https://github.com/Stylie777 created
https://github.com/llvm/llvm-project/pull/85203
When `+sve` is passed in the command line, if the Architecture being targeted
is V8.6A/V9.1A or later, `+f32mm` is also added. This enables FEAT_32MM,
however at the time of writing no CPU's support this. This leads to the
FEAT_32MM instructions being compiled for CPU's that do not support them.
This commit removes the automatic enablement, however the option is still able
to be used by passing `+f32mm`.
>From b5a0ad5d4b7ab3510cd00d178da245761e34d32d Mon Sep 17 00:00:00 2001
From: Jack Styles <jack.sty...@arm.com>
Date: Thu, 14 Mar 2024 10:06:05 +0000
Subject: [PATCH] [AArch64] Remove Automatic Enablement of FEAT_F32MM
When `+sve` is passed in the command line, if the Architecture being targeted
is V8.6A/V9.1A or later, `+f32mm` is also added. This enables FEAT_32MM,
however at the time of writing no CPU's support this. This leads to the
FEAT_32MM instructions being compiled for CPU's that do not support them.
This commit removes the automatic enablement, however the option is still able
to be used by passing `+f32mm`.
---
clang/test/Driver/aarch64-sve.c | 9 ++++-----
clang/test/Preprocessor/aarch64-target-features.c | 2 +-
llvm/docs/ReleaseNotes.rst | 1 +
llvm/lib/TargetParser/AArch64TargetParser.cpp | 5 -----
llvm/unittests/TargetParser/TargetParserTest.cpp | 9 +--------
5 files changed, 7 insertions(+), 19 deletions(-)
diff --git a/clang/test/Driver/aarch64-sve.c b/clang/test/Driver/aarch64-sve.c
index f34b2700deb91c..4a33c2e3c8d367 100644
--- a/clang/test/Driver/aarch64-sve.c
+++ b/clang/test/Driver/aarch64-sve.c
@@ -6,12 +6,11 @@
// RUN: %clang --target=aarch64 -march=armv8.6a -### -c %s 2>&1 | FileCheck
-check-prefix=GENERICV8A-NOSVE %s
// GENERICV8A-NOSVE-NOT: "-target-feature" "+sve"
-// The 32-bit floating point matrix multiply extension is enabled by default
-// for armv8.6-a targets (or later) with SVE, and can optionally be enabled for
-// any target from armv8.2a onwards (we don't enforce not using it with earlier
-// targets).
+// The 32-bit floating point matrix multiply extension is an optional feature
+// that can be used for any target from armv8.2a and onwards. This can be
+// enabled using the `+f32mm` option.`.
// RUN: %clang --target=aarch64 -march=armv8.6a -### -c %s 2>&1 |
FileCheck -check-prefix=NO-F32MM %s
-// RUN: %clang --target=aarch64 -march=armv8.6a+sve -### -c %s 2>&1 |
FileCheck -check-prefix=F32MM %s
+// RUN: %clang --target=aarch64 -march=armv8.6a+sve+f32mm -### -c %s 2>&1 |
FileCheck -check-prefix=F32MM %s
// RUN: %clang --target=aarch64 -march=armv8.5a+f32mm -### -c %s 2>&1 |
FileCheck -check-prefix=F32MM %s
// NO-F32MM-NOT: "-target-feature" "+f32mm"
// F32MM: "-target-feature" "+f32mm"
diff --git a/clang/test/Preprocessor/aarch64-target-features.c
b/clang/test/Preprocessor/aarch64-target-features.c
index 6ec4dcd60cf601..ab06cc7983ae85 100644
--- a/clang/test/Preprocessor/aarch64-target-features.c
+++ b/clang/test/Preprocessor/aarch64-target-features.c
@@ -196,7 +196,7 @@
// CHECK-8_6-NOT: __ARM_FEATURE_SHA3 1
// CHECK-8_6-NOT: __ARM_FEATURE_SM4 1
-// RUN: %clang -target aarch64-none-linux-gnu -march=armv8.6-a+sve -x c -E -dM
%s -o - | FileCheck --check-prefix=CHECK-SVE-8_6 %s
+// RUN: %clang -target aarch64-none-linux-gnu -march=armv8.6-a+sve+f32mm -x c
-E -dM %s -o - | FileCheck --check-prefix=CHECK-SVE-8_6 %s
// CHECK-SVE-8_6: __ARM_FEATURE_SVE 1
// CHECK-SVE-8_6: __ARM_FEATURE_SVE_BF16 1
// CHECK-SVE-8_6: __ARM_FEATURE_SVE_MATMUL_FP32 1
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 7be51730663bd1..b65a108a9b6a36 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -74,6 +74,7 @@ Changes to the AMDGPU Backend
Changes to the ARM Backend
--------------------------
+* FEAT_F32MM is no longer activated by default when using `+sve` on v8.6-A or
greater. The feature is still availble and can be using by adding `+f32mm` to
the command line options.
Changes to the AVR Backend
--------------------------
diff --git a/llvm/lib/TargetParser/AArch64TargetParser.cpp
b/llvm/lib/TargetParser/AArch64TargetParser.cpp
index e36832f563eed8..71099462d5ecff 100644
--- a/llvm/lib/TargetParser/AArch64TargetParser.cpp
+++ b/llvm/lib/TargetParser/AArch64TargetParser.cpp
@@ -186,11 +186,6 @@ void AArch64::ExtensionSet::enable(ArchExtKind E) {
// Special cases for dependencies which vary depending on the base
// architecture version.
if (BaseArch) {
- // +sve implies +f32mm if the base architecture is v8.6A+ or v9.1A+
- // It isn't the case in general that sve implies both f64mm and f32mm
- if (E == AEK_SVE && BaseArch->is_superset(ARMV8_6A))
- enable(AEK_F32MM);
-
// +fp16 implies +fp16fml for v8.4A+, but not v9.0-A+
if (E == AEK_FP16 && BaseArch->is_superset(ARMV8_4A) &&
!BaseArch->is_superset(ARMV9A))
diff --git a/llvm/unittests/TargetParser/TargetParserTest.cpp
b/llvm/unittests/TargetParser/TargetParserTest.cpp
index 3773f59a3c5af9..a21846f5b4940b 100644
--- a/llvm/unittests/TargetParser/TargetParserTest.cpp
+++ b/llvm/unittests/TargetParser/TargetParserTest.cpp
@@ -2314,13 +2314,6 @@ AArch64ExtensionDependenciesBaseArchTestParams
{},
{"aes", "sha2", "sha3", "sm4"}},
- // +sve implies +f32mm if the base architecture is v8.6A+ or v9.1A+,
but
- // not earlier architectures.
- {AArch64::ARMV8_5A, {"sve"}, {"sve"}, {"f32mm"}},
- {AArch64::ARMV9A, {"sve"}, {"sve"}, {"f32mm"}},
- {AArch64::ARMV8_6A, {"sve"}, {"sve", "f32mm"}, {}},
- {AArch64::ARMV9_1A, {"sve"}, {"sve", "f32mm"}, {}},
-
// +fp16 implies +fp16fml for v8.4A+, but not v9.0-A+
{AArch64::ARMV8_3A, {"fp16"}, {"fullfp16"}, {"fp16fml"}},
{AArch64::ARMV9A, {"fp16"}, {"fullfp16"}, {"fp16fml"}},
@@ -2487,7 +2480,7 @@ AArch64ExtensionDependenciesBaseCPUTestParams
{}},
{"cortex-a520",
{},
- {"v9.2a", "bf16", "crc", "dotprod", "f32mm",
"flagm",
+ {"v9.2a", "bf16", "crc", "dotprod", "flagm",
"fp-armv8", "fullfp16", "fp16fml", "i8mm", "lse", "mte",
"pauth", "perfmon", "predres", "ras", "rcpc", "rdm",
"sb", "neon", "ssbs", "sve", "sve2-bitperm",
"sve2"},
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