[Driver,CodeGen] Report error when enabling 64-bit-only features on non-64-bit arch (#101151)

In front-end, now we detect for `-mapx-features=/-mapxf` and `-muintr`,
which is aligned with GCC

https://gcc.gnu.org/bugzilla/attachment.cgi?id=58698&action=diff

In backend, we just disable these 64-bit-only features silently, so that
there is no error for
`-march=native -m32` on APX-supported arch.

llvm-issue: #94810
GCC thread: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115978

Author: KanRobert

clang/lib/Driver/ToolChains/Arch/X86.cpp

@@ -266,19 +266,29 @@ void x86::getX86TargetFeatures(const Driver &D, const llvm::Triple &Triple,
     }
 
     bool IsNegative = Name.starts_with("no-");
+
+    bool Not64Bit = ArchType != llvm::Triple::x86_64;
+    if (Not64Bit && Name == "uintr")
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << A->getSpelling() << Triple.getTriple();
+
     if (A->getOption().matches(options::OPT_mapx_features_EQ) ||
         A->getOption().matches(options::OPT_mno_apx_features_EQ)) {
 
+      if (Not64Bit && !IsNegative)
+        D.Diag(diag::err_drv_unsupported_opt_for_target)
+            << StringRef(A->getSpelling().str() + "|-mapxf")
+            << Triple.getTriple();
+
       for (StringRef Value : A->getValues()) {
-        if (Value == "egpr" || Value == "push2pop2" || Value == "ppx" ||
-            Value == "ndd" || Value == "ccmp" || Value == "nf" ||
-            Value == "cf" || Value == "zu") {
-          Features.push_back(
-              Args.MakeArgString((IsNegative ? "-" : "+") + Value));
-          continue;
-        }
-        D.Diag(clang::diag::err_drv_unsupported_option_argument)
-            << A->getSpelling() << Value;
+        if (Value != "egpr" && Value != "push2pop2" && Value != "ppx" &&
+            Value != "ndd" && Value != "ccmp" && Value != "nf" &&
+            Value != "cf" && Value != "zu")
+          D.Diag(clang::diag::err_drv_unsupported_option_argument)
+              << A->getSpelling() << Value;
+
+        Features.push_back(
+            Args.MakeArgString((IsNegative ? "-" : "+") + Value));
       }
       continue;
     }

clang/test/Driver/x86-target-features.c

@@ -309,8 +309,8 @@
 // HRESET: "-target-feature" "+hreset"
 // NO-HRESET: "-target-feature" "-hreset"
 
-// RUN: %clang --target=i386 -march=i386 -muintr %s -### 2>&1 | FileCheck -check-prefix=UINTR %s
-// RUN: %clang --target=i386 -march=i386 -mno-uintr %s -### 2>&1 | FileCheck -check-prefix=NO-UINTR %s
+// RUN: %clang --target=x86_64 -muintr %s -### 2>&1 | FileCheck -check-prefix=UINTR %s
+// RUN: %clang --target=x86_64 -mno-uintr %s -### 2>&1 | FileCheck -check-prefix=NO-UINTR %s
 // UINTR: "-target-feature" "+uintr"
 // NO-UINTR: "-target-feature" "-uintr"
 
@@ -409,6 +409,15 @@
 // NONX86-NEXT: warning: argument unused during compilation: '-msse4.2' [-Wunused-command-line-argument]
 // NONX86-NEXT: error: unsupported option '-mno-sgx' for target 'aarch64'
 
+// RUN: not %clang -### --target=i386 -muintr %s 2>&1 | FileCheck --check-prefix=NON-UINTR %s
+// RUN: %clang -### --target=i386 -mno-uintr %s 2>&1 > /dev/null
+// RUN: not %clang -### --target=i386 -mapx-features=ndd %s 2>&1 | FileCheck --check-prefix=NON-APX %s
+// RUN: not %clang -### --target=i386 -mapxf %s 2>&1 | FileCheck --check-prefix=NON-APX %s
+// RUN: %clang -### --target=i386 -mno-apxf %s 2>&1 > /dev/null
+// NON-UINTR:    error: unsupported option '-muintr' for target 'i386'
+// NON-APX:      error: unsupported option '-mapx-features=|-mapxf' for target 'i386'
+// NON-APX-NOT:  error: {{.*}} -mapx-features=
+
 // RUN: %clang --target=i386 -march=i386 -mharden-sls=return %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=SLS-RET,NO-SLS %s
 // RUN: %clang --target=i386 -march=i386 -mharden-sls=indirect-jmp %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=SLS-IJMP,NO-SLS %s
 // RUN: %clang --target=i386 -march=i386 -mharden-sls=none -mharden-sls=all %s -### -o %t.o 2>&1 | FileCheck -check-prefixes=SLS-IJMP,SLS-RET %s

llvm/lib/Target/X86/X86Subtarget.cpp

@@ -279,6 +279,13 @@ void X86Subtarget::initSubtargetFeatures(StringRef CPU, StringRef TuneCPU,
         FullFS += ",+evex512";
   }
 
+  // Disable 64-bit only features in non-64-bit mode.
+  SmallVector<StringRef, 9> FeaturesIn64BitOnly = {
+      "egpr", "push2pop2", "ppx", "ndd", "ccmp", "nf", "cf", "zu", "uintr"};
+  if (FullFS.find("-64bit-mode") != std::string::npos)
+    llvm::for_each(FeaturesIn64BitOnly,
+                   [&](StringRef F) { FullFS += ",-" + F.str(); });
+
   // Parse features string and set the CPU.
   ParseSubtargetFeatures(CPU, TuneCPU, FullFS);
 

llvm/test/CodeGen/X86/apx/i386-ndd.ll

@@ -0,0 +1,15 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=i386-linux-gnu -mattr=+cmov,+ndd < %s | FileCheck %s
+define i32 @test(i1 %cmp, i32 %x, i32 %y) nounwind {
+; CHECK-LABEL: test:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    testb $1, {{[0-9]+}}(%esp)
+; CHECK-NEXT:    leal {{[0-9]+}}(%esp), %eax
+; CHECK-NEXT:    leal {{[0-9]+}}(%esp), %ecx
+; CHECK-NEXT:    cmovnel %eax, %ecx
+; CHECK-NEXT:    movl (%ecx), %eax
+; CHECK-NEXT:    retl
+entry:
+  %cmov = select i1 %cmp, i32 %x, i32 %y
+  ret i32 %cmov
+}