/100987/latest
+
+#include <arm_sve.h>
+
+// Page 29, item 2.
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_PREDICATE_OPERATORS
+typedef svbool_t predty __attribute__((arm_sve_vector_bits(256)));
+// CHECK-LABEL: @a = dso_local local_unnamed_addr global <4 x i8> <i8 0, i8 1, i8 0, i8 0>
+predty a = {0, 1};
+#endif
+
+// Page 29, item 1.
+//
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_PREDICATE_OPERATORS
+typedef svbool_t pred __attribute__((arm_sve_vector_bits(256)));
+pred x;
+// CHECK-LABEL: @x = dso_local local_unnamed_addr global <4 x i8>
+// zeroinitializer
+// CHECK-LABEL: define dso_local i1 @f5()
+// CHECK-NEXT: entry:
+// CHECK-NEXT: %0 = load <4 x i8>, <4 x i8>* @x
+// CHECK-NEXT: insertelement <4 x i8> %0, i8 1, i32 1
+// CHECK-NEXT: store <4 x i8> %vecins, <4 x i8>* @x
+// CHECK-NEXT: extractelement <4 x i8> %0, i32 0
+// CHECK-NEXT: %tobool = icmp ne i8 %vecext, 0
+// CHECK-NEXT: ret i1 %tobool
+bool f5() {
+  x[1] = true;
+  return x[0];
+}
+#endif

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_PREDICATE_OPERATORS.cpp

+// RUN: %clang -x c++ -S -emit-llvm -c -O1 -o - %s -target aarch64-gnu-linux \
+// RUN: -march=armv8-a+sve -msve-vector-bits=256 | FileCheck %s
+// REQUIRES: aarch64-registered-target
+
+// Examples taken from section 3.7.3.4 of the SVE ACLE (Version
+// 00bet6) that can be found at
+// https://developer.arm.com/documentation/100987/latest
+
+#include <arm_sve.h>
+
+// Page 29, first paragraphs.
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_PREDICATE_OPERATORS
+// CHECK-LABEL: define {{.*}} <vscale x 16 x i1>
+// @_Z2f49__SVE_VLSIu10__SVBool_tLj256EES_(<vscale x 16 x i1> %x.coerce, <vscale
+// x 16 x i1> %y.coerce)
+typedef svbool_t pred __attribute__((arm_sve_vector_bits(256)));
+auto f4(pred x, pred y) { return x & y; } // Returns a pred
+#endif

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_VECTOR_OPERATORS-expected-error-on-address.c

+// RUN: not %clang  -S -emit-llvm -c -O1 -o - %s -target aarch64-gnu-linux \
+// RUN: -march=armv8-a+sve -msve-vector-bits=256 |& FileCheck %s
+// REQUIRES: aarch64-registered-target
+
+// Examples taken from section 3.7.3.3 of the SVE ACLE (Version
+// 00bet6) that can be found at
+// https://developer.arm.com/documentation/100987/latest
+
+#include <arm_sve.h>
+
+// Page 29, item 1. The compiler should emit a error when using
+// expression like &x[0] or &x[1].
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_PREDICATE_OPERATORS
+typedef svbool_t pred __attribute__((arm_sve_vector_bits(256)));
+pred x;
+void h(char *);
+void j() {
+  // CHECK: error: address of vector element requested
+  h((char)&x[0]);
+}
+#endif

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_VECTOR_OPERATORS.c

+// RUN: %clang        -S -emit-llvm -c -O1 -o - %s -target aarch64-gnu-linux \
+// RUN: -march=armv8-a+sve -msve-vector-bits=256 | FileCheck %s
+// REQUIRES: aarch64-registered-target
+
+// Examples taken from section 3.7.3.3 of the SVE ACLE (Version
+// 00bet6) that can be found at
+// https://developer.arm.com/documentation/100987/latest
+
+#include <arm_sve.h>
+
+// Page 27, item 1
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_VECTOR_OPERATORS
+// CHECK-LABEL: @x = dso_local local_unnamed_addr global <4 x i64> <i64 0, i64 1, i64 2, i64 3>, align 16
+typedef svint64_t vec256 __attribute__((arm_sve_vector_bits(256)));
+vec256 x = {0, 1, 2, 3};
+#endif
+
+// Page 27, item 2. We can not change the ABI of existing vector
+// types, including vec_int8.  That's why in the SVE ACLE, VLST is
+// distinct from, but mostly interchangeable with, the corresponding
+// GNUT. VLST is treated for ABI purposes like an SVE type but GNUT
+// continues to be a normal GNU vector type, with base Armv8-A PCS
+// rules.
+typedef int8_t vec_int8 __attribute__((vector_size(32)));
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_VECTOR_OPERATORS
+// CHECK-LABEL: {{.*}} void @f2(<32 x i8>* noalias nocapture sret(<32 x i8>) align 16 %agg.result, <32 x i8>* nocapture readonly %0)
+vec_int8 f2(vec_int8 x) { return svasrd_x(svptrue_b8(), x, 1); }
+#endif
+
+// Page 27, item 3.
+typedef int8_t vec1 __attribute__((vector_size(32)));
+void f3(vec1);
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_VECTOR_OPERATORS
+typedef svint8_t vec2 __attribute__((arm_sve_vector_bits(256)));
+// CHECK-LABEL: define dso_local void @g(<vscale x 16 x i8> %x.coerce)
+// CHECK-LABEL: declare dso_local void @f3(<32 x i8>*)
+void g(vec2 x) { f3(x); } // OK
+#endif

clang/test/CodeGen/aarch64-sve-acle-__ARM_FEATURE_SVE_VECTOR_OPERATORS.cpp

+// RUN: %clang -x c++ -S -emit-llvm -c -O1 -o - %s -target aarch64-gnu-linux \
+// RUN: -march=armv8-a+sve -msve-vector-bits=256 | FileCheck %s
+// RUN: %clang -x c++ -S -emit-llvm -c -O1 -o - %s -target aarch64-gnu-linux \
+// RUN: -march=armv8-a+sve -msve-vector-bits=512 | FileCheck %s --check-prefix=CHECK512
+// REQUIRES: aarch64-registered-target
+
+// Examples taken from section 3.7.3.3 of the SVE ACLE (Version
+// 00bet6) that can be found at
+// https://developer.arm.com/documentation/100987/latest
+
+#include <arm_sve.h>
+
+// Page 27, item 1.
+#if __ARM_FEATURE_SVE_BITS == 512 && __ARM_FEATURE_SVE_VECTOR_OPERATORS
+// CHECK512-LABEL: define {{.*}} <vscale x 4 x i32> @_Z1f9__SVE_VLSIu11__SVInt32_tLj512EES_(<vscale x 4 x i32> %x.coerce, <vscale x 4 x i32> %y.coerce)
+typedef svint32_t vec __attribute__((arm_sve_vector_bits(512)));
+auto f(vec x, vec y) { return x + y; } // Returns a vec.
+#endif
+
+// Page 27, item 3.
+typedef int8_t vec1 __attribute__((vector_size(32)));
+void f(vec1);
+#if __ARM_FEATURE_SVE_BITS == 256 && __ARM_FEATURE_SVE_VECTOR_OPERATORS
+typedef svint8_t vec2 __attribute__((arm_sve_vector_bits(256)));
+// CHECK-LABEL: @_Z1g9__SVE_VLSIu10__SVInt8_tLj256EE(
+void g(vec2 x) { f(x); } // OK
+#endif

clang/test/Preprocessor/aarch64-target-features.c

 
 // ================== Check BFloat16 Extensions.
 // RUN: %clang -target aarch64-arm-none-eabi -march=armv8.6-a+bf16 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-BFLOAT %s
 // CHECK-BFLOAT: __ARM_BF16_FORMAT_ALTERNATIVE 1
 // CHECK-BFLOAT: __ARM_FEATURE_BF16 1
 // CHECK-BFLOAT: __ARM_FEATURE_BF16_VECTOR_ARITHMETIC 1
 
 // ================== Check sve-vector-bits flag.
-// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=128 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS-128 %s
-// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=256 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS-256 %s
-// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=512 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS-512 %s
-// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=1024 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS-1024 %s
-// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=2048 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS-2048 %s
-// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=2048 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS-2048 %s
-// CHECK-SVE-VECTOR-BITS-128: __ARM_FEATURE_SVE_BITS 128
-// CHECK-SVE-VECTOR-BITS-256: __ARM_FEATURE_SVE_BITS 256
-// CHECK-SVE-VECTOR-BITS-512: __ARM_FEATURE_SVE_BITS 512
-// CHECK-SVE-VECTOR-BITS-1024: __ARM_FEATURE_SVE_BITS 1024
-// CHECK-SVE-VECTOR-BITS-2048: __ARM_FEATURE_SVE_BITS 2048
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=128  -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS -D#VBITS=128  %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=256  -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS -D#VBITS=256  %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=512  -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS -D#VBITS=512  %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=1024 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS -D#VBITS=1024 %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+sve -msve-vector-bits=2048 -x c -E -dM %s -o - 2>&1 | FileCheck -check-prefix=CHECK-SVE-VECTOR-BITS -D#VBITS=2048 %s
+// CHECK-SVE-VECTOR-BITS: __ARM_FEATURE_SVE_BITS [[#VBITS:]]
+// CHECK-SVE-VECTOR-BITS: __ARM_FEATURE_SVE_PREDICATE_OPERATORS 1
+// CHECK-SVE-VECTOR-BITS: __ARM_FEATURE_SVE_VECTOR_OPERATORS 1