[AArch64] Added feature dependencies for SME2p1 to TargetParser

[Lukacma]

This patches adds missing target-feature dependencies for SME2.1

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[Lukacma]

Seems like I cannot add reviewers yet so I am tagging you for review @momchil-velikov @hassnaaHamdi @CarolineConcatto

[CarolineConcatto]

Hi @Lukacma ,
It would be nice if you can add a test with clang cc1 to show what was the problem you are trying to fix.
Without this change clang cc1 does not see/understand the SVE type sizes

[Lukacma]

Hello @CarolineConcatto ,

Yes I was thinking about this but I couldn't find a good way to directly test this. Ideally we would have some sme2p1 tests, which just wouldn't work when cc1 would be used, but we don't have that as far as I can tell. I could create a dummy test, which wouldn't pass without this change but that felt little odd to me. Therefore, I wanted to check if there is better way to test this fix I might have missed.

[CarolineConcatto]

Can it have a test for the sve types. Something like:

// RUN: %clang_cc1 -fclang-abi-compat=latest -triple aarch64-none-linux-gnu -target-feature +sme2p1  -S -disable-O0-optnone -Werror -Wall -emit-llvm -o - %s | opt -S -p mem2reg,instcombine,tailcallelim | FileCheck %s
// RUN: %clang_cc1 -fclang-abi-compat=latest -triple aarch64-none-linux-gnu -target-feature +sme2p1 -S -disable-O0-optnone -Werror -Wall -o /dev/null %s

#include <arm_sme.h>
svuint8_t foo(svuint8_t a)  {
   return a;
}
svfloat16x2_t foo(svuint16x2_t a)  {
   return a;
}

[Lukacma]

Yes it could be like that. I was just wondering if there is not a better way than creating dummy programs and seeing if they compile. We have a test in aarch64-implied-sme-features.c which tests this nicely like this :

// RUN: %clang -target aarch64-linux-gnu -march=armv8-a+sme %s -### 2>&1 | FileCheck %s --check-prefix=SME-IMPLY
// SME-IMPLY: "-target-feature" "+bf16"{{.*}} "-target-feature" "+sme"

Unfortunately this doesn't work with -cc1 and I was wondering if there is not a way to do something similiar for -cc1 that I am missing. If not I will create the dummy test.

[momchil-velikov]

Yes it could be like that. I was just wondering if there is not a better way than creating dummy programs and seeing if they compile. We have a test in aarch64-implied-sme-features.c which tests this nicely like this :

// RUN: %clang -target aarch64-linux-gnu -march=armv8-a+sme %s -### 2>&1 | FileCheck %s --check-prefix=SME-IMPLY
// SME-IMPLY: "-target-feature" "+bf16"{{.*}} "-target-feature" "+sme"

Unfortunately this doesn't work with -cc1 and I was wondering if there is not a way to do something similiar for -cc1 that I am missing. If not I will create the dummy test.

Add something like

// RUN: %clang_cc1  -triple aarch64-linux -target-feature +sme2p1 -S  -fsyntax-only -verify %s

#include <arm_sme.h>

void f(svfloat32_t x) {}

// expected-no-diagnostics

[llvmbot]

@llvm/pr-subscribers-clang

Author: None (Lukacma)

Changes

This patches adds missing target-feature dependencies for SME2.1

---

Full diff: https://github.com/llvm/llvm-project/pull/81860.diff

2 Files Affected:

• (added) clang/test/Sema/aarch64-sme2p1-diagnostics.c (+10)
• (modified) llvm/include/llvm/TargetParser/AArch64TargetParser.h (+1-1)

diff --git a/clang/test/Sema/aarch64-sme2p1-diagnostics.c b/clang/test/Sema/aarch64-sme2p1-diagnostics.c
new file mode 100644
index 00000000000000..a0adb040385815
--- /dev/null
+++ b/clang/test/Sema/aarch64-sme2p1-diagnostics.c
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu  -target-feature +sme2p1 -fsyntax-only -verify %s
+
+// REQUIRES: aarch64-registered-target
+#include "arm_sme.h"
+
+svuint8x2_t  test_sme2p1(svuint8x2_t  x) {
+  // expected-no-diagnostics
+  return x;
+}
+
diff --git a/llvm/include/llvm/TargetParser/AArch64TargetParser.h b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
index ed9944bcef23d0..7376ac98a2b095 100644
--- a/llvm/include/llvm/TargetParser/AArch64TargetParser.h
+++ b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
@@ -273,7 +273,7 @@ inline constexpr ExtensionInfo Extensions[] = {
     {"sme-i16i64", AArch64::AEK_SMEI16I64, "+sme-i16i64", "-sme-i16i64", FEAT_SME_I64, "+sme,+sme-i16i64,+bf16", 570},
     {"sme", AArch64::AEK_SME, "+sme", "-sme", FEAT_SME, "+sme,+bf16", 430},
     {"sme2", AArch64::AEK_SME2, "+sme2", "-sme2", FEAT_SME2, "+sme2,+sme,+bf16", 580},
-    {"sme2p1", AArch64::AEK_SME2p1, "+sme2p1", "-sme2p1", FEAT_INIT, "", 0},
+    {"sme2p1", AArch64::AEK_SME2p1, "+sme2p1", "-sme2p1", FEAT_INIT, "+sme2p1,+sme2,+sme,+bf16", 0},
     {"ssbs", AArch64::AEK_SSBS, "+ssbs", "-ssbs", FEAT_SSBS, "", 490},
     {"ssbs2", AArch64::AEK_NONE, {}, {}, FEAT_SSBS2, "+ssbs", 500},
     {"sve-bf16", AArch64::AEK_NONE, {}, {}, FEAT_SVE_BF16, "+sve,+bf16,+fullfp16,+fp-armv8,+neon", 320},

[Lukacma]

Testcase added

[CarolineConcatto]

Thank you @Lukacma

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