[clang] [llvm] [AArch64] Enable FEAT_SVE2p1 by default for Armv9.4-A and later (PR #120753)

[Jonathan Thackray via llvm-commits]

https://github.com/jthackray updated https://github.com/llvm/llvm-project/pull/120753

>From 519bcca2359ee9c89b12bac6e58eb955c79cd7bc Mon Sep 17 00:00:00 2001
From: Jonathan Thackray <jonathan.thackray at arm.com>
Date: Fri, 20 Dec 2024 14:50:37 +0000
Subject: [PATCH 1/2] [AArch64] Enable FEAT_SVE2p1 by default for Armv9.4-A and
 later.

The ArmARM says:
```
    "In an Armv9.4 implementation, if FEAT_SVE2 is implemented,
     FEAT_SVE2p1 is implemented."
```
Since FEAT_SVE2 is already enabled for Armv9.0-A and later,
then FEAT_SVE2p1 should also be enabled by default.
---
 clang/test/Driver/print-enabled-extensions/aarch64-armv9.4-a.c | 1 +
 clang/test/Driver/print-enabled-extensions/aarch64-armv9.5-a.c | 1 +
 llvm/lib/Target/AArch64/AArch64Features.td                     | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/clang/test/Driver/print-enabled-extensions/aarch64-armv9.4-a.c b/clang/test/Driver/print-enabled-extensions/aarch64-armv9.4-a.c
index 0032c926c22d96..1cfda6c996b9e3 100644
--- a/clang/test/Driver/print-enabled-extensions/aarch64-armv9.4-a.c
+++ b/clang/test/Driver/print-enabled-extensions/aarch64-armv9.4-a.c
@@ -58,6 +58,7 @@
 // CHECK-NEXT:     FEAT_SSBS, FEAT_SSBS2                                  Enable Speculative Store Bypass Safe bit
 // CHECK-NEXT:     FEAT_SVE                                               Enable Scalable Vector Extension (SVE) instructions
 // CHECK-NEXT:     FEAT_SVE2                                              Enable Scalable Vector Extension 2 (SVE2) instructions
+// CHECK-NEXT:     FEAT_SVE2p1                                            Enable Scalable Vector Extension 2.1 instructions
 // CHECK-NEXT:     FEAT_TLBIOS, FEAT_TLBIRANGE                            Enable Armv8.4-A TLB Range and Maintenance instructions
 // CHECK-NEXT:     FEAT_TRBE                                              Enable Trace Buffer Extension
 // CHECK-NEXT:     FEAT_TRF                                               Enable Armv8.4-A Trace extension
diff --git a/clang/test/Driver/print-enabled-extensions/aarch64-armv9.5-a.c b/clang/test/Driver/print-enabled-extensions/aarch64-armv9.5-a.c
index be24bd0bbddb68..76c8b34a56b75b 100644
--- a/clang/test/Driver/print-enabled-extensions/aarch64-armv9.5-a.c
+++ b/clang/test/Driver/print-enabled-extensions/aarch64-armv9.5-a.c
@@ -61,6 +61,7 @@
 // CHECK-NEXT:     FEAT_SSBS, FEAT_SSBS2                                  Enable Speculative Store Bypass Safe bit
 // CHECK-NEXT:     FEAT_SVE                                               Enable Scalable Vector Extension (SVE) instructions
 // CHECK-NEXT:     FEAT_SVE2                                              Enable Scalable Vector Extension 2 (SVE2) instructions
+// CHECK-NEXT:     FEAT_SVE2p1                                            Enable Scalable Vector Extension 2.1 instructions
 // CHECK-NEXT:     FEAT_TLBIOS, FEAT_TLBIRANGE                            Enable Armv8.4-A TLB Range and Maintenance instructions
 // CHECK-NEXT:     FEAT_TRBE                                              Enable Trace Buffer Extension
 // CHECK-NEXT:     FEAT_TRF                                               Enable Armv8.4-A Trace extension
diff --git a/llvm/lib/Target/AArch64/AArch64Features.td b/llvm/lib/Target/AArch64/AArch64Features.td
index 3a6bef81f4a0d8..96473e55f01d8e 100644
--- a/llvm/lib/Target/AArch64/AArch64Features.td
+++ b/llvm/lib/Target/AArch64/AArch64Features.td
@@ -872,7 +872,7 @@ def HasV9_3aOps : Architecture64<9, 3, "a", "v9.3a",
   [HasV8_8aOps, HasV9_2aOps],
   !listconcat(HasV9_2aOps.DefaultExts, [FeatureMOPS, FeatureHBC])>;
 def HasV9_4aOps : Architecture64<9, 4, "a", "v9.4a",
-  [HasV8_9aOps, HasV9_3aOps],
+  [HasV8_9aOps, HasV9_3aOps, FeatureSVE2p1],
   !listconcat(HasV9_3aOps.DefaultExts, [FeatureSPECRES2, FeatureCSSC,
     FeatureRASv2])>;
 def HasV9_5aOps : Architecture64<9, 5, "a", "v9.5a",

>From 15a2f3922bec4ccc6472f3eb2029c66f9ef6d834 Mon Sep 17 00:00:00 2001
From: Jonathan Thackray <jonathan.thackray at arm.com>
Date: Fri, 20 Dec 2024 16:13:53 +0000
Subject: [PATCH 2/2] fixup! [AArch64] Enable FEAT_SVE2p1 by default for
 Armv9.4-A and later.

---
 llvm/lib/Target/AArch64/AArch64Features.td | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Target/AArch64/AArch64Features.td b/llvm/lib/Target/AArch64/AArch64Features.td
index 96473e55f01d8e..41eb9a73bd013d 100644
--- a/llvm/lib/Target/AArch64/AArch64Features.td
+++ b/llvm/lib/Target/AArch64/AArch64Features.td
@@ -872,9 +872,9 @@ def HasV9_3aOps : Architecture64<9, 3, "a", "v9.3a",
   [HasV8_8aOps, HasV9_2aOps],
   !listconcat(HasV9_2aOps.DefaultExts, [FeatureMOPS, FeatureHBC])>;
 def HasV9_4aOps : Architecture64<9, 4, "a", "v9.4a",
-  [HasV8_9aOps, HasV9_3aOps, FeatureSVE2p1],
+  [HasV8_9aOps, HasV9_3aOps],
   !listconcat(HasV9_3aOps.DefaultExts, [FeatureSPECRES2, FeatureCSSC,
-    FeatureRASv2])>;
+    FeatureRASv2, FeatureSVE2p1])>;
 def HasV9_5aOps : Architecture64<9, 5, "a", "v9.5a",
   [HasV9_4aOps, FeatureCPA],
   !listconcat(HasV9_4aOps.DefaultExts, [FeatureCPA,  FeatureLUT, FeatureFAMINMAX])>;