[Liftoff] Implement f32.neg and f64.neg

This adds support for f32.neg and f64.neg. Note that this cannot be
computed as "0 - src", as this would not turn 0 into -0. Instead, we
need to explicitly flip the sign bit.

R=ahaas@chromium.org

Bug: v8:6600
Change-Id: I3cbcfa156c5d2a727e0e2da279369bf055f0d657
Reviewed-on: https://chromium-review.googlesource.com/937202Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51601}

src/wasm/baseline/arm/liftoff-assembler-arm.h

@@ -113,6 +113,10 @@ void LiftoffAssembler::FillI64Half(Register, uint32_t half_index) {
                                      DoubleRegister rhs) {                   \
     BAILOUT("fp binop");                                                     \
   }
+#define UNIMPLEMENTED_FP_UNOP(name)                                            \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister src) { \
+    BAILOUT("fp unop");                                                        \
+  }
 #define UNIMPLEMENTED_SHIFTOP(name)                                            \
   void LiftoffAssembler::emit_##name(Register dst, Register lhs, Register rhs, \
                                      LiftoffRegList pinned) {                  \
@@ -135,13 +139,16 @@ UNIMPLEMENTED_GP_BINOP(ptrsize_add)
 UNIMPLEMENTED_FP_BINOP(f32_add)
 UNIMPLEMENTED_FP_BINOP(f32_sub)
 UNIMPLEMENTED_FP_BINOP(f32_mul)
+UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_BINOP(f64_add)
 UNIMPLEMENTED_FP_BINOP(f64_sub)
 UNIMPLEMENTED_FP_BINOP(f64_mul)
+UNIMPLEMENTED_FP_UNOP(f64_neg)
 
 #undef UNIMPLEMENTED_GP_BINOP
 #undef UNIMPLEMENTED_GP_UNOP
 #undef UNIMPLEMENTED_FP_BINOP
+#undef UNIMPLEMENTED_FP_UNOP
 #undef UNIMPLEMENTED_SHIFTOP
 
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }

src/wasm/baseline/arm64/liftoff-assembler-arm64.h

@@ -113,6 +113,10 @@ void LiftoffAssembler::FillI64Half(Register, uint32_t half_index) {
                                      DoubleRegister rhs) {                   \
     BAILOUT("fp binop");                                                     \
   }
+#define UNIMPLEMENTED_FP_UNOP(name)                                            \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister src) { \
+    BAILOUT("fp unop");                                                        \
+  }
 #define UNIMPLEMENTED_SHIFTOP(name)                                            \
   void LiftoffAssembler::emit_##name(Register dst, Register lhs, Register rhs, \
                                      LiftoffRegList pinned) {                  \
@@ -135,13 +139,16 @@ UNIMPLEMENTED_GP_BINOP(ptrsize_add)
 UNIMPLEMENTED_FP_BINOP(f32_add)
 UNIMPLEMENTED_FP_BINOP(f32_sub)
 UNIMPLEMENTED_FP_BINOP(f32_mul)
+UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_BINOP(f64_add)
 UNIMPLEMENTED_FP_BINOP(f64_sub)
 UNIMPLEMENTED_FP_BINOP(f64_mul)
+UNIMPLEMENTED_FP_UNOP(f64_neg)
 
 #undef UNIMPLEMENTED_GP_BINOP
 #undef UNIMPLEMENTED_GP_UNOP
 #undef UNIMPLEMENTED_FP_BINOP
+#undef UNIMPLEMENTED_FP_UNOP
 #undef UNIMPLEMENTED_SHIFTOP
 
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }

src/wasm/baseline/ia32/liftoff-assembler-ia32.h

@@ -587,6 +587,17 @@ void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
   }
 }
 
+void LiftoffAssembler::emit_f32_neg(DoubleRegister dst, DoubleRegister src) {
+  static constexpr uint32_t kSignBit = uint32_t{1} << 31;
+  if (dst == src) {
+    TurboAssembler::Move(kScratchDoubleReg, kSignBit);
+    Xorps(dst, kScratchDoubleReg);
+  } else {
+    TurboAssembler::Move(dst, kSignBit);
+    Xorps(dst, src);
+  }
+}
+
 void LiftoffAssembler::emit_f64_add(DoubleRegister dst, DoubleRegister lhs,
                                     DoubleRegister rhs) {
   if (CpuFeatures::IsSupported(AVX)) {
@@ -628,6 +639,17 @@ void LiftoffAssembler::emit_f64_mul(DoubleRegister dst, DoubleRegister lhs,
   }
 }
 
+void LiftoffAssembler::emit_f64_neg(DoubleRegister dst, DoubleRegister src) {
+  static constexpr uint64_t kSignBit = uint64_t{1} << 63;
+  if (dst == src) {
+    TurboAssembler::Move(kScratchDoubleReg, kSignBit);
+    Xorpd(dst, kScratchDoubleReg);
+  } else {
+    TurboAssembler::Move(dst, kSignBit);
+    Xorpd(dst, src);
+  }
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { jmp(label); }
 
 void LiftoffAssembler::emit_cond_jump(Condition cond, Label* label,

src/wasm/baseline/liftoff-assembler.h

@@ -373,12 +373,17 @@ class LiftoffAssembler : public TurboAssembler {
 
   inline void emit_ptrsize_add(Register dst, Register lhs, Register rhs);
 
+  // f32 binops.
   inline void emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
   inline void emit_f32_sub(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
   inline void emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
+  // f32 unops.
+  inline void emit_f32_neg(DoubleRegister dst, DoubleRegister src);
+
+  // f64 binops.
   inline void emit_f64_add(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
   inline void emit_f64_sub(DoubleRegister dst, DoubleRegister lhs,
@@ -386,6 +391,9 @@ class LiftoffAssembler : public TurboAssembler {
   inline void emit_f64_mul(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
 
+  // f64 unops.
+  inline void emit_f64_neg(DoubleRegister dst, DoubleRegister src);
+
   inline void emit_jump(Label*);
   inline void emit_cond_jump(Condition, Label*, ValueType value, Register lhs,
                              Register rhs = no_reg);

src/wasm/baseline/liftoff-compiler.cc

@@ -542,6 +542,12 @@ class LiftoffCompiler {
       __ emit_##fn(dst.gp(), src.gp());                                \
     });                                                                \
     break;
+#define CASE_FLOAT_UNOP(opcode, type, fn)                                 \
+  case WasmOpcode::kExpr##opcode:                                         \
+    EmitUnOp<kWasm##type>([=](LiftoffRegister dst, LiftoffRegister src) { \
+      __ emit_##fn(dst.fp(), src.fp());                                   \
+    });                                                                   \
+    break;
     switch (opcode) {
       CASE_I32_UNOP(I32Clz, i32_clz)
       CASE_I32_UNOP(I32Ctz, i32_ctz)
@@ -554,10 +560,13 @@ class LiftoffCompiler {
           __ emit_i32_set_cond(kEqual, dst.gp(), src.gp());
         });
         break;
+        CASE_FLOAT_UNOP(F32Neg, F32, f32_neg)
+        CASE_FLOAT_UNOP(F64Neg, F64, f64_neg)
       default:
         return unsupported(decoder, WasmOpcodes::OpcodeName(opcode));
     }
 #undef CASE_I32_UNOP
+#undef CASE_FLOAT_UNOP
   }
 
   template <ValueType type, typename EmitFn>

src/wasm/baseline/mips/liftoff-assembler-mips.h

@@ -317,15 +317,22 @@ I32_SHIFTOP(shr, srlv)
                                      DoubleRegister rhs) {                   \
     instruction(dst, lhs, rhs);                                              \
   }
+#define UNIMPLEMENTED_FP_UNOP(name)                                            \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister src) { \
+    BAILOUT("fp unop");                                                        \
+  }
 
 FP_BINOP(f32_add, add_s)
 FP_BINOP(f32_sub, sub_s)
 FP_BINOP(f32_mul, mul_s)
+UNIMPLEMENTED_FP_UNOP(f32_neg)
 FP_BINOP(f64_add, add_d)
 FP_BINOP(f64_sub, sub_d)
 FP_BINOP(f64_mul, mul_d)
+UNIMPLEMENTED_FP_UNOP(f64_neg)
 
 #undef FP_BINOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_jump(Label* label) {
   TurboAssembler::Branch(label);

src/wasm/baseline/mips64/liftoff-assembler-mips64.h

@@ -276,15 +276,22 @@ I32_SHIFTOP(shr, srlv)
                                      DoubleRegister rhs) {                   \
     instruction(dst, lhs, rhs);                                              \
   }
+#define UNIMPLEMENTED_FP_UNOP(name)                                            \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister src) { \
+    BAILOUT("fp unop");                                                        \
+  }
 
 FP_BINOP(f32_add, add_s)
 FP_BINOP(f32_sub, sub_s)
 FP_BINOP(f32_mul, mul_s)
+UNIMPLEMENTED_FP_UNOP(f32_neg)
 FP_BINOP(f64_add, add_d)
 FP_BINOP(f64_sub, sub_d)
 FP_BINOP(f64_mul, mul_d)
+UNIMPLEMENTED_FP_UNOP(f64_neg)
 
 #undef FP_BINOP
+#undef UNIMPLEMENTED_FP_BINOP
 
 void LiftoffAssembler::emit_jump(Label* label) {
   TurboAssembler::Branch(label);
@@ -354,7 +361,7 @@ void LiftoffAssembler::PopRegisters(LiftoffRegList regs) {
 }
 
 void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
-  DCHECK_LT(num_stack_slots, (1 << 16) / kPointerSize);
+  DCHECK_LT(num_stack_slots, (1 << 16) / kPointerSize);  // 16 bit immediate
   TurboAssembler::DropAndRet(static_cast<int>(num_stack_slots * kPointerSize));
 }
 

src/wasm/baseline/ppc/liftoff-assembler-ppc.h

@@ -113,6 +113,10 @@ void LiftoffAssembler::FillI64Half(Register, uint32_t half_index) {
                                      DoubleRegister rhs) {                   \
     BAILOUT("fp binop");                                                     \
   }
+#define UNIMPLEMENTED_FP_UNOP(name)                                            \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister src) { \
+    BAILOUT("fp unop");                                                        \
+  }
 #define UNIMPLEMENTED_SHIFTOP(name)                                            \
   void LiftoffAssembler::emit_##name(Register dst, Register lhs, Register rhs, \
                                      LiftoffRegList pinned) {                  \
@@ -135,13 +139,16 @@ UNIMPLEMENTED_GP_BINOP(ptrsize_add)
 UNIMPLEMENTED_FP_BINOP(f32_add)
 UNIMPLEMENTED_FP_BINOP(f32_sub)
 UNIMPLEMENTED_FP_BINOP(f32_mul)
+UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_BINOP(f64_add)
 UNIMPLEMENTED_FP_BINOP(f64_sub)
 UNIMPLEMENTED_FP_BINOP(f64_mul)
+UNIMPLEMENTED_FP_UNOP(f64_neg)
 
 #undef UNIMPLEMENTED_GP_BINOP
 #undef UNIMPLEMENTED_GP_UNOP
 #undef UNIMPLEMENTED_FP_BINOP
+#undef UNIMPLEMENTED_FP_UNOP
 #undef UNIMPLEMENTED_SHIFTOP
 
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }

src/wasm/baseline/s390/liftoff-assembler-s390.h

@@ -113,6 +113,10 @@ void LiftoffAssembler::FillI64Half(Register, uint32_t half_index) {
                                      DoubleRegister rhs) {                   \
     BAILOUT("fp binop");                                                     \
   }
+#define UNIMPLEMENTED_FP_UNOP(name)                                            \
+  void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister src) { \
+    BAILOUT("fp unop");                                                        \
+  }
 #define UNIMPLEMENTED_SHIFTOP(name)                                            \
   void LiftoffAssembler::emit_##name(Register dst, Register lhs, Register rhs, \
                                      LiftoffRegList pinned) {                  \
@@ -135,13 +139,16 @@ UNIMPLEMENTED_GP_BINOP(ptrsize_add)
 UNIMPLEMENTED_FP_BINOP(f32_add)
 UNIMPLEMENTED_FP_BINOP(f32_sub)
 UNIMPLEMENTED_FP_BINOP(f32_mul)
+UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_BINOP(f64_add)
 UNIMPLEMENTED_FP_BINOP(f64_sub)
 UNIMPLEMENTED_FP_BINOP(f64_mul)
+UNIMPLEMENTED_FP_UNOP(f64_neg)
 
 #undef UNIMPLEMENTED_GP_BINOP
 #undef UNIMPLEMENTED_GP_UNOP
 #undef UNIMPLEMENTED_FP_BINOP
+#undef UNIMPLEMENTED_FP_UNOP
 #undef UNIMPLEMENTED_SHIFTOP
 
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }

src/wasm/baseline/x64/liftoff-assembler-x64.h

@@ -520,6 +520,17 @@ void LiftoffAssembler::emit_f32_mul(DoubleRegister dst, DoubleRegister lhs,
   }
 }
 
+void LiftoffAssembler::emit_f32_neg(DoubleRegister dst, DoubleRegister src) {
+  static constexpr uint32_t kSignBit = uint32_t{1} << 31;
+  if (dst == src) {
+    TurboAssembler::Move(kScratchDoubleReg, kSignBit);
+    Xorps(dst, kScratchDoubleReg);
+  } else {
+    TurboAssembler::Move(dst, kSignBit);
+    Xorps(dst, src);
+  }
+}
+
 void LiftoffAssembler::emit_f64_add(DoubleRegister dst, DoubleRegister lhs,
                                     DoubleRegister rhs) {
   if (CpuFeatures::IsSupported(AVX)) {
@@ -561,6 +572,17 @@ void LiftoffAssembler::emit_f64_mul(DoubleRegister dst, DoubleRegister lhs,
   }
 }
 
+void LiftoffAssembler::emit_f64_neg(DoubleRegister dst, DoubleRegister src) {
+  static constexpr uint64_t kSignBit = uint64_t{1} << 63;
+  if (dst == src) {
+    TurboAssembler::Move(kScratchDoubleReg, kSignBit);
+    Xorpd(dst, kScratchDoubleReg);
+  } else {
+    TurboAssembler::Move(dst, kSignBit);
+    Xorpd(dst, src);
+  }
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { jmp(label); }
 
 void LiftoffAssembler::emit_cond_jump(Condition cond, Label* label,