[AVX-512] Add initial support for checking rounding mode arguments of builtins.

The backend can't encode all possible values of the argument and will fail isel. Checking in the frontend presents a friendlier experience to the user.

I started with builtins that can only take _MM_CUR_DIRECTION or _MM_NO_EXC. More builtins coming in the future.

llvm-svn: 282228

1 files changed, 100 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 437c779..7ea34f9 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1642,6 +1642,102 @@ static bool isX86_64Builtin(unsigned BuiltinID) {
   return false;
 }
 
+// Check if the rounding mode is legal.
+bool Sema::CheckX86BuiltinRoundingOrSAE(unsigned BuiltinID, CallExpr *TheCall) {
+  // Indicates if this instruction has rounding control or just SAE.
+  bool HasRC = false;
+
+  unsigned ArgNum = 0;
+  switch (BuiltinID) {
+  default:
+    return false;
+  case X86::BI__builtin_ia32_vcvttsd2si32:
+  case X86::BI__builtin_ia32_vcvttsd2si64:
+  case X86::BI__builtin_ia32_vcvttsd2usi32:
+  case X86::BI__builtin_ia32_vcvttsd2usi64:
+  case X86::BI__builtin_ia32_vcvttss2si32:
+  case X86::BI__builtin_ia32_vcvttss2si64:
+  case X86::BI__builtin_ia32_vcvttss2usi32:
+  case X86::BI__builtin_ia32_vcvttss2usi64:
+    ArgNum = 1;
+    break;
+  case X86::BI__builtin_ia32_cvtps2pd512_mask:
+  case X86::BI__builtin_ia32_cvttpd2dq512_mask:
+  case X86::BI__builtin_ia32_cvttpd2qq512_mask:
+  case X86::BI__builtin_ia32_cvttpd2udq512_mask:
+  case X86::BI__builtin_ia32_cvttpd2uqq512_mask:
+  case X86::BI__builtin_ia32_cvttps2dq512_mask:
+  case X86::BI__builtin_ia32_cvttps2qq512_mask:
+  case X86::BI__builtin_ia32_cvttps2udq512_mask:
+  case X86::BI__builtin_ia32_cvttps2uqq512_mask:
+  case X86::BI__builtin_ia32_exp2pd_mask:
+  case X86::BI__builtin_ia32_exp2ps_mask:
+  case X86::BI__builtin_ia32_getexppd512_mask:
+  case X86::BI__builtin_ia32_getexpps512_mask:
+  case X86::BI__builtin_ia32_rcp28pd_mask:
+  case X86::BI__builtin_ia32_rcp28ps_mask:
+  case X86::BI__builtin_ia32_rsqrt28pd_mask:
+  case X86::BI__builtin_ia32_rsqrt28ps_mask:
+  case X86::BI__builtin_ia32_vcomisd:
+  case X86::BI__builtin_ia32_vcomiss:
+  case X86::BI__builtin_ia32_vcvtph2ps512_mask:
+    ArgNum = 3;
+    break;
+  case X86::BI__builtin_ia32_cmppd512_mask:
+  case X86::BI__builtin_ia32_cmpps512_mask:
+  case X86::BI__builtin_ia32_cmpsd_mask:
+  case X86::BI__builtin_ia32_cmpss_mask:
+  case X86::BI__builtin_ia32_getexpsd128_round_mask:
+  case X86::BI__builtin_ia32_getexpss128_round_mask:
+  case X86::BI__builtin_ia32_rcp28sd_round_mask:
+  case X86::BI__builtin_ia32_rcp28ss_round_mask:
+  case X86::BI__builtin_ia32_reducepd512_mask:
+  case X86::BI__builtin_ia32_reduceps512_mask:
+  case X86::BI__builtin_ia32_rndscalepd_mask:
+  case X86::BI__builtin_ia32_rndscaleps_mask:
+  case X86::BI__builtin_ia32_rsqrt28sd_round_mask:
+  case X86::BI__builtin_ia32_rsqrt28ss_round_mask:
+    ArgNum = 4;
+    break;
+  case X86::BI__builtin_ia32_fixupimmpd512_mask:
+  case X86::BI__builtin_ia32_fixupimmps512_mask:
+  case X86::BI__builtin_ia32_fixupimmsd_mask:
+  case X86::BI__builtin_ia32_fixupimmss_mask:
+  case X86::BI__builtin_ia32_rangepd512_mask:
+  case X86::BI__builtin_ia32_rangeps512_mask:
+  case X86::BI__builtin_ia32_rangesd128_round_mask:
+  case X86::BI__builtin_ia32_rangess128_round_mask:
+  case X86::BI__builtin_ia32_reducesd_mask:
+  case X86::BI__builtin_ia32_reducess_mask:
+  case X86::BI__builtin_ia32_rndscalesd_round_mask:
+  case X86::BI__builtin_ia32_rndscaless_round_mask:
+    ArgNum = 5;
+    break;
+  }
+
+  llvm::APSInt Result;
+
+  // We can't check the value of a dependent argument.
+  Expr *Arg = TheCall->getArg(ArgNum);
+  if (Arg->isTypeDependent() || Arg->isValueDependent())
+    return false;
+
+  // Check constant-ness first.
+  if (SemaBuiltinConstantArg(TheCall, ArgNum, Result))
+    return true;
+
+  // Make sure rounding mode is either ROUND_CUR_DIRECTION or ROUND_NO_EXC bit
+  // is set. If the intrinsic has rounding control(bits 1:0), make sure its only
+  // combined with ROUND_NO_EXC.
+  if (Result == 4/*ROUND_CUR_DIRECTION*/ ||
+      Result == 8/*ROUND_NO_EXC*/ ||
+      (HasRC && Result.getZExtValue() >= 8 && Result.getZExtValue() <= 11))
+    return false;
+
+  return Diag(TheCall->getLocStart(), diag::err_x86_builtin_invalid_rounding)
+    << Arg->getSourceRange();
+}
+
 bool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   if (BuiltinID == X86::BI__builtin_cpu_supports)
     return SemaBuiltinCpuSupports(*this, TheCall);
@@ -1655,6 +1751,10 @@ bool Sema::CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
     return Diag(TheCall->getCallee()->getLocStart(),
                 diag::err_x86_builtin_32_bit_tgt);
 
+  // If the intrinsic has rounding or SAE make sure its valid.
+  if (CheckX86BuiltinRoundingOrSAE(BuiltinID, TheCall))
+    return true;
+
   // For intrinsics which take an immediate value as part of the instruction,
   // range check them here.
   int i = 0, l = 0, u = 0;