[WebAssembly] Prototype i16x8.q15mulr_sat_s

This saturating, rounding, Q-format multiplication instruction is proposed in
WebAssembly/simd#365.

Differential Revision: https://reviews.llvm.org/D88968

Author: tlively

clang/include/clang/Basic/BuiltinsWebAssembly.def

@@ -114,6 +114,8 @@ TARGET_BUILTIN(__builtin_wasm_max_u_i32x4, "V4UiV4UiV4Ui", "nc", "simd128")
 TARGET_BUILTIN(__builtin_wasm_avgr_u_i8x16, "V16UcV16UcV16Uc", "nc", "simd128")
 TARGET_BUILTIN(__builtin_wasm_avgr_u_i16x8, "V8UsV8UsV8Us", "nc", "simd128")
 
+TARGET_BUILTIN(__builtin_wasm_q15mulr_saturate_s_i8x16, "V8sV8sV8s", "nc", "simd128")
+
 TARGET_BUILTIN(__builtin_wasm_bitselect, "V4iV4iV4iV4i", "nc", "simd128")
 TARGET_BUILTIN(__builtin_wasm_shuffle_v8x16, "V16ScV16ScV16ScIiIiIiIiIiIiIiIiIiIiIiIiIiIiIiIi", "nc", "simd128")
 

clang/lib/CodeGen/CGBuiltin.cpp

@@ -16545,6 +16545,13 @@ Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
                                         ConvertType(E->getType()));
     return Builder.CreateCall(Callee, {LHS, RHS});
   }
+  case WebAssembly::BI__builtin_wasm_q15mulr_saturate_s_i8x16: {
+    Value *LHS = EmitScalarExpr(E->getArg(0));
+    Value *RHS = EmitScalarExpr(E->getArg(1));
+    Function *Callee =
+        CGM.getIntrinsic(Intrinsic::wasm_q15mulr_saturate_signed);
+    return Builder.CreateCall(Callee, {LHS, RHS});
+  }
   case WebAssembly::BI__builtin_wasm_bitselect: {
     Value *V1 = EmitScalarExpr(E->getArg(0));
     Value *V2 = EmitScalarExpr(E->getArg(1));

clang/test/CodeGen/builtins-wasm.c

@@ -462,6 +462,13 @@ u16x8 avgr_u_i16x8(u16x8 x, u16x8 y) {
   // WEBASSEMBLY-NEXT: ret
 }
 
+i16x8 q15mulr_saturate_s_i16x8(i16x8 x, i16x8 y) {
+  return __builtin_wasm_q15mulr_saturate_s_i8x16(x, y);
+  // WEBASSEMBLY: call <8 x i16> @llvm.wasm.q15mulr.saturate.signed(
+  // WEBASSEMBLY-SAME: <8 x i16> %x, <8 x i16> %y)
+  // WEBASSEMBLY-NEXT: ret
+}
+
 i32x4 dot_i16x8_s(i16x8 x, i16x8 y) {
   return __builtin_wasm_dot_s_i32x4_i16x8(x, y);
   // WEBASSEMBLY: call <4 x i32> @llvm.wasm.dot(<8 x i16> %x, <8 x i16> %y)

llvm/include/llvm/IR/IntrinsicsWebAssembly.td

@@ -159,6 +159,10 @@ def int_wasm_narrow_unsigned :
   Intrinsic<[llvm_anyvector_ty],
             [llvm_anyvector_ty, LLVMMatchType<1>],
             [IntrNoMem, IntrSpeculatable]>;
+def int_wasm_q15mulr_saturate_signed :
+  Intrinsic<[llvm_v8i16_ty],
+            [llvm_v8i16_ty, llvm_v8i16_ty],
+            [IntrNoMem, IntrSpeculatable]>;
 
 // TODO: Replace these intrinsics with normal ISel patterns
 def int_wasm_pmin :

llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td

@@ -1093,3 +1093,11 @@ multiclass SIMDQFM<ValueType vec_t, string vec, bits<32> simdopA,
 
 defm "" : SIMDQFM<v4f32, "f32x4", 180, 212>;
 defm "" : SIMDQFM<v2f64, "f64x2", 254, 255>;
+
+//===----------------------------------------------------------------------===//
+// Saturating Rounding Q-Format Multiplication
+//===----------------------------------------------------------------------===//
+
+defm Q15MULR_SAT_S :
+  SIMDBinary<v8i16, "i16x8", int_wasm_q15mulr_saturate_signed, "q15mulr_sat_s",
+             156>;

llvm/test/CodeGen/WebAssembly/simd-intrinsics.ll

@@ -228,6 +228,17 @@ define <8 x i16> @avgr_u_v8i16(<8 x i16> %x, <8 x i16> %y) {
   ret <8 x i16> %a
 }
 
+; CHECK-LABEL: q15mulr_sat_s_v8i16:
+; SIMD128-NEXT: .functype q15mulr_sat_s_v8i16 (v128, v128) -> (v128){{$}}
+; SIMD128-NEXT: i16x8.q15mulr_sat_s $push[[R:[0-9]+]]=, $0, $1{{$}}
+; SIMD128-NEXT: return $pop[[R]]{{$}}
+declare <8 x i16> @llvm.wasm.q15mulr.saturate.signed(<8 x i16>, <8 x i16>)
+define <8 x i16> @q15mulr_sat_s_v8i16(<8 x i16> %x, <8 x i16> %y) {
+  %a = call <8 x i16> @llvm.wasm.q15mulr.saturate.signed(<8 x i16> %x,
+                                                         <8 x i16> %y)
+  ret <8 x i16> %a
+}
+
 ; CHECK-LABEL: any_v8i16:
 ; SIMD128-NEXT: .functype any_v8i16 (v128) -> (i32){{$}}
 ; SIMD128-NEXT: i16x8.any_true $push[[R:[0-9]+]]=, $0{{$}}

llvm/test/MC/WebAssembly/simd-encodings.s

@@ -421,6 +421,9 @@ main:
     # CHECK: i16x8.avgr_u # encoding: [0xfd,0x9b,0x01]
     i16x8.avgr_u
 
+    # CHECK: i16x8.q15mulr_sat_s # encoding: [0xfd,0x9c,0x01]
+    i16x8.q15mulr_sat_s
+
     # CHECK: i32x4.abs # encoding: [0xfd,0xa0,0x01]
     i32x4.abs