[X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512 and m[no-]evex512 #132542

phoebewang · 2025-03-22T11:31:08Z

The 256-bit maximum vector register size control was removed from AVX10 whitepaper, ref: https://cdrdv2.intel.com/v1/dl/getContent/784343

Re-target m[no-]avx10.1 to enable AVX10.1 with 512-bit maximum vector register size;
Emit warning for mavx10.x-256, noting AVX10/256 is not supported;
Emit warning for mavx10.x-512, noting to use m[no-]avx10.x instead;
Emit warning for m[no-]evex512, noting AVX10/256 is not supported;

This patch only changes Clang driver behavior. The features avx10.x-256/512 keep unchanged and will be removed in the next release.

The 256-bit maximum vector register size control was removed from AVX10 whitepaper, ref: https://cdrdv2.intel.com/v1/dl/getContent/784343 - Re-target m[no-]avx10.1 to enable AVX10.1 with 512-bit maximum vector register size; - Emit warning for m[no-]avx10.x-256, noting AVX10/256 is not supported; - Emit warning for m[no-]avx10.x-512, noting to use m[no-]avx10.x instead; This patch only changes Clang driver behavior. The features avx10.x-256/512 keep unchanged and will be removed in the next release.

llvmbot · 2025-03-27T03:25:31Z

@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-clang

Author: Phoebe Wang (phoebewang)

Changes

The 256-bit maximum vector register size control was removed from AVX10 whitepaper, ref: https://cdrdv2.intel.com/v1/dl/getContent/784343

Re-target m[no-]avx10.1 to enable AVX10.1 with 512-bit maximum vector register size;
Emit warning for m[no-]avx10.x-256, noting AVX10/256 is not supported;
Emit warning for m[no-]avx10.x-512, noting to use m[no-]avx10.x instead;

This patch only changes Clang driver behavior. The features avx10.x-256/512 keep unchanged and will be removed in the next release.

Full diff: https://github.com/llvm/llvm-project/pull/132542.diff

3 Files Affected:

(modified) clang/include/clang/Driver/Options.td (+3-3)
(modified) clang/lib/Driver/ToolChains/Arch/X86.cpp (+16-3)
(modified) clang/test/Driver/x86-target-features.c (+18-16)

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index fbd5cf632c350..7e380929aeabc 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6406,11 +6406,11 @@ def mavx10_1_256 : Flag<["-"], "mavx10.1-256">, Group<m_x86_AVX10_Features_Group
 def mno_avx10_1_256 : Flag<["-"], "mno-avx10.1-256">, Group<m_x86_AVX10_Features_Group>;
 def mavx10_1_512 : Flag<["-"], "mavx10.1-512">, Group<m_x86_AVX10_Features_Group>;
 def mno_avx10_1_512 : Flag<["-"], "mno-avx10.1-512">, Alias<mno_avx10_1_256>;
-def mavx10_1 : Flag<["-"], "mavx10.1">, Flags<[Unsupported]>;
-def mno_avx10_1 : Flag<["-"], "mno-avx10.1">, Flags<[Unsupported]>;
+def mavx10_1 : Flag<["-"], "mavx10.1">, Group<m_x86_AVX10_Features_Group>;
+def mno_avx10_1 : Flag<["-"], "mno-avx10.1">, Group<m_x86_AVX10_Features_Group>;
 def mavx10_2_256 : Flag<["-"], "mavx10.2-256">, Group<m_x86_AVX10_Features_Group>;
 def mavx10_2_512 : Flag<["-"], "mavx10.2-512">, Group<m_x86_AVX10_Features_Group>;
-def mavx10_2 : Flag<["-"], "mavx10.2">, Alias<mavx10_2_512>;
+def mavx10_2 : Flag<["-"], "mavx10.2">, Group<m_x86_AVX10_Features_Group>;
 def mno_avx10_2 : Flag<["-"], "mno-avx10.2">, Group<m_x86_AVX10_Features_Group>;
 def mavx2 : Flag<["-"], "mavx2">, Group<m_x86_Features_Group>;
 def mno_avx2 : Flag<["-"], "mno-avx2">, Group<m_x86_Features_Group>;
diff --git a/clang/lib/Driver/ToolChains/Arch/X86.cpp b/clang/lib/Driver/ToolChains/Arch/X86.cpp
index 47c2c3e23f9fd..429b041c9c513 100644
--- a/clang/lib/Driver/ToolChains/Arch/X86.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/X86.cpp
@@ -243,10 +243,18 @@ void x86::getX86TargetFeatures(const Driver &D, const llvm::Triple &Triple,
     assert((Version == "1" || Version == "2") && "Invalid AVX10 feature name.");
 
     if (Width == "") {
-      assert(IsNegative && "Only negative options can omit width.");
-      Features.push_back(Args.MakeArgString("-" + Name + "-256"));
+      if (IsNegative)
+        Features.push_back(Args.MakeArgString("-" + Name + "-256"));
+      else
+        Features.push_back(Args.MakeArgString("+" + Name + "-512"));
     } else {
-      assert((Width == "256" || Width == "512") && "Invalid vector length.");
+      if (Width == "512")
+        D.Diag(diag::warn_drv_deprecated_arg) << Name << 1 << Name.drop_back(4);
+      else if (Width == "256")
+        D.Diag(diag::warn_drv_deprecated_custom)
+            << Name << "because AVX10/256 is not supported and will be removed";
+      else
+        assert((Width == "256" || Width == "512") && "Invalid vector length.");
       Features.push_back(Args.MakeArgString((IsNegative ? "-" : "+") + Name));
     }
   }
@@ -275,6 +283,11 @@ void x86::getX86TargetFeatures(const Driver &D, const llvm::Triple &Triple,
       D.Diag(diag::err_drv_unsupported_opt_for_target)
           << A->getSpelling() << Triple.getTriple();
 
+    if (A->getOption().matches(options::OPT_mevex512) ||
+        A->getOption().matches(options::OPT_mno_evex512))
+      D.Diag(diag::warn_drv_deprecated_custom)
+          << Name << "because AVX10/256 is not supported and will be removed";
+
     if (A->getOption().matches(options::OPT_mapx_features_EQ) ||
         A->getOption().matches(options::OPT_mno_apx_features_EQ)) {
 
diff --git a/clang/test/Driver/x86-target-features.c b/clang/test/Driver/x86-target-features.c
index 18361251dcebc..6416a34898e78 100644
--- a/clang/test/Driver/x86-target-features.c
+++ b/clang/test/Driver/x86-target-features.c
@@ -390,15 +390,12 @@
 // AVXVNNIINT16: "-target-feature" "+avxvnniint16"
 // NO-AVXVNNIINT16: "-target-feature" "-avxvnniint16"
 
-// RUN: %clang --target=i386 -mevex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=EVEX512 %s
-// RUN: %clang --target=i386 -mno-evex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-EVEX512 %s
-// EVEX512: "-target-feature" "+evex512"
-// NO-EVEX512: "-target-feature" "-evex512"
-
-// RUN: not %clang --target=i386 -march=i386 -mavx10.1 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=UNSUPPORT-AVX10 %s
-// RUN: not %clang --target=i386 -march=i386 -mno-avx10.1 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=UNSUPPORT-AVX10 %s
-// RUN: %clang --target=i386 -mavx10.1-256 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_1_256 %s
-// RUN: %clang --target=i386 -mavx10.1-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_1_512 %s
+// RUN: %clang --target=i386 -mevex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=EVEX512,WARN-EVEX512 %s
+// RUN: %clang --target=i386 -mno-evex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=NO-EVEX512,WARN-EVEX512 %s
+// RUN: %clang --target=i386 -march=i386 -mavx10.1 %s -### -o %t.o 2>&1 -Werror | FileCheck -check-prefix=AVX10_1_512 %s
+// RUN: %clang --target=i386 -march=i386 -mno-avx10.1 %s -### -o %t.o 2>&1 -Werror | FileCheck -check-prefix=NO-AVX10_1 %s
+// RUN: %clang --target=i386 -mavx10.1-256 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10_1_256,WARN-AVX10-256 %s
+// RUN: %clang --target=i386 -mavx10.1-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10_1_512,WARN-AVX10-512 %s
 // RUN: %clang --target=i386 -mavx10.1-256 -mavx10.1-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_1_512 %s
 // RUN: %clang --target=i386 -mavx10.1-512 -mavx10.1-256 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_1_256 %s
 // RUN: not %clang --target=i386 -march=i386 -mavx10.1-128 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=BAD-AVX10 %s
@@ -406,15 +403,20 @@
 // RUN: not %clang --target=i386 -march=i386 -mavx10.1024-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=BAD-AVX10 %s
 // RUN: %clang --target=i386 -march=i386 -mavx10.1-256 -mavx512f %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10-AVX512 %s
 // RUN: %clang --target=i386 -march=i386 -mavx10.1-256 -mno-avx512f %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10-AVX512 %s
-// RUN: %clang --target=i386 -march=i386 -mavx10.1-256 -mevex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10-EVEX512 %s
-// RUN: %clang --target=i386 -march=i386 -mavx10.1-256 -mno-evex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10-EVEX512 %s
-// RUN: %clang --target=i386 -mavx10.2 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_2_512 %s
-// RUN: %clang --target=i386 -mno-avx10.2 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=NO-AVX10_2 %s
-// RUN: %clang --target=i386 -mavx10.2-256 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_2_256 %s
-// RUN: %clang --target=i386 -mavx10.2-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefix=AVX10_2_512 %s
+// RUN: %clang --target=i386 -march=i386 -mavx10.1-256 -mevex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10-EVEX512,WARN-EVEX512 %s
+// RUN: %clang --target=i386 -march=i386 -mavx10.1-256 -mno-evex512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10-EVEX512,WARN-EVEX512 %s
+// RUN: %clang --target=i386 -mavx10.2 %s -### -o %t.o 2>&1 -Werror | FileCheck -check-prefix=AVX10_2_512 %s
+// RUN: %clang --target=i386 -mno-avx10.2 %s -### -o %t.o 2>&1 -Werror | FileCheck -check-prefix=NO-AVX10_2 %s
+// RUN: %clang --target=i386 -mavx10.2-256 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10_2_256,WARN-AVX10-256 %s
+// RUN: %clang --target=i386 -mavx10.2-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10_2_512,WARN-AVX10-512 %s
 // RUN: %clang --target=i386 -mavx10.2-256 -mavx10.1-512 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10_2_256,AVX10_1_512 %s
 // RUN: %clang --target=i386 -mavx10.2-512 -mavx10.1-256 %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=AVX10_2_512,AVX10_1_256 %s
-// UNSUPPORT-AVX10: error: unsupported option '-m{{.*}}avx10.1' for target 'i386'
+// WARN-EVEX512: warning: argument '{{.*}}evex512' is deprecated, because AVX10/256 is not supported and will be removed [-Wdeprecated]
+// WARN-AVX10-256: warning: argument 'avx10.{{.*}}-256' is deprecated, because AVX10/256 is not supported and will be removed [-Wdeprecated]
+// WARN-AVX10-512: warning: argument 'avx10.{{.*}}-512' is deprecated, use 'avx10.{{.*}}' instead [-Wdeprecated]
+// EVEX512: "-target-feature" "+evex512"
+// NO-EVEX512: "-target-feature" "-evex512"
+// NO-AVX10_1: "-target-feature" "-avx10.1-256"
 // NO-AVX10_2: "-target-feature" "-avx10.2-256"
 // AVX10_2_256: "-target-feature" "+avx10.2-256"
 // AVX10_2_512: "-target-feature" "+avx10.2-512"

phoebewang · 2025-03-31T01:56:35Z

Ping?

RKSimon

LGTM - but we need to add a full explanation to the clang/llvm release notes explaining the avx10 changes/deprecations (and future removal).

phoebewang · 2025-03-31T13:55:06Z

LGTM - but we need to add a full explanation to the clang/llvm release notes explaining the avx10 changes/deprecations (and future removal).

Good reminder! Done.

… and m[no-]evex512 (llvm#132542) The 256-bit maximum vector register size control was removed from AVX10 whitepaper, ref: https://cdrdv2.intel.com/v1/dl/getContent/784343 - Re-target m[no-]avx10.1 to enable AVX10.1 with 512-bit maximum vector register size; - Emit warning for mavx10.x-256, noting AVX10/256 is not supported; - Emit warning for mavx10.x-512, noting to use m[no-]avx10.x instead; - Emit warning for m[no-]evex512, noting AVX10/256 is not supported; This patch only changes Clang driver behavior. The features avx10.x-256/512 keep unchanged and will be removed in the next release.

phoebewang added 2 commits March 22, 2025 19:15

Emit warning for -m[no-]evex512

5e94faa

phoebewang changed the title ~~[X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512~~ [X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512 and m[no-]evex512 Mar 27, 2025

phoebewang marked this pull request as ready for review March 27, 2025 03:24

llvmbot added clang Clang issues not falling into any other category backend:X86 clang:driver 'clang' and 'clang++' user-facing binaries. Not 'clang-cl' labels Mar 27, 2025

phoebewang requested review from RKSimon, e-kud, KanRobert and FreddyLeaf March 27, 2025 03:25

RKSimon approved these changes Mar 31, 2025

View reviewed changes

Add release note

01a8022

RKSimon approved these changes Mar 31, 2025

View reviewed changes

phoebewang merged commit c7572ae into llvm:main Mar 31, 2025
7 of 12 checks passed

phoebewang deleted the AVX10 branch March 31, 2025 14:05

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512 and m[no-]evex512 #132542

[X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512 and m[no-]evex512 #132542

phoebewang commented Mar 22, 2025 •

edited

Loading

Uh oh!

llvmbot commented Mar 27, 2025 •

edited

Loading

Uh oh!

phoebewang commented Mar 31, 2025

Uh oh!

RKSimon left a comment

Uh oh!

phoebewang commented Mar 31, 2025

Uh oh!

Uh oh!

Uh oh!

[X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512 and m[no-]evex512 #132542

[X86][AVX10] Re-target mavx10.1 and emit warning for mavx10.x-256/512 and m[no-]evex512 #132542

Conversation

phoebewang commented Mar 22, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

llvmbot commented Mar 27, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

phoebewang commented Mar 31, 2025

Uh oh!

RKSimon left a comment

Choose a reason for hiding this comment

Uh oh!

phoebewang commented Mar 31, 2025

Uh oh!

Uh oh!

Uh oh!

phoebewang commented Mar 22, 2025 •

edited

Loading

llvmbot commented Mar 27, 2025 •

edited

Loading