[RISCV] Support XSfmm C intrinsics

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -13139,6 +13139,7 @@ def err_riscv_attribute_interrupt_requires_extension : Error<
   "RISC-V 'interrupt' attribute '%0' requires extension '%1'">;
 def err_riscv_attribute_interrupt_invalid_combination : Error<
   "RISC-V 'interrupt' attribute contains invalid combination of interrupt types">;
+def err_riscv_builtin_invalid_twiden : Error<"RISC-V XSfmm twiden must be 1, 2 or 4">;
 
 def err_std_source_location_impl_not_found : Error<
   "'std::source_location::__impl' was not found; it must be defined before '__builtin_source_location' is called">;

clang/lib/Sema/SemaRISCV.cpp

@@ -708,8 +708,37 @@ bool SemaRISCV::CheckBuiltinFunctionCall(const TargetInfo &TI,
     return SemaRef.BuiltinConstantArgRange(TheCall, 0, 0, 15) ||
            SemaRef.BuiltinConstantArgMultiple(TheCall, 0, 4);
   }
-  case RISCVVector::BI__builtin_rvv_sf_vtzero_t:
-    return SemaRef.BuiltinConstantArgRange(TheCall, 0, 0, 15);
+  case RISCVVector::BI__builtin_rvv_sf_vtzero_t: {
+    llvm::APSInt Log2SEWResult;
+    llvm::APSInt TWidenResult;
+    if (SemaRef.BuiltinConstantArg(TheCall, 3, Log2SEWResult) ||
+        SemaRef.BuiltinConstantArg(TheCall, 4, TWidenResult))
+      return true;
+
+    int Log2SEW = Log2SEWResult.getSExtValue();
+    int TWiden = TWidenResult.getSExtValue();
+    int TEW = (1 << Log2SEW) * TWiden;
+
+    // 3 <= LogSEW <= 6
+    if (SemaRef.BuiltinConstantArgRange(TheCall, 3, 3, 6))
+      return true;
+
+    // TWiden
+    if (TWiden != 1 && TWiden != 2 && TWiden != 4)
+      return Diag(TheCall->getBeginLoc(),
+                  diag::err_riscv_builtin_invalid_twiden);
+
+    // For TEW = 8, mtd can be 0~15.
+    // For TEW = 16 or 64, mtd can only be 0, 2, 4, 6, 8, 10, 12, 14.
+    // For TEW = 32, mtd can only be 0, 4, 8, 12.
+    if (TEW == 8)
+      return SemaRef.BuiltinConstantArgRange(TheCall, 0, 0, 15);
+    if (TEW == 16 || TEW == 64)
+      return SemaRef.BuiltinConstantArgRange(TheCall, 0, 0, 15) ||
+             SemaRef.BuiltinConstantArgMultiple(TheCall, 0, 2);
+    return SemaRef.BuiltinConstantArgRange(TheCall, 0, 0, 15) ||
+           SemaRef.BuiltinConstantArgMultiple(TheCall, 0, 4);
+  }
   case RISCVVector::BI__builtin_rvv_vget_v: {
     ASTContext::BuiltinVectorTypeInfo ResVecInfo =
         Context.getBuiltinVectorTypeInfo(cast<BuiltinType>(

clang/test/Sema/sifive-xsfmm.c

@@ -19,4 +19,8 @@ void test(vfloat32m8_t arg0, vuint8m8_t arg1) {
   __riscv_sf_mm_e5m2_e4m3(20, arg1, arg1, 1, 2, 3); /* expected-error {{argument value 20 is outside the valid range [0, 15]}} */
   __riscv_sf_mm_u_u(24, arg1, arg1, 1, 2, 3); /* expected-error {{argument value 24 is outside the valid range [0, 15]}} */
   __riscv_sf_vtzero_t_e8w1(18, 0, 0); /* expected-error {{argument value 18 is outside the valid range [0, 15]}} */
+  __riscv_sf_vtzero_t_e16w1(3, 0, 0); /* expected-error {{argument should be a multiple of 2}} */
+  __riscv_sf_vtzero_t_e16w2(3, 0, 0); /* expected-error {{argument should be a multiple of 4}} */
+  __riscv_sf_vtzero_t_e32w1(5, 0, 0); /* expected-error {{argument should be a multiple of 4}} */
+  __riscv_sf_vtzero_t_e32w2(5, 0, 0); /* expected-error {{argument should be a multiple of 2}} */
 }