[WebAssembly] __builtin_wasm_extract_lane_* builtins

[aheejin]

include/clang/Basic/BuiltinsWebAssembly.def

46 ↗

(On Diff #168199)

• I guess the return types should be the same as its element type, because we are translating to not wasm but LLVM IR instructions and extractelement's return type and element type are the same.
• What does I mean in the second argument? The instruction says it is required for constant folding. How is the generated IR different if we use it?

test/CodeGen/builtins-wasm.c

112 ↗

(On Diff #168199)

The same for the return values here.

[craig.topper]

include/clang/Basic/BuiltinsWebAssembly.def

46 ↗

(On Diff #168199)

The I makes Sema ensure it is a Integer Constant Expression.

lib/CodeGen/CGBuiltin.cpp

12433 ↗

(On Diff #168199)

I believe you need to use isIntegerConstantExpr to force clang to really evaluate it as a constant integer. if its a more complicated expression.

[tlively]

• use isIntegerConstantExpr to force constant folding of lanes

[tlively]

include/clang/Basic/BuiltinsWebAssembly.def

46 ↗

(On Diff #168199)

I want these builtins to mimic the underlying wasm instructions as much as possible. I believe end users are more likely to be looking at the WebAssembly spec than the LLVM language reference when using these functions.

[tlively]

• Replace Wi with LLi in signature string
• Remove unnecessary V:128: attribute

cfe/trunk/include/clang/Basic/BuiltinsWebAssembly.def

 BUILTIN(__builtin_wasm_throw, "vUiv*", "r")
 BUILTIN(__builtin_wasm_rethrow, "v", "r")
 
 // Atomic wait and notify.
 BUILTIN(__builtin_wasm_atomic_wait_i32, "ii*iLLi", "n")
 BUILTIN(__builtin_wasm_atomic_wait_i64, "iLLi*LLiLLi", "n")
 BUILTIN(__builtin_wasm_atomic_notify, "Uii*i", "n")
 
+// SIMD builtins
+BUILTIN(__builtin_wasm_extract_lane_s_i8x16, "iV16cIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_u_i8x16, "iV16cIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_s_i16x8, "iV8sIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_u_i16x8, "iV8sIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_i32x4, "iV4iIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_i64x2, "LLiV2LLiIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_f32x4, "fV4fIi", "nc")
+BUILTIN(__builtin_wasm_extract_lane_f64x2, "dV2dIi", "nc")
+
 #undef BUILTIN

cfe/trunk/lib/CodeGen/CGBuiltin.cpp

case WebAssembly::BI__builtin_wasm_atomic_wait_i64: {
     return Builder.CreateCall(Callee, {Addr, Expected, Timeout});
   }
   case WebAssembly::BI__builtin_wasm_atomic_notify: {
     Value *Addr = EmitScalarExpr(E->getArg(0));
     Value *Count = EmitScalarExpr(E->getArg(1));
     Value *Callee = CGM.getIntrinsic(Intrinsic::wasm_atomic_notify);
     return Builder.CreateCall(Callee, {Addr, Count});
   }
+  case WebAssembly::BI__builtin_wasm_extract_lane_s_i8x16:
+  case WebAssembly::BI__builtin_wasm_extract_lane_u_i8x16:
+  case WebAssembly::BI__builtin_wasm_extract_lane_s_i16x8:
+  case WebAssembly::BI__builtin_wasm_extract_lane_u_i16x8:
+  case WebAssembly::BI__builtin_wasm_extract_lane_i32x4:
+  case WebAssembly::BI__builtin_wasm_extract_lane_i64x2:
+  case WebAssembly::BI__builtin_wasm_extract_lane_f32x4:
+  case WebAssembly::BI__builtin_wasm_extract_lane_f64x2: {
+    llvm::APSInt LaneConst;
+    if (!E->getArg(1)->isIntegerConstantExpr(LaneConst, getContext()))
+      llvm_unreachable("Constant arg isn't actually constant?");
+    Value *Vec = EmitScalarExpr(E->getArg(0));
+    Value *Lane = llvm::ConstantInt::get(getLLVMContext(), LaneConst);
+    Value *Extract = Builder.CreateExtractElement(Vec, Lane);
+    switch (BuiltinID) {
+    case WebAssembly::BI__builtin_wasm_extract_lane_s_i8x16:
+    case WebAssembly::BI__builtin_wasm_extract_lane_s_i16x8:
+      return Builder.CreateSExt(Extract, ConvertType(E->getType()));
+    case WebAssembly::BI__builtin_wasm_extract_lane_u_i8x16:
+    case WebAssembly::BI__builtin_wasm_extract_lane_u_i16x8:
+      return Builder.CreateZExt(Extract, ConvertType(E->getType()));
+    case WebAssembly::BI__builtin_wasm_extract_lane_i32x4:
+    case WebAssembly::BI__builtin_wasm_extract_lane_i64x2:
+    case WebAssembly::BI__builtin_wasm_extract_lane_f32x4:
+    case WebAssembly::BI__builtin_wasm_extract_lane_f64x2:
+      return Extract;
+    default:
+      llvm_unreachable("unexpected builtin ID");
+    }
+  }
 
   default:
     return nullptr;
   }
 }
 
 Value *CodeGenFunction::EmitHexagonBuiltinExpr(unsigned BuiltinID,
                                                const CallExpr *E) {

cfe/trunk/test/CodeGen/builtins-wasm.c

-// RUN: %clang_cc1 -triple wasm32-unknown-unknown -O3 -emit-llvm -o - %s \
-// RUN:   | FileCheck %s -check-prefix=WEBASSEMBLY32
-// RUN: %clang_cc1 -triple wasm64-unknown-unknown -O3 -emit-llvm -o - %s \
-// RUN:   | FileCheck %s -check-prefix=WEBASSEMBLY64
+// RUN: %clang_cc1 -triple wasm32-unknown-unknown -fno-lax-vector-conversions \
+// RUN:   -O3 -emit-llvm -o - %s \
+// RUN:   | FileCheck %s -check-prefixes WEBASSEMBLY,WEBASSEMBLY32
+// RUN: %clang_cc1 -triple wasm64-unknown-unknown -fno-lax-vector-conversions \
+// RUN:   -O3 -emit-llvm -o - %s \
+// RUN:   | FileCheck %s -check-prefixes WEBASSEMBLY,WEBASSEMBLY64
+
+// SIMD convenience types
+typedef char i8x16 __attribute((vector_size(16)));
+typedef short i16x8 __attribute((vector_size(16)));
+typedef int i32x4 __attribute((vector_size(16)));
+typedef long long i64x2 __attribute((vector_size(16)));
+typedef unsigned char u8x16 __attribute((vector_size(16)));
+typedef unsigned short u16x8 __attribute((vector_size(16)));
+typedef unsigned int u32x4 __attribute((vector_size(16)));
+typedef unsigned long long u64x2 __attribute((vector_size(16)));
+typedef float f32x4 __attribute((vector_size(16)));
+typedef double f64x2 __attribute((vector_size(16)));
 
 __SIZE_TYPE__ f0(void) {
   return __builtin_wasm_memory_size(0);
   // WEBASSEMBLY32: call {{i.*}} @llvm.wasm.memory.size.i32(i32 0)
   // WEBASSEMBLY64: call {{i.*}} @llvm.wasm.memory.size.i64(i32 0)
 }
 
 __SIZE_TYPE__ f1(__SIZE_TYPE__ delta) {
int f9(long long *addr, long long expected, long long timeout) {
   // WEBASSEMBLY64: call i32 @llvm.wasm.atomic.wait.i64(i64* %{{.*}}, i64 %{{.*}}, i64 %{{.*}})
 }
 
 unsigned int f10(int *addr, int count) {
   return __builtin_wasm_atomic_notify(addr, count);
   // WEBASSEMBLY32: call i32 @llvm.wasm.atomic.notify(i32* %{{.*}}, i32 %{{.*}})
   // WEBASSEMBLY64: call i32 @llvm.wasm.atomic.notify(i32* %{{.*}}, i32 %{{.*}})
 }
+
+int f11(i8x16 v) {
+  return __builtin_wasm_extract_lane_s_i8x16(v, 13);
+  // WEBASSEMBLY: extractelement <16 x i8> %v, i32 13
+  // WEBASSEMBLY-NEXT: sext
+  // WEBASSEMBLY-NEXT: ret
+}
+
+int f12(i8x16 v) {
+  return __builtin_wasm_extract_lane_u_i8x16(v, 13);
+  // WEBASSEMBLY: extractelement <16 x i8> %v, i32 13
+  // WEBASSEMBLY-NEXT: zext
+  // WEBASSEMBLY-NEXT: ret
+}
+
+int f13(i16x8 v) {
+  return __builtin_wasm_extract_lane_s_i16x8(v, 7);
+  // WEBASSEMBLY: extractelement <8 x i16> %v, i32 7
+  // WEBASSEMBLY-NEXT: sext
+  // WEBASSEMBLY-NEXT: ret
+}
+
+int f14(i16x8 v) {
+  return __builtin_wasm_extract_lane_u_i16x8(v, 7);
+  // WEBASSEMBLY: extractelement <8 x i16> %v, i32 7
+  // WEBASSEMBLY-NEXT: zext
+  // WEBASSEMBLY-NEXT: ret
+}
+
+int f15(i32x4 v) {
+  return __builtin_wasm_extract_lane_i32x4(v, 3);
+  // WEBASSEMBLY: extractelement <4 x i32> %v, i32 3
+  // WEBASSEMBLY-NEXT: ret
+}
+
+long long f16(i64x2 v) {
+  return __builtin_wasm_extract_lane_i64x2(v, 1);
+  // WEBASSEMBLY: extractelement <2 x i64> %v, i32 1
+  // WEBASSEMBLY-NEXT: ret
+}
+
+float f17(f32x4 v) {
+  return __builtin_wasm_extract_lane_f32x4(v, 3);
+  // WEBASSEMBLY: extractelement <4 x float> %v, i32 3
+  // WEBASSEMBLY-NEXT: ret
+}
+
+double f18(f64x2 v) {
+  return __builtin_wasm_extract_lane_f64x2(v, 1);
+  // WEBASSEMBLY: extractelement <2 x double> %v, i32 1
+  // WEBASSEMBLY-NEXT: ret
+}