[FMV][AArch64] Unify features memtag and memtag2. #112511

labrinea · 2024-10-16T09:49:40Z

If we split these features in the compiler (see relevant pull request #109299), we would only be able to hand-write a 'memtag2' version using inline assembly since the compiler cannot generate the instructions that become available with FEAT_MTE2. However these instructions only work at Exception Level 1, so they would be unusable since FMV is a user space facility. I am therefore unifying them.

Approved in ACLE as ARM-software/acle#351

If we split these features in the compiler (see relevant pull request llvm#109299), we would only be able to hand-write a 'memtag2' version using inline assembly since the compiler cannot generate the instructions that become available with FEAT_MTE2. However these instructions only work at Exception Level 1, so they would be unusable since FMV is a user space facility. I am therefore unifying them. Approved in ACLE as ARM-software/acle#351

llvmbot · 2024-10-16T09:50:19Z

@llvm/pr-subscribers-backend-aarch64

Author: Alexandros Lamprineas (labrinea)

Changes

If we split these features in the compiler (see relevant pull request #109299), we would only be able to hand-write a 'memtag2' version using inline assembly since the compiler cannot generate the instructions that become available with FEAT_MTE2. However these instructions only work at Exception Level 1, so they would be unusable since FMV is a user space facility. I am therefore unifying them.

Approved in ACLE as ARM-software/acle#351

Full diff: https://github.com/llvm/llvm-project/pull/112511.diff

12 Files Affected:

(modified) clang/include/clang/Basic/AttrDocs.td (+1-1)
(modified) clang/lib/Basic/Targets/AArch64.cpp (+1-1)
(modified) clang/test/CodeGen/aarch64-cpu-supports-target.c (+1-1)
(modified) clang/test/CodeGen/aarch64-cpu-supports.c (+10-5)
(modified) clang/test/CodeGen/aarch64-fmv-dependencies.c (+3-6)
(modified) clang/test/CodeGen/attr-target-clones-aarch64.c (+10-10)
(modified) clang/test/CodeGen/attr-target-version.c (+8-8)
(modified) clang/test/Sema/attr-target-clones-aarch64.c (+1-1)
(modified) compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc (+1-1)
(modified) compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc (+1-3)
(modified) llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc (+1-1)
(modified) llvm/lib/Target/AArch64/AArch64FMV.td (+1-2)

diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index b1512e22ee2dd4..ee8126cadae232 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -2669,7 +2669,7 @@ sign. For example:
 
   .. code-block:: c++
 
-    __attribute__((target_clones("sha2+memtag2", "fcma+sve2-pmull128")))
+    __attribute__((target_clones("sha2+memtag", "fcma+sve2-pmull128")))
     void foo() {}
 
 For every multiversioned function a ``default`` (fallback) implementation
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index b96fab978a3fcb..3dbba2b4d25bd6 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -784,7 +784,7 @@ bool AArch64TargetInfo::hasFeature(StringRef Feature) const {
       .Case("sme-fa64", HasSMEFA64)
       .Case("sme-f16f16", HasSMEF16F16)
       .Case("sme-b16b16", HasSMEB16B16)
-      .Cases("memtag", "memtag2", HasMTE)
+      .Case("memtag", HasMTE)
       .Case("sb", HasSB)
       .Case("predres", HasPredRes)
       .Cases("ssbs", "ssbs2", HasSSBS)
diff --git a/clang/test/CodeGen/aarch64-cpu-supports-target.c b/clang/test/CodeGen/aarch64-cpu-supports-target.c
index 28187bcf745331..5186cab92a921d 100644
--- a/clang/test/CodeGen/aarch64-cpu-supports-target.c
+++ b/clang/test/CodeGen/aarch64-cpu-supports-target.c
@@ -17,7 +17,7 @@ int check_all_feature() {
     return 7;
   else if (__builtin_cpu_supports("sve2-bitperm+sve2-sha3+sve2-sm4"))
     return 8;
-  else if (__builtin_cpu_supports("sme+memtag+memtag2+memtag3+sb"))
+  else if (__builtin_cpu_supports("sme+memtag+memtag3+sb"))
     return 9;
   else if (__builtin_cpu_supports("predres+ssbs+ssbs2+bti+ls64+ls64_v"))
     return 10;
diff --git a/clang/test/CodeGen/aarch64-cpu-supports.c b/clang/test/CodeGen/aarch64-cpu-supports.c
index 823bf369df6fcc..dc96c929fdf4cb 100644
--- a/clang/test/CodeGen/aarch64-cpu-supports.c
+++ b/clang/test/CodeGen/aarch64-cpu-supports.c
@@ -1,9 +1,10 @@
-// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals --version 2
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals --global-value-regex ".*"
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
+//.
 // CHECK: @__aarch64_cpu_features = external dso_local global { i64 }
-// CHECK-LABEL: define dso_local i32 @main
-// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+//.
+// CHECK-LABEL: @main(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    [[RETVAL:%.*]] = alloca i32, align 4
 // CHECK-NEXT:    store i32 0, ptr [[RETVAL]], align 4
@@ -17,8 +18,8 @@
 // CHECK-NEXT:    br label [[RETURN:%.*]]
 // CHECK:       if.end:
 // CHECK-NEXT:    [[TMP4:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
-// CHECK-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 9070970929152
-// CHECK-NEXT:    [[TMP6:%.*]] = icmp eq i64 [[TMP5]], 9070970929152
+// CHECK-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 17867063951360
+// CHECK-NEXT:    [[TMP6:%.*]] = icmp eq i64 [[TMP5]], 17867063951360
 // CHECK-NEXT:    [[TMP7:%.*]] = and i1 true, [[TMP6]]
 // CHECK-NEXT:    br i1 [[TMP7]], label [[IF_THEN1:%.*]], label [[IF_END2:%.*]]
 // CHECK:       if.then1:
@@ -60,3 +61,7 @@ int main(void) {
 
   return 0;
 }
+//.
+// CHECK: [[META0:![0-9]+]] = !{i32 1, !"wchar_size", i32 4}
+// CHECK: [[META1:![0-9]+]] = !{!"{{.*}}clang version {{.*}}"}
+//.
diff --git a/clang/test/CodeGen/aarch64-fmv-dependencies.c b/clang/test/CodeGen/aarch64-fmv-dependencies.c
index f4229a5d233970..9aca1b7a9daf6e 100644
--- a/clang/test/CodeGen/aarch64-fmv-dependencies.c
+++ b/clang/test/CodeGen/aarch64-fmv-dependencies.c
@@ -72,13 +72,10 @@ __attribute__((target_version("ls64"))) int fmv(void) { return 0; }
 // CHECK: define dso_local i32 @fmv._Mlse() #[[lse:[0-9]+]] {
 __attribute__((target_version("lse"))) int fmv(void) { return 0; }
 
-// CHECK: define dso_local i32 @fmv._Mmemtag() #[[ATTR0:[0-9]+]] {
+// CHECK: define dso_local i32 @fmv._Mmemtag() #[[memtag:[0-9]+]] {
 __attribute__((target_version("memtag"))) int fmv(void) { return 0; }
 
-// CHECK: define dso_local i32 @fmv._Mmemtag2() #[[memtag2:[0-9]+]] {
-__attribute__((target_version("memtag2"))) int fmv(void) { return 0; }
-
-// CHECK: define dso_local i32 @fmv._Mmemtag3() #[[memtag2:[0-9]+]] {
+// CHECK: define dso_local i32 @fmv._Mmemtag3() #[[memtag:[0-9]+]] {
 __attribute__((target_version("memtag3"))) int fmv(void) { return 0; }
 
 // CHECK: define dso_local i32 @fmv._Mmops() #[[mops:[0-9]+]] {
@@ -200,7 +197,7 @@ int caller() {
 // CHECK: attributes #[[jscvt]] = { {{.*}} "target-features"="+fp-armv8,+jsconv,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[ls64]] = { {{.*}} "target-features"="+fp-armv8,+ls64,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[lse]] = { {{.*}} "target-features"="+fp-armv8,+lse,+neon,+outline-atomics,+v8a"
-// CHECK: attributes #[[memtag2]] = { {{.*}} "target-features"="+fp-armv8,+mte,+neon,+outline-atomics,+v8a"
+// CHECK: attributes #[[memtag]] = { {{.*}} "target-features"="+fp-armv8,+mte,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[mops]] = { {{.*}} "target-features"="+fp-armv8,+mops,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[pmull]] = { {{.*}} "target-features"="+aes,+fp-armv8,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[predres]] = { {{.*}} "target-features"="+fp-armv8,+neon,+outline-atomics,+predres,+v8a"
diff --git a/clang/test/CodeGen/attr-target-clones-aarch64.c b/clang/test/CodeGen/attr-target-clones-aarch64.c
index 292e544139e3ff..c490682e310aff 100644
--- a/clang/test/CodeGen/attr-target-clones-aarch64.c
+++ b/clang/test/CodeGen/attr-target-clones-aarch64.c
@@ -4,10 +4,10 @@
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +mte -target-feature +bti -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK-MTE-BTI
 
 int __attribute__((target_clones("lse+aes", "sve2"))) ftc(void) { return 0; }
-int __attribute__((target_clones("sha2", "sha2+memtag2", " default "))) ftc_def(void) { return 1; }
+int __attribute__((target_clones("sha2", "sha2+memtag", " default "))) ftc_def(void) { return 1; }
 int __attribute__((target_clones("sha2", "default"))) ftc_dup1(void) { return 2; }
 int __attribute__((target_clones("fp", "crc+dotprod"))) ftc_dup2(void) { return 3; }
-int __attribute__((target_clones("memtag2", "bti"))) ftc_dup3(void) { return 4; }
+int __attribute__((target_clones("memtag", "bti"))) ftc_dup3(void) { return 4; }
 int foo() {
   return ftc() + ftc_def() + ftc_dup1() + ftc_dup2() + ftc_dup3();
 }
@@ -90,7 +90,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
-// CHECK-LABEL: define {{[^@]+}}@ftc_def._Mmemtag2Msha2
+// CHECK-LABEL: define {{[^@]+}}@ftc_def._MmemtagMsha2
 // CHECK-SAME: () #[[ATTR3:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 1
@@ -105,7 +105,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-NEXT:    [[TMP3:%.*]] = and i1 true, [[TMP2]]
 // CHECK-NEXT:    br i1 [[TMP3]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE:%.*]]
 // CHECK:       resolver_return:
-// CHECK-NEXT:    ret ptr @ftc_def._Mmemtag2Msha2
+// CHECK-NEXT:    ret ptr @ftc_def._MmemtagMsha2
 // CHECK:       resolver_else:
 // CHECK-NEXT:    [[TMP4:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
 // CHECK-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 4096
@@ -176,7 +176,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
-// CHECK-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag2
+// CHECK-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag
 // CHECK-SAME: () #[[ATTR6:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 4
@@ -206,7 +206,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-NEXT:    [[TMP7:%.*]] = and i1 true, [[TMP6]]
 // CHECK-NEXT:    br i1 [[TMP7]], label [[RESOLVER_RETURN1:%.*]], label [[RESOLVER_ELSE2:%.*]]
 // CHECK:       resolver_return1:
-// CHECK-NEXT:    ret ptr @ftc_dup3._Mmemtag2
+// CHECK-NEXT:    ret ptr @ftc_dup3._Mmemtag
 // CHECK:       resolver_else2:
 // CHECK-NEXT:    ret ptr @ftc_dup3.default
 //
@@ -547,7 +547,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK-MTE-BTI: Function Attrs: noinline nounwind optnone
-// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_def._Mmemtag2Msha2
+// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_def._MmemtagMsha2
 // CHECK-MTE-BTI-SAME: () #[[ATTR2]] {
 // CHECK-MTE-BTI-NEXT:  entry:
 // CHECK-MTE-BTI-NEXT:    ret i32 1
@@ -562,7 +562,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-MTE-BTI-NEXT:    [[TMP3:%.*]] = and i1 true, [[TMP2]]
 // CHECK-MTE-BTI-NEXT:    br i1 [[TMP3]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE:%.*]]
 // CHECK-MTE-BTI:       resolver_return:
-// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_def._Mmemtag2Msha2
+// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_def._MmemtagMsha2
 // CHECK-MTE-BTI:       resolver_else:
 // CHECK-MTE-BTI-NEXT:    [[TMP4:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
 // CHECK-MTE-BTI-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 4096
@@ -633,7 +633,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK-MTE-BTI: Function Attrs: noinline nounwind optnone
-// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag2
+// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag
 // CHECK-MTE-BTI-SAME: () #[[ATTR5:[0-9]+]] {
 // CHECK-MTE-BTI-NEXT:  entry:
 // CHECK-MTE-BTI-NEXT:    ret i32 4
@@ -663,7 +663,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-MTE-BTI-NEXT:    [[TMP7:%.*]] = and i1 true, [[TMP6]]
 // CHECK-MTE-BTI-NEXT:    br i1 [[TMP7]], label [[RESOLVER_RETURN1:%.*]], label [[RESOLVER_ELSE2:%.*]]
 // CHECK-MTE-BTI:       resolver_return1:
-// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_dup3._Mmemtag2
+// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_dup3._Mmemtag
 // CHECK-MTE-BTI:       resolver_else2:
 // CHECK-MTE-BTI-NEXT:    ret ptr @ftc_dup3.default
 //
diff --git a/clang/test/CodeGen/attr-target-version.c b/clang/test/CodeGen/attr-target-version.c
index 22a53c82bfbf9f..0e2c7ad99d81bb 100644
--- a/clang/test/CodeGen/attr-target-version.c
+++ b/clang/test/CodeGen/attr-target-version.c
@@ -34,7 +34,7 @@ inline int __attribute__((target_version("rcpc+frintts"))) fmv_inline(void) { re
 inline int __attribute__((target_version("sve+sve-bf16"))) fmv_inline(void) { return 4; }
 inline int __attribute__((target_version("sve2-aes+sve2-sha3"))) fmv_inline(void) { return 5; }
 inline int __attribute__((target_version("sve2+sve2-pmull128+sve2-bitperm"))) fmv_inline(void) { return 9; }
-inline int __attribute__((target_version("sve2-sm4+memtag2"))) fmv_inline(void) { return 10; }
+inline int __attribute__((target_version("sve2-sm4+memtag"))) fmv_inline(void) { return 10; }
 inline int __attribute__((target_version("memtag3+rcpc3+mops"))) fmv_inline(void) { return 11; }
 inline int __attribute__((target_version("aes+dotprod"))) fmv_inline(void) { return 13; }
 inline int __attribute__((target_version("simd+fp16fml"))) fmv_inline(void) { return 14; }
@@ -500,8 +500,8 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 // CHECK-NEXT:    ret ptr @fmv._McrcMls64
 // CHECK:       resolver_else6:
 // CHECK-NEXT:    [[TMP16:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
-// CHECK-NEXT:    [[TMP17:%.*]] = and i64 [[TMP16]], 8796093022216
-// CHECK-NEXT:    [[TMP18:%.*]] = icmp eq i64 [[TMP17]], 8796093022216
+// CHECK-NEXT:    [[TMP17:%.*]] = and i64 [[TMP16]], 17592186044424
+// CHECK-NEXT:    [[TMP18:%.*]] = icmp eq i64 [[TMP17]], 17592186044424
 // CHECK-NEXT:    [[TMP19:%.*]] = and i1 true, [[TMP18]]
 // CHECK-NEXT:    br i1 [[TMP19]], label [[RESOLVER_RETURN7:%.*]], label [[RESOLVER_ELSE8:%.*]]
 // CHECK:       resolver_return7:
@@ -729,7 +729,7 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
-// CHECK-LABEL: define {{[^@]+}}@fmv_inline._Mmemtag2Msve2-sm4
+// CHECK-LABEL: define {{[^@]+}}@fmv_inline._MmemtagMsve2-sm4
 // CHECK-SAME: () #[[ATTR34:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 10
@@ -751,21 +751,21 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 //
 // CHECK: Function Attrs: noinline nounwind optnone
 // CHECK-LABEL: define {{[^@]+}}@fmv_inline._Mfp16fmlMsimd
-// CHECK-SAME: () #[[ATTR4]] {
+// CHECK-SAME: () #[[ATTR36:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 14
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
 // CHECK-LABEL: define {{[^@]+}}@fmv_inline._MfpMsm4
-// CHECK-SAME: () #[[ATTR36:[0-9]+]] {
+// CHECK-SAME: () #[[ATTR37:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 15
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
 // CHECK-LABEL: define {{[^@]+}}@fmv_inline._MlseMrdm
-// CHECK-SAME: () #[[ATTR37:[0-9]+]] {
+// CHECK-SAME: () #[[ATTR38:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 16
 //
@@ -826,7 +826,7 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 // CHECK-NEXT:    [[TMP23:%.*]] = and i1 true, [[TMP22]]
 // CHECK-NEXT:    br i1 [[TMP23]], label [[RESOLVER_RETURN9:%.*]], label [[RESOLVER_ELSE10:%.*]]
 // CHECK:       resolver_return9:
-// CHECK-NEXT:    ret ptr @fmv_inline._Mmemtag2Msve2-sm4
+// CHECK-NEXT:    ret ptr @fmv_inline._MmemtagMsve2-sm4
 // CHECK:       resolver_else10:
 // CHECK-NEXT:    [[TMP24:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
 // CHECK-NEXT:    [[TMP25:%.*]] = and i64 [[TMP24]], 1236950581248
diff --git a/clang/test/Sema/attr-target-clones-aarch64.c b/clang/test/Sema/attr-target-clones-aarch64.c
index 2765c06c68fbb8..191ca9ba96506d 100644
--- a/clang/test/Sema/attr-target-clones-aarch64.c
+++ b/clang/test/Sema/attr-target-clones-aarch64.c
@@ -22,7 +22,7 @@ int __attribute__((target_clones("rng", "fp16fml+fp", "default"))) redecl4(void)
 // expected-error@+3 {{'target_clones' attribute does not match previous declaration}}
 // expected-note@-2 {{previous declaration is here}}
 // expected-warning@+1 {{version list contains entries that don't impact code generation}}
-int __attribute__((target_clones("dgh+memtag+rpres", "ebf16+dpb", "default"))) redecl4(void) { return 1; }
+int __attribute__((target_clones("dgh+rpres", "ebf16+dpb", "default"))) redecl4(void) { return 1; }
 
 int __attribute__((target_version("flagm2"))) redef2(void) { return 1; }
 // expected-error@+2 {{multiversioned function redeclarations require identical target attributes}}
diff --git a/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc b/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc
index bb1875fe9f72c8..7af7f42517d1fb 100644
--- a/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc
+++ b/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc
@@ -65,7 +65,7 @@ enum CPUFeatures {
   FEAT_SVE_SHA3,
   FEAT_SVE_SM4,
   FEAT_SME,
-  FEAT_MEMTAG,
+  RESERVED_FEAT_MEMTAG, // previously used and now ABI legacy
   FEAT_MEMTAG2,
   FEAT_MEMTAG3,
   FEAT_SB,
diff --git a/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc b/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc
index a9befd7f3e56d7..0f1e9dd85303cf 100644
--- a/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc
+++ b/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc
@@ -45,10 +45,8 @@ static void __init_cpu_features_constructor(unsigned long hwcap,
     setCPUFeature(FEAT_SB);
   if (hwcap & HWCAP_SSBS)
     setCPUFeature(FEAT_SSBS2);
-  if (hwcap2 & HWCAP2_MTE) {
-    setCPUFeature(FEAT_MEMTAG);
+  if (hwcap2 & HWCAP2_MTE)
     setCPUFeature(FEAT_MEMTAG2);
-  }
   if (hwcap2 & HWCAP2_MTE3)
     setCPUFeature(FEAT_MEMTAG3);
   if (hwcap2 & HWCAP2_SVEAES)
diff --git a/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc b/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc
index bb1875fe9f72c8..7af7f42517d1fb 100644
--- a/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc
+++ b/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc
@@ -65,7 +65,7 @@ enum CPUFeatures {
   FEAT_SVE_SHA3,
   FEAT_SVE_SM4,
   FEAT_SME,
-  FEAT_MEMTAG,
+  RESERVED_FEAT_MEMTAG, // previously used and now ABI legacy
   FEAT_MEMTAG2,
   FEAT_MEMTAG3,
   FEAT_SB,
diff --git a/llvm/lib/Target/AArch64/AArch64FMV.td b/llvm/lib/Target/AArch64/AArch64FMV.td
index c063d3f38ba19c..5674e4dbd56bb7 100644
--- a/llvm/lib/Target/AArch64/AArch64FMV.td
+++ b/llvm/lib/Target/AArch64/AArch64FMV.td
@@ -60,8 +60,7 @@ def : FMVExtension<"i8mm", "FEAT_I8MM", "+i8mm", 270>;
 def : FMVExtension<"jscvt", "FEAT_JSCVT", "+fp-armv8,+neon,+jsconv", 210>;
 def : FMVExtension<"ls64", "FEAT_LS64_ACCDATA", "+ls64", 520>;
 def : FMVExtension<"lse", "FEAT_LSE", "+lse", 80>;
-def : FMVExtension<"memtag", "FEAT_MEMTAG", "", 440>;
-def : FMVExtension<"memtag2", "FEAT_MEMTAG2", "+mte", 450>;
+def : FMVExtension<"memtag", "FEAT_MEMTAG2", "+mte", 440>;
 def : FMVExtension<"memtag3", "FEAT_MEMTAG3", "+mte", 460>;
 def : FMVExtension<"mops", "FEAT_MOPS", "+mops", 650>;
 def : FMVExtension<"pmull", "FEAT_PMULL", "+aes,+fp-armv8,+neon", 160>;

llvmbot · 2024-10-16T09:50:20Z

@llvm/pr-subscribers-clang

Author: Alexandros Lamprineas (labrinea)

Changes

If we split these features in the compiler (see relevant pull request #109299), we would only be able to hand-write a 'memtag2' version using inline assembly since the compiler cannot generate the instructions that become available with FEAT_MTE2. However these instructions only work at Exception Level 1, so they would be unusable since FMV is a user space facility. I am therefore unifying them.

Approved in ACLE as ARM-software/acle#351

Full diff: https://github.com/llvm/llvm-project/pull/112511.diff

12 Files Affected:

(modified) clang/include/clang/Basic/AttrDocs.td (+1-1)
(modified) clang/lib/Basic/Targets/AArch64.cpp (+1-1)
(modified) clang/test/CodeGen/aarch64-cpu-supports-target.c (+1-1)
(modified) clang/test/CodeGen/aarch64-cpu-supports.c (+10-5)
(modified) clang/test/CodeGen/aarch64-fmv-dependencies.c (+3-6)
(modified) clang/test/CodeGen/attr-target-clones-aarch64.c (+10-10)
(modified) clang/test/CodeGen/attr-target-version.c (+8-8)
(modified) clang/test/Sema/attr-target-clones-aarch64.c (+1-1)
(modified) compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc (+1-1)
(modified) compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc (+1-3)
(modified) llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc (+1-1)
(modified) llvm/lib/Target/AArch64/AArch64FMV.td (+1-2)

diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index b1512e22ee2dd4..ee8126cadae232 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -2669,7 +2669,7 @@ sign. For example:
 
   .. code-block:: c++
 
-    __attribute__((target_clones("sha2+memtag2", "fcma+sve2-pmull128")))
+    __attribute__((target_clones("sha2+memtag", "fcma+sve2-pmull128")))
     void foo() {}
 
 For every multiversioned function a ``default`` (fallback) implementation
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index b96fab978a3fcb..3dbba2b4d25bd6 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -784,7 +784,7 @@ bool AArch64TargetInfo::hasFeature(StringRef Feature) const {
       .Case("sme-fa64", HasSMEFA64)
       .Case("sme-f16f16", HasSMEF16F16)
       .Case("sme-b16b16", HasSMEB16B16)
-      .Cases("memtag", "memtag2", HasMTE)
+      .Case("memtag", HasMTE)
       .Case("sb", HasSB)
       .Case("predres", HasPredRes)
       .Cases("ssbs", "ssbs2", HasSSBS)
diff --git a/clang/test/CodeGen/aarch64-cpu-supports-target.c b/clang/test/CodeGen/aarch64-cpu-supports-target.c
index 28187bcf745331..5186cab92a921d 100644
--- a/clang/test/CodeGen/aarch64-cpu-supports-target.c
+++ b/clang/test/CodeGen/aarch64-cpu-supports-target.c
@@ -17,7 +17,7 @@ int check_all_feature() {
     return 7;
   else if (__builtin_cpu_supports("sve2-bitperm+sve2-sha3+sve2-sm4"))
     return 8;
-  else if (__builtin_cpu_supports("sme+memtag+memtag2+memtag3+sb"))
+  else if (__builtin_cpu_supports("sme+memtag+memtag3+sb"))
     return 9;
   else if (__builtin_cpu_supports("predres+ssbs+ssbs2+bti+ls64+ls64_v"))
     return 10;
diff --git a/clang/test/CodeGen/aarch64-cpu-supports.c b/clang/test/CodeGen/aarch64-cpu-supports.c
index 823bf369df6fcc..dc96c929fdf4cb 100644
--- a/clang/test/CodeGen/aarch64-cpu-supports.c
+++ b/clang/test/CodeGen/aarch64-cpu-supports.c
@@ -1,9 +1,10 @@
-// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals --version 2
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals --global-value-regex ".*"
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
+//.
 // CHECK: @__aarch64_cpu_features = external dso_local global { i64 }
-// CHECK-LABEL: define dso_local i32 @main
-// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+//.
+// CHECK-LABEL: @main(
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    [[RETVAL:%.*]] = alloca i32, align 4
 // CHECK-NEXT:    store i32 0, ptr [[RETVAL]], align 4
@@ -17,8 +18,8 @@
 // CHECK-NEXT:    br label [[RETURN:%.*]]
 // CHECK:       if.end:
 // CHECK-NEXT:    [[TMP4:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
-// CHECK-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 9070970929152
-// CHECK-NEXT:    [[TMP6:%.*]] = icmp eq i64 [[TMP5]], 9070970929152
+// CHECK-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 17867063951360
+// CHECK-NEXT:    [[TMP6:%.*]] = icmp eq i64 [[TMP5]], 17867063951360
 // CHECK-NEXT:    [[TMP7:%.*]] = and i1 true, [[TMP6]]
 // CHECK-NEXT:    br i1 [[TMP7]], label [[IF_THEN1:%.*]], label [[IF_END2:%.*]]
 // CHECK:       if.then1:
@@ -60,3 +61,7 @@ int main(void) {
 
   return 0;
 }
+//.
+// CHECK: [[META0:![0-9]+]] = !{i32 1, !"wchar_size", i32 4}
+// CHECK: [[META1:![0-9]+]] = !{!"{{.*}}clang version {{.*}}"}
+//.
diff --git a/clang/test/CodeGen/aarch64-fmv-dependencies.c b/clang/test/CodeGen/aarch64-fmv-dependencies.c
index f4229a5d233970..9aca1b7a9daf6e 100644
--- a/clang/test/CodeGen/aarch64-fmv-dependencies.c
+++ b/clang/test/CodeGen/aarch64-fmv-dependencies.c
@@ -72,13 +72,10 @@ __attribute__((target_version("ls64"))) int fmv(void) { return 0; }
 // CHECK: define dso_local i32 @fmv._Mlse() #[[lse:[0-9]+]] {
 __attribute__((target_version("lse"))) int fmv(void) { return 0; }
 
-// CHECK: define dso_local i32 @fmv._Mmemtag() #[[ATTR0:[0-9]+]] {
+// CHECK: define dso_local i32 @fmv._Mmemtag() #[[memtag:[0-9]+]] {
 __attribute__((target_version("memtag"))) int fmv(void) { return 0; }
 
-// CHECK: define dso_local i32 @fmv._Mmemtag2() #[[memtag2:[0-9]+]] {
-__attribute__((target_version("memtag2"))) int fmv(void) { return 0; }
-
-// CHECK: define dso_local i32 @fmv._Mmemtag3() #[[memtag2:[0-9]+]] {
+// CHECK: define dso_local i32 @fmv._Mmemtag3() #[[memtag:[0-9]+]] {
 __attribute__((target_version("memtag3"))) int fmv(void) { return 0; }
 
 // CHECK: define dso_local i32 @fmv._Mmops() #[[mops:[0-9]+]] {
@@ -200,7 +197,7 @@ int caller() {
 // CHECK: attributes #[[jscvt]] = { {{.*}} "target-features"="+fp-armv8,+jsconv,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[ls64]] = { {{.*}} "target-features"="+fp-armv8,+ls64,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[lse]] = { {{.*}} "target-features"="+fp-armv8,+lse,+neon,+outline-atomics,+v8a"
-// CHECK: attributes #[[memtag2]] = { {{.*}} "target-features"="+fp-armv8,+mte,+neon,+outline-atomics,+v8a"
+// CHECK: attributes #[[memtag]] = { {{.*}} "target-features"="+fp-armv8,+mte,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[mops]] = { {{.*}} "target-features"="+fp-armv8,+mops,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[pmull]] = { {{.*}} "target-features"="+aes,+fp-armv8,+neon,+outline-atomics,+v8a"
 // CHECK: attributes #[[predres]] = { {{.*}} "target-features"="+fp-armv8,+neon,+outline-atomics,+predres,+v8a"
diff --git a/clang/test/CodeGen/attr-target-clones-aarch64.c b/clang/test/CodeGen/attr-target-clones-aarch64.c
index 292e544139e3ff..c490682e310aff 100644
--- a/clang/test/CodeGen/attr-target-clones-aarch64.c
+++ b/clang/test/CodeGen/attr-target-clones-aarch64.c
@@ -4,10 +4,10 @@
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +mte -target-feature +bti -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK-MTE-BTI
 
 int __attribute__((target_clones("lse+aes", "sve2"))) ftc(void) { return 0; }
-int __attribute__((target_clones("sha2", "sha2+memtag2", " default "))) ftc_def(void) { return 1; }
+int __attribute__((target_clones("sha2", "sha2+memtag", " default "))) ftc_def(void) { return 1; }
 int __attribute__((target_clones("sha2", "default"))) ftc_dup1(void) { return 2; }
 int __attribute__((target_clones("fp", "crc+dotprod"))) ftc_dup2(void) { return 3; }
-int __attribute__((target_clones("memtag2", "bti"))) ftc_dup3(void) { return 4; }
+int __attribute__((target_clones("memtag", "bti"))) ftc_dup3(void) { return 4; }
 int foo() {
   return ftc() + ftc_def() + ftc_dup1() + ftc_dup2() + ftc_dup3();
 }
@@ -90,7 +90,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
-// CHECK-LABEL: define {{[^@]+}}@ftc_def._Mmemtag2Msha2
+// CHECK-LABEL: define {{[^@]+}}@ftc_def._MmemtagMsha2
 // CHECK-SAME: () #[[ATTR3:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 1
@@ -105,7 +105,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-NEXT:    [[TMP3:%.*]] = and i1 true, [[TMP2]]
 // CHECK-NEXT:    br i1 [[TMP3]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE:%.*]]
 // CHECK:       resolver_return:
-// CHECK-NEXT:    ret ptr @ftc_def._Mmemtag2Msha2
+// CHECK-NEXT:    ret ptr @ftc_def._MmemtagMsha2
 // CHECK:       resolver_else:
 // CHECK-NEXT:    [[TMP4:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
 // CHECK-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 4096
@@ -176,7 +176,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
-// CHECK-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag2
+// CHECK-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag
 // CHECK-SAME: () #[[ATTR6:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 4
@@ -206,7 +206,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-NEXT:    [[TMP7:%.*]] = and i1 true, [[TMP6]]
 // CHECK-NEXT:    br i1 [[TMP7]], label [[RESOLVER_RETURN1:%.*]], label [[RESOLVER_ELSE2:%.*]]
 // CHECK:       resolver_return1:
-// CHECK-NEXT:    ret ptr @ftc_dup3._Mmemtag2
+// CHECK-NEXT:    ret ptr @ftc_dup3._Mmemtag
 // CHECK:       resolver_else2:
 // CHECK-NEXT:    ret ptr @ftc_dup3.default
 //
@@ -547,7 +547,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK-MTE-BTI: Function Attrs: noinline nounwind optnone
-// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_def._Mmemtag2Msha2
+// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_def._MmemtagMsha2
 // CHECK-MTE-BTI-SAME: () #[[ATTR2]] {
 // CHECK-MTE-BTI-NEXT:  entry:
 // CHECK-MTE-BTI-NEXT:    ret i32 1
@@ -562,7 +562,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-MTE-BTI-NEXT:    [[TMP3:%.*]] = and i1 true, [[TMP2]]
 // CHECK-MTE-BTI-NEXT:    br i1 [[TMP3]], label [[RESOLVER_RETURN:%.*]], label [[RESOLVER_ELSE:%.*]]
 // CHECK-MTE-BTI:       resolver_return:
-// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_def._Mmemtag2Msha2
+// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_def._MmemtagMsha2
 // CHECK-MTE-BTI:       resolver_else:
 // CHECK-MTE-BTI-NEXT:    [[TMP4:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
 // CHECK-MTE-BTI-NEXT:    [[TMP5:%.*]] = and i64 [[TMP4]], 4096
@@ -633,7 +633,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 //
 //
 // CHECK-MTE-BTI: Function Attrs: noinline nounwind optnone
-// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag2
+// CHECK-MTE-BTI-LABEL: define {{[^@]+}}@ftc_dup3._Mmemtag
 // CHECK-MTE-BTI-SAME: () #[[ATTR5:[0-9]+]] {
 // CHECK-MTE-BTI-NEXT:  entry:
 // CHECK-MTE-BTI-NEXT:    ret i32 4
@@ -663,7 +663,7 @@ inline int __attribute__((target_clones("fp16", "sve2-bitperm+fcma", "default"))
 // CHECK-MTE-BTI-NEXT:    [[TMP7:%.*]] = and i1 true, [[TMP6]]
 // CHECK-MTE-BTI-NEXT:    br i1 [[TMP7]], label [[RESOLVER_RETURN1:%.*]], label [[RESOLVER_ELSE2:%.*]]
 // CHECK-MTE-BTI:       resolver_return1:
-// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_dup3._Mmemtag2
+// CHECK-MTE-BTI-NEXT:    ret ptr @ftc_dup3._Mmemtag
 // CHECK-MTE-BTI:       resolver_else2:
 // CHECK-MTE-BTI-NEXT:    ret ptr @ftc_dup3.default
 //
diff --git a/clang/test/CodeGen/attr-target-version.c b/clang/test/CodeGen/attr-target-version.c
index 22a53c82bfbf9f..0e2c7ad99d81bb 100644
--- a/clang/test/CodeGen/attr-target-version.c
+++ b/clang/test/CodeGen/attr-target-version.c
@@ -34,7 +34,7 @@ inline int __attribute__((target_version("rcpc+frintts"))) fmv_inline(void) { re
 inline int __attribute__((target_version("sve+sve-bf16"))) fmv_inline(void) { return 4; }
 inline int __attribute__((target_version("sve2-aes+sve2-sha3"))) fmv_inline(void) { return 5; }
 inline int __attribute__((target_version("sve2+sve2-pmull128+sve2-bitperm"))) fmv_inline(void) { return 9; }
-inline int __attribute__((target_version("sve2-sm4+memtag2"))) fmv_inline(void) { return 10; }
+inline int __attribute__((target_version("sve2-sm4+memtag"))) fmv_inline(void) { return 10; }
 inline int __attribute__((target_version("memtag3+rcpc3+mops"))) fmv_inline(void) { return 11; }
 inline int __attribute__((target_version("aes+dotprod"))) fmv_inline(void) { return 13; }
 inline int __attribute__((target_version("simd+fp16fml"))) fmv_inline(void) { return 14; }
@@ -500,8 +500,8 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 // CHECK-NEXT:    ret ptr @fmv._McrcMls64
 // CHECK:       resolver_else6:
 // CHECK-NEXT:    [[TMP16:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
-// CHECK-NEXT:    [[TMP17:%.*]] = and i64 [[TMP16]], 8796093022216
-// CHECK-NEXT:    [[TMP18:%.*]] = icmp eq i64 [[TMP17]], 8796093022216
+// CHECK-NEXT:    [[TMP17:%.*]] = and i64 [[TMP16]], 17592186044424
+// CHECK-NEXT:    [[TMP18:%.*]] = icmp eq i64 [[TMP17]], 17592186044424
 // CHECK-NEXT:    [[TMP19:%.*]] = and i1 true, [[TMP18]]
 // CHECK-NEXT:    br i1 [[TMP19]], label [[RESOLVER_RETURN7:%.*]], label [[RESOLVER_ELSE8:%.*]]
 // CHECK:       resolver_return7:
@@ -729,7 +729,7 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
-// CHECK-LABEL: define {{[^@]+}}@fmv_inline._Mmemtag2Msve2-sm4
+// CHECK-LABEL: define {{[^@]+}}@fmv_inline._MmemtagMsve2-sm4
 // CHECK-SAME: () #[[ATTR34:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 10
@@ -751,21 +751,21 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 //
 // CHECK: Function Attrs: noinline nounwind optnone
 // CHECK-LABEL: define {{[^@]+}}@fmv_inline._Mfp16fmlMsimd
-// CHECK-SAME: () #[[ATTR4]] {
+// CHECK-SAME: () #[[ATTR36:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 14
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
 // CHECK-LABEL: define {{[^@]+}}@fmv_inline._MfpMsm4
-// CHECK-SAME: () #[[ATTR36:[0-9]+]] {
+// CHECK-SAME: () #[[ATTR37:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 15
 //
 //
 // CHECK: Function Attrs: noinline nounwind optnone
 // CHECK-LABEL: define {{[^@]+}}@fmv_inline._MlseMrdm
-// CHECK-SAME: () #[[ATTR37:[0-9]+]] {
+// CHECK-SAME: () #[[ATTR38:[0-9]+]] {
 // CHECK-NEXT:  entry:
 // CHECK-NEXT:    ret i32 16
 //
@@ -826,7 +826,7 @@ int caller(void) { return used_def_without_default_decl() + used_decl_without_de
 // CHECK-NEXT:    [[TMP23:%.*]] = and i1 true, [[TMP22]]
 // CHECK-NEXT:    br i1 [[TMP23]], label [[RESOLVER_RETURN9:%.*]], label [[RESOLVER_ELSE10:%.*]]
 // CHECK:       resolver_return9:
-// CHECK-NEXT:    ret ptr @fmv_inline._Mmemtag2Msve2-sm4
+// CHECK-NEXT:    ret ptr @fmv_inline._MmemtagMsve2-sm4
 // CHECK:       resolver_else10:
 // CHECK-NEXT:    [[TMP24:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
 // CHECK-NEXT:    [[TMP25:%.*]] = and i64 [[TMP24]], 1236950581248
diff --git a/clang/test/Sema/attr-target-clones-aarch64.c b/clang/test/Sema/attr-target-clones-aarch64.c
index 2765c06c68fbb8..191ca9ba96506d 100644
--- a/clang/test/Sema/attr-target-clones-aarch64.c
+++ b/clang/test/Sema/attr-target-clones-aarch64.c
@@ -22,7 +22,7 @@ int __attribute__((target_clones("rng", "fp16fml+fp", "default"))) redecl4(void)
 // expected-error@+3 {{'target_clones' attribute does not match previous declaration}}
 // expected-note@-2 {{previous declaration is here}}
 // expected-warning@+1 {{version list contains entries that don't impact code generation}}
-int __attribute__((target_clones("dgh+memtag+rpres", "ebf16+dpb", "default"))) redecl4(void) { return 1; }
+int __attribute__((target_clones("dgh+rpres", "ebf16+dpb", "default"))) redecl4(void) { return 1; }
 
 int __attribute__((target_version("flagm2"))) redef2(void) { return 1; }
 // expected-error@+2 {{multiversioned function redeclarations require identical target attributes}}
diff --git a/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc b/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc
index bb1875fe9f72c8..7af7f42517d1fb 100644
--- a/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc
+++ b/compiler-rt/lib/builtins/cpu_model/AArch64CPUFeatures.inc
@@ -65,7 +65,7 @@ enum CPUFeatures {
   FEAT_SVE_SHA3,
   FEAT_SVE_SM4,
   FEAT_SME,
-  FEAT_MEMTAG,
+  RESERVED_FEAT_MEMTAG, // previously used and now ABI legacy
   FEAT_MEMTAG2,
   FEAT_MEMTAG3,
   FEAT_SB,
diff --git a/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc b/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc
index a9befd7f3e56d7..0f1e9dd85303cf 100644
--- a/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc
+++ b/compiler-rt/lib/builtins/cpu_model/aarch64/fmv/mrs.inc
@@ -45,10 +45,8 @@ static void __init_cpu_features_constructor(unsigned long hwcap,
     setCPUFeature(FEAT_SB);
   if (hwcap & HWCAP_SSBS)
     setCPUFeature(FEAT_SSBS2);
-  if (hwcap2 & HWCAP2_MTE) {
-    setCPUFeature(FEAT_MEMTAG);
+  if (hwcap2 & HWCAP2_MTE)
     setCPUFeature(FEAT_MEMTAG2);
-  }
   if (hwcap2 & HWCAP2_MTE3)
     setCPUFeature(FEAT_MEMTAG3);
   if (hwcap2 & HWCAP2_SVEAES)
diff --git a/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc b/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc
index bb1875fe9f72c8..7af7f42517d1fb 100644
--- a/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc
+++ b/llvm/include/llvm/TargetParser/AArch64CPUFeatures.inc
@@ -65,7 +65,7 @@ enum CPUFeatures {
   FEAT_SVE_SHA3,
   FEAT_SVE_SM4,
   FEAT_SME,
-  FEAT_MEMTAG,
+  RESERVED_FEAT_MEMTAG, // previously used and now ABI legacy
   FEAT_MEMTAG2,
   FEAT_MEMTAG3,
   FEAT_SB,
diff --git a/llvm/lib/Target/AArch64/AArch64FMV.td b/llvm/lib/Target/AArch64/AArch64FMV.td
index c063d3f38ba19c..5674e4dbd56bb7 100644
--- a/llvm/lib/Target/AArch64/AArch64FMV.td
+++ b/llvm/lib/Target/AArch64/AArch64FMV.td
@@ -60,8 +60,7 @@ def : FMVExtension<"i8mm", "FEAT_I8MM", "+i8mm", 270>;
 def : FMVExtension<"jscvt", "FEAT_JSCVT", "+fp-armv8,+neon,+jsconv", 210>;
 def : FMVExtension<"ls64", "FEAT_LS64_ACCDATA", "+ls64", 520>;
 def : FMVExtension<"lse", "FEAT_LSE", "+lse", 80>;
-def : FMVExtension<"memtag", "FEAT_MEMTAG", "", 440>;
-def : FMVExtension<"memtag2", "FEAT_MEMTAG2", "+mte", 450>;
+def : FMVExtension<"memtag", "FEAT_MEMTAG2", "+mte", 440>;
 def : FMVExtension<"memtag3", "FEAT_MEMTAG3", "+mte", 460>;
 def : FMVExtension<"mops", "FEAT_MOPS", "+mops", 650>;
 def : FMVExtension<"pmull", "FEAT_PMULL", "+aes,+fp-armv8,+neon", 160>;

jroelofs · 2024-10-16T17:00:33Z

However these instructions only work at Exception Level 1, so they would be unusable since FMV is a user space facility.

I don't understand this distinction: why is FMV seen as user-space only?

labrinea · 2024-10-17T10:45:34Z

I don't understand this distinction: why is FMV seen as user-space only?

I had to clarify this with @Wilco1 and @DanielKristofKiss. My understanding is that FMV implementations which rely on ifuncs (Linux) only work in address spaces where a dynamic linker can be used. This limitation rules out OS and baremetal environments. However, there are FMV implementations which emulate ifuncs via function pointers (Windows), but the specification must be possible to implement on all platforms, and therefore it is bound by the ifunc limitation.

Wilco1 · 2024-10-17T11:22:47Z

There also isn't any demand to make it work in EL1 - almost all software runs in user space and kernels typically already have their own mechanisms to support different ISA variants. So I wouldn't call it a limitation - it's a high-level feature for average users by design, not kernel developers.

labrinea requested a review from jroelofs October 16, 2024 09:49

llvmbot added clang Clang issues not falling into any other category compiler-rt backend:AArch64 clang:frontend Language frontend issues, e.g. anything involving "Sema" compiler-rt:builtins labels Oct 16, 2024

labrinea requested a review from tmatheson-arm October 16, 2024 09:50

labrinea mentioned this pull request Oct 16, 2024

[FMV][AArch64] Add runtime test for memtag. llvm/llvm-test-suite#173

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[FMV][AArch64] Unify features memtag and memtag2. #112511

[FMV][AArch64] Unify features memtag and memtag2. #112511

labrinea commented Oct 16, 2024

llvmbot commented Oct 16, 2024

llvmbot commented Oct 16, 2024

jroelofs commented Oct 16, 2024

labrinea commented Oct 17, 2024

Wilco1 commented Oct 17, 2024

[FMV][AArch64] Unify features memtag and memtag2. #112511

Are you sure you want to change the base?

[FMV][AArch64] Unify features memtag and memtag2. #112511

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labrinea commented Oct 16, 2024

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llvmbot commented Oct 16, 2024

jroelofs commented Oct 16, 2024

labrinea commented Oct 17, 2024

Wilco1 commented Oct 17, 2024