[X86] Make __builtin_ia32_readeflags_u32 and __builtin_ia32_writeeflags_u32 only available on 32-bit targets.

[craig.topper]

Summary

These builtins can't be handled by the backend on 64-bit targets. So error up front instead of throwing an isel error.

Fixes PR37225

[rnk]

Looks good.

cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td

 def note_neon_vector_initializer_non_portable_q : Note<
   "consider using vld1q_%0%1() to initialize a vector from memory, or "
   "vcombine_%0%1(vcreate_%0%1(), vcreate_%0%1()) to initialize from integer "
   "constants">;
 def err_systemz_invalid_tabort_code : Error<
   "invalid transaction abort code">;
 def err_64_bit_builtin_32_bit_tgt : Error<
   "this builtin is only available on 64-bit targets">;
+def err_32_bit_builtin_64_bit_tgt : Error<
+  "this builtin is only available on 32-bit targets">;
 def err_builtin_x64_aarch64_only : Error<
   "this builtin is only available on x86-64 and aarch64 targets">;
 def err_ppc_builtin_only_on_pwr7 : Error<
   "this builtin is only valid on POWER7 or later CPUs">;
 def err_x86_builtin_invalid_rounding : Error<
   "invalid rounding argument">;
 def err_x86_builtin_invalid_scale : Error<
   "scale argument must be 1, 2, 4, or 8">;

cfe/trunk/lib/Sema/SemaChecking.cpp

bool Sema::CheckX86BuiltinGatherScatterScale(unsigned BuiltinID,
 
   if (Result == 1 || Result == 2 || Result == 4 || Result == 8)
     return false;
 
   return Diag(TheCall->getLocStart(), diag::err_x86_builtin_invalid_scale)
     << Arg->getSourceRange();
 }
 
+static bool isX86_32Builtin(unsigned BuiltinID) {
+  // These builtins only work on x86-32 targets.
+  switch (BuiltinID) {
+  case X86::BI__builtin_ia32_readeflags_u32:
+  case X86::BI__builtin_ia32_writeeflags_u32:
+    return true;
+  }
+
+  return false;
+}
+
 bool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   if (BuiltinID == X86::BI__builtin_cpu_supports)
     return SemaBuiltinCpuSupports(*this, TheCall);
 
   if (BuiltinID == X86::BI__builtin_cpu_is)
     return SemaBuiltinCpuIs(*this, TheCall);
 
+  // Check for 32-bit only builtins on a 64-bit target.
+  const llvm::Triple &TT = Context.getTargetInfo().getTriple();
+  if (TT.getArch() != llvm::Triple::x86 && isX86_32Builtin(BuiltinID))
+    return Diag(TheCall->getCallee()->getLocStart(),
+                diag::err_32_bit_builtin_64_bit_tgt);
+
   // If the intrinsic has rounding or SAE make sure its valid.
   if (CheckX86BuiltinRoundingOrSAE(BuiltinID, TheCall))
     return true;
 
   // If the intrinsic has a gather/scatter scale immediate make sure its valid.
   if (CheckX86BuiltinGatherScatterScale(BuiltinID, TheCall))
     return true;
 

cfe/trunk/test/Sema/builtins-x86.c

 typedef long long __m512i __attribute__((__vector_size__(64)));
 typedef float __m512 __attribute__((__vector_size__(64)));
 typedef double __m512d __attribute__((__vector_size__(64)));
 
 typedef unsigned char __mmask8;
 typedef unsigned short __mmask16;
 typedef unsigned int __mmask32;
 
+void call_x86_32_builtins(void) {
+  (void)__builtin_ia32_readeflags_u32();                             // expected-error{{this builtin is only available on 32-bit targets}}
+  (void)__builtin_ia32_writeeflags_u32(4);                           // expected-error{{this builtin is only available on 32-bit targets}}
+}
+
 __m128 test__builtin_ia32_cmpps(__m128 __a, __m128 __b) {
   __builtin_ia32_cmpps(__a, __b, 32); // expected-error {{argument should be a value from 0 to 31}}
 }
 
 __m128d test__builtin_ia32_cmppd(__m128d __a, __m128d __b) {
   __builtin_ia32_cmppd(__a, __b, 32); // expected-error {{argument should be a value from 0 to 31}}
 }