Modify Bigint _mulAdd, _sqrAdd, _estQuotientDigit, and Montgomery _mulMod

runtime/vm/intrinsifier_mips.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 1019 matching lines @@
   __ delay_slot()->addiu(T6, T6, Immediate(Bigint::kBytesPerDigit));
 
   __ Bind(&done);
   // Returning Object::null() is not required, since this method is private.
   __ Ret();
 }
 
 
 void Intrinsifier::Bigint_mulAdd(Assembler* assembler) {
   // Pseudo code:
-  // static void _mulAdd(Uint32List x_digits, int xi,
-  //                     Uint32List m_digits, int i,
-  //                     Uint32List a_digits, int j, int n) {
+  // static int _mulAdd(Uint32List x_digits, int xi,
+  //                    Uint32List m_digits, int i,
+  //                    Uint32List a_digits, int j, int n) {
   //   uint32_t x = x_digits[xi >> 1];  // xi is Smi.
   //   if (x == 0 || n == 0) {
-  //     return;
+  //     return 1;
   //   }
   //   uint32_t* mip = &m_digits[i >> 1];  // i is Smi.
   //   uint32_t* ajp = &a_digits[j >> 1];  // j is Smi.
   //   uint32_t c = 0;
   //   SmiUntag(n);
   //   do {
   //     uint32_t mi = *mip++;
   //     uint32_t aj = *ajp;
   //     uint64_t t = x*mi + aj + c;  // 32-bit * 32-bit -> 64-bit.
   //     *ajp++ = low32(t);
   //     c = high32(t);
   //   } while (--n > 0);
   //   while (c != 0) {
   //     uint64_t t = *ajp + c;
   //     *ajp++ = low32(t);
   //     c = high32(t);  // c == 0 or 1.
   //   }
+  //   return 1;
   // }
 
   Label done;
   // T3 = x, no_op if x == 0
   __ lw(T0, Address(SP, 5 * kWordSize));  // T0 = xi as Smi.
   __ lw(T1, Address(SP, 6 * kWordSize));  // T1 = x_digits.
   __ sll(T0, T0, 1);
   __ addu(T1, T0, T1);
   __ lw(T3, FieldAddress(T1, TypedData::data_offset()));
   __ beq(T3, ZR, &done);
@@ skipping 67 matching lines @@
 
   Label propagate_carry_loop;
   __ Bind(&propagate_carry_loop);
   __ lw(T0, Address(T5, 0));
   __ addiu(T0, T0, Immediate(1));
   __ sw(T0, Address(T5, 0));
   __ beq(T0, ZR, &propagate_carry_loop);
   __ delay_slot()->addiu(T5, T5, Immediate(Bigint::kBytesPerDigit));
 
   __ Bind(&done);
-  // Returning Object::null() is not required, since this method is private.
+  __ addiu(V0, ZR, Immediate(Smi::RawValue(1)));  // One digit processed.
   __ Ret();
 }
 
 
 void Intrinsifier::Bigint_sqrAdd(Assembler* assembler) {
   // Pseudo code:
-  // static void _sqrAdd(Uint32List x_digits, int i,
-  //                     Uint32List a_digits, int used) {
+  // static int _sqrAdd(Uint32List x_digits, int i,
+  //                    Uint32List a_digits, int used) {
   //   uint32_t* xip = &x_digits[i >> 1];  // i is Smi.
   //   uint32_t x = *xip++;
-  //   if (x == 0) return;
+  //   if (x == 0) return 1;
   //   uint32_t* ajp = &a_digits[i];  // j == 2*i, i is Smi.
   //   uint32_t aj = *ajp;
   //   uint64_t t = x*x + aj;
   //   *ajp++ = low32(t);
   //   uint64_t c = high32(t);
   //   int n = ((used - i) >> 1) - 1;  // used and i are Smi.
   //   while (--n >= 0) {
   //     uint32_t xi = *xip++;
   //     uint32_t aj = *ajp;
   //     uint96_t t = 2*x*xi + aj + c;  // 2-bit * 32-bit * 32-bit -> 65-bit.
   //     *ajp++ = low32(t);
   //     c = high64(t);  // 33-bit.
   //   }
   //   uint32_t aj = *ajp;
   //   uint64_t t = aj + c;  // 32-bit + 33-bit -> 34-bit.
   //   *ajp++ = low32(t);
   //   *ajp = high32(t);
+  //   return 1;
   // }
 
   // T4 = xip = &x_digits[i >> 1]
   __ lw(T2, Address(SP, 2 * kWordSize));  // T2 = i as Smi.
   __ lw(T3, Address(SP, 3 * kWordSize));  // T3 = x_digits.
   __ sll(T0, T2, 1);
   __ addu(T3, T0, T3);
   __ addiu(T4, T3, Immediate(TypedData::data_offset() - kHeapObjectTag));
 
   // T3 = x = *xip++, return if x == 0
@@ skipping 83 matching lines @@
   __ addu(T6, T6, T0);
   __ sltu(T1, T6, T0);
   __ addu(T7, T7, T1);
 
   // *ajp = low32(t) = T6
   // *(ajp + 1) = high32(t) = T7
   __ sw(T6, Address(T5, 0));
   __ sw(T7, Address(T5, Bigint::kBytesPerDigit));
 
   __ Bind(&x_zero);
-  // Returning Object::null() is not required, since this method is private.
+  __ addiu(V0, ZR, Immediate(Smi::RawValue(1)));  // One digit processed.
   __ Ret();
 }
 
 
 void Intrinsifier::Bigint_estQuotientDigit(Assembler* assembler) {
   // No unsigned 64-bit / 32-bit divide instruction.
 }
 
 
 void Intrinsifier::Montgomery_mulMod(Assembler* assembler) {
   // Pseudo code:
-  // static void _mulMod(Uint32List args, Uint32List digits, int i) {
-  //   uint32_t rho = args[_RHO];  // _RHO == 0.
+  // static int _mulMod(Uint32List args, Uint32List digits, int i) {
+  //   uint32_t rho = args[_RHO];  // _RHO == 2.
   //   uint32_t d = digits[i >> 1];  // i is Smi.
   //   uint64_t t = rho*d;
-  //   args[_MU] = t mod DIGIT_BASE;  // _MU == 1.
+  //   args[_MU] = t mod DIGIT_BASE;  // _MU == 4.
+  //   return 1;
   // }
 
   // T4 = args
   __ lw(T4, Address(SP, 2 * kWordSize));  // args
 
-  // T3 = rho = args[0]
-  __ lw(T3, FieldAddress(T4, TypedData::data_offset()));
+  // T3 = rho = args[2]
+  __ lw(T3,
+        FieldAddress(T4, TypedData::data_offset() + 2*Bigint::kBytesPerDigit));
 
   // T2 = d = digits[i >> 1]
   __ lw(T0, Address(SP, 0 * kWordSize));  // T0 = i as Smi.
   __ lw(T1, Address(SP, 1 * kWordSize));  // T1 = digits.
   __ sll(T0, T0, 1);
   __ addu(T1, T0, T1);
   __ lw(T2, FieldAddress(T1, TypedData::data_offset()));
 
   // HI:LO = t = rho*d
   __ multu(T2, T3);
 
-  // args[1] = t mod DIGIT_BASE = low32(t)
+  // args[4] = t mod DIGIT_BASE = low32(t)
   __ mflo(T0);
   __ sw(T0,
-        FieldAddress(T4, TypedData::data_offset() + Bigint::kBytesPerDigit));
+        FieldAddress(T4, TypedData::data_offset() + 4*Bigint::kBytesPerDigit));
 
-  // Returning Object::null() is not required, since this method is private.
+  __ addiu(V0, ZR, Immediate(Smi::RawValue(1)));  // One digit processed.
   __ Ret();
 }
 
 
 // Check if the last argument is a double, jump to label 'is_smi' if smi
 // (easy to convert to double), otherwise jump to label 'not_double_smi',
 // Returns the last argument in T0.
 static void TestLastArgumentIsDouble(Assembler* assembler,
                                      Label* is_smi,
                                      Label* not_double_smi) {
@@ skipping 806 matching lines @@
   Isolate* isolate = Isolate::Current();
   __ LoadImmediate(V0, reinterpret_cast<uword>(isolate));
   // Set return value.
   __ Ret();
   __ delay_slot()->lw(V0, Address(V0, Isolate::current_tag_offset()));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS