MIPS: [wasm] Lowering of Int64Shl, Int64Shr, Int64Sar, Int64Add and Int64Sub.

src/compiler/mips/code-generator-mips.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/osr.h"
@@ skipping 812 matching lines @@
       }
       break;
     case kMipsSar:
       if (instr->InputAt(1)->IsRegister()) {
         __ srav(i.OutputRegister(), i.InputRegister(0), i.InputRegister(1));
       } else {
         int32_t imm = i.InputOperand(1).immediate();
         __ sra(i.OutputRegister(), i.InputRegister(0), imm);
       }
       break;
+    case kMipsShlPair: {
+      if (instr->InputAt(2)->IsRegister()) {

[akos.palfi.imgtec, 2016/03/24 12:10:19]

Please move this code into the macro-assembler.

For example, for the register version, you could create a new method, something
like this:
void MacroAssembler::ShlPair(Register dst_low, Register dst_high, Register
src_low, Register src_high,  Register shift);

And for the immediate:
void MacroAssembler::ShlPair(Register dst_low, Register dst_high, Register
src_low, Register src_high, uint32_t shift);

[Marija Antic, 2016/03/24 15:40:34]

Done.

+        Label less_than_32;
+        Label zero_shift;
+        Label word_shift;
+        Label done;
+        __ Branch(&less_than_32, lt, i.InputRegister(2), Operand(32));
+
+        __ Branch(&word_shift, eq, i.InputRegister(2), Operand(32));
+
+        // Shift more than 32
+        __ li(kScratchReg, 0x20);

[balazs.kilvady, 2016/03/24 11:52:46]

Using Operand(32) in the above 2 Branches causes 2 li(at, 32) ops
li(kScratchReg, 0x20) is the 3rd. So I would use one li():

_ li(kScratchReg, 32);
_ Branch(&less_than_32, lt, i.InputRegister(2), Operand(kScratchReg));
_ Branch(&word_shift, eq, i.InputRegister(2), Operand(kScratchReg));

Same for all the copy-pasted variants.

[Marija Antic, 2016/03/24 15:40:34]

Done.

+        __ Subu(kScratchReg, i.InputRegister(2), kScratchReg);
+        __ mov(i.OutputRegister(0), zero_reg);
+        __ sllv(i.OutputRegister(1), i.InputRegister(0), kScratchReg);
+        __ Branch(&done);
+
+        // Word shift
+        __ bind(&word_shift);
+        __ mov(i.OutputRegister(0), zero_reg);
+        __ mov(i.OutputRegister(1), i.InputRegister(0));
+        __ Branch(&done);
+
+        __ bind(&less_than_32);
+
+        // Check if zero shift
+        __ Branch(&zero_shift, eq, i.InputRegister(2), Operand(zero_reg));
+
+        // Shift less than 32
+        __ li(kScratchReg, 0x20);
+        __ Subu(kScratchReg, kScratchReg, i.InputRegister(2));
+        __ sllv(i.OutputRegister(1), i.InputRegister(1), i.InputRegister(2));
+        __ sllv(i.OutputRegister(0), i.InputRegister(0), i.InputRegister(2));
+        __ srlv(kScratchReg, i.InputRegister(0), kScratchReg);
+        __ Or(i.OutputRegister(1), i.OutputRegister(1), kScratchReg);
+        __ Branch(&done);
+
+        // Zero shift
+        __ bind(&zero_shift);
+        __ mov(i.OutputRegister(0), i.InputRegister(0));
+        __ mov(i.OutputRegister(1), i.InputRegister(1));
+        __ bind(&done);
+      } else {
+        int32_t imm = i.InputOperand(2).immediate();
+        if (imm < 32) {
+          if (imm == 0) {
+            __ mov(i.OutputRegister(0), i.InputRegister(0));
+            __ mov(i.OutputRegister(1), i.InputRegister(1));
+          } else {
+            __ sll(i.OutputRegister(1), i.InputRegister(1), imm);
+            __ sll(i.OutputRegister(0), i.InputRegister(0), imm);
+            imm = 32 - imm;
+            __ srl(kScratchReg, i.InputRegister(0), imm);
+            __ Or(i.OutputRegister(1), i.OutputRegister(1), kScratchReg);
+          }
+        } else {
+          if (imm == 32) {
+            __ mov(i.OutputRegister(0), zero_reg);
+            __ mov(i.OutputRegister(1), i.InputRegister(0));
+          } else {
+            imm = imm - 32;
+            __ mov(i.OutputRegister(0), zero_reg);
+            __ sll(i.OutputRegister(1), i.InputRegister(0), imm);
+          }
+        }
+      }
+    } break;
+    case kMipsShrPair: {
+      if (instr->InputAt(2)->IsRegister()) {

[akos.palfi.imgtec, 2016/03/24 12:10:19]

Same here, please move to the macro-asm.

[Marija Antic, 2016/03/24 15:40:34]

Done.

+        Label less_than_32;
+        Label zero_shift;
+        Label word_shift;
+        Label done;
+        __ Branch(&less_than_32, lt, i.InputRegister(2), Operand(32));
+
+        __ Branch(&word_shift, eq, i.InputRegister(2), Operand(32));
+
+        // Shift more than 32
+        __ li(kScratchReg, 0x20);
+        __ Subu(kScratchReg, i.InputRegister(2), kScratchReg);
+        __ mov(i.OutputRegister(1), zero_reg);
+        __ srlv(i.OutputRegister(0), i.InputRegister(1), kScratchReg);
+        __ Branch(&done);
+
+        // Word shift
+        __ bind(&word_shift);
+        __ mov(i.OutputRegister(1), zero_reg);
+        __ mov(i.OutputRegister(0), i.InputRegister(1));
+        __ Branch(&done);
+
+        __ bind(&less_than_32);
+
+        // Check if zero shift
+        __ Branch(&zero_shift, eq, i.InputRegister(2), Operand(zero_reg));
+
+        // Shift less than 32
+        __ li(kScratchReg, 0x20);
+        __ Subu(kScratchReg, kScratchReg, i.InputRegister(2));
+        __ srlv(i.OutputRegister(1), i.InputRegister(1), i.InputRegister(2));
+        __ srlv(i.OutputRegister(0), i.InputRegister(0), i.InputRegister(2));
+        __ sllv(kScratchReg, i.InputRegister(1), kScratchReg);
+        __ Or(i.OutputRegister(0), i.OutputRegister(0), kScratchReg);
+        __ Branch(&done);
+
+        // Zero shift
+        __ bind(&zero_shift);
+        __ mov(i.OutputRegister(0), i.InputRegister(0));
+        __ mov(i.OutputRegister(1), i.InputRegister(1));
+
+        __ bind(&done);
+      } else {
+        int32_t imm = i.InputOperand(2).immediate();
+        if (imm < 32) {
+          if (imm == 0) {
+            __ mov(i.OutputRegister(0), i.InputRegister(0));
+            __ mov(i.OutputRegister(1), i.InputRegister(1));
+          } else {
+            __ srl(i.OutputRegister(1), i.InputRegister(1), imm);
+            __ srl(i.OutputRegister(0), i.InputRegister(0), imm);
+            imm = 32 - imm;
+            __ sll(kScratchReg, i.InputRegister(1), imm);
+            __ Or(i.OutputRegister(0), i.OutputRegister(0), kScratchReg);
+          }
+        } else {
+          if (imm == 32) {
+            __ mov(i.OutputRegister(1), zero_reg);
+            __ mov(i.OutputRegister(0), i.InputRegister(1));
+          } else {
+            imm = imm - 32;
+            __ mov(i.OutputRegister(1), zero_reg);
+            __ srl(i.OutputRegister(0), i.InputRegister(1), imm);
+          }
+        }
+      }
+    } break;
+    case kMipsSarPair: {
+      if (instr->InputAt(2)->IsRegister()) {

[akos.palfi.imgtec, 2016/03/24 12:10:19]

Same here, please move to the macro-asm.

[Marija Antic, 2016/03/24 15:40:34]

Done.

+        Label less_than_32;
+        Label zero_shift;
+        Label word_shift;
+        Label done;
+        __ Branch(&less_than_32, lt, i.InputRegister(2), Operand(32));
+
+        __ Branch(&word_shift, eq, i.InputRegister(2), Operand(32));
+
+        // Shift more than 32
+        __ li(kScratchReg, 0x20);
+        __ li(kScratchReg2, 0x1F);
+        __ Subu(kScratchReg, i.InputRegister(2), kScratchReg);
+        __ srav(i.OutputRegister(1), i.InputRegister(1), kScratchReg2);
+        __ srav(i.OutputRegister(0), i.InputRegister(1), kScratchReg);
+        __ Branch(&done);
+
+        // Word shift
+        __ bind(&word_shift);
+        __ li(kScratchReg2, 0x1F);
+        __ srav(i.OutputRegister(1), i.InputRegister(1), kScratchReg2);
+        __ mov(i.OutputRegister(0), i.InputRegister(1));
+        __ Branch(&done);
+
+        __ bind(&less_than_32);
+        // Check if zero shift
+        __ Branch(&zero_shift, eq, i.InputRegister(2), Operand(zero_reg));
+
+        // Shift less than 32
+        __ li(kScratchReg, 0x20);
+        __ Subu(kScratchReg, kScratchReg, i.InputRegister(2));
+        __ srav(i.OutputRegister(1), i.InputRegister(1), i.InputRegister(2));
+        __ srlv(i.OutputRegister(0), i.InputRegister(0), i.InputRegister(2));
+        __ sllv(kScratchReg, i.InputRegister(1), kScratchReg);
+        __ Or(i.OutputRegister(0), i.OutputRegister(0), kScratchReg);
+        __ Branch(&done);
+
+        // Zero shift
+        __ bind(&zero_shift);
+        __ mov(i.OutputRegister(0), i.InputRegister(0));
+        __ mov(i.OutputRegister(1), i.InputRegister(1));
+
+        __ bind(&done);
+      } else {
+        int32_t imm = i.InputOperand(2).immediate();
+        if (imm < 32) {
+          if (imm == 0) {
+            __ mov(i.OutputRegister(0), i.InputRegister(0));
+            __ mov(i.OutputRegister(1), i.InputRegister(1));
+          } else {
+            __ sra(i.OutputRegister(1), i.InputRegister(1), imm);
+            __ srl(i.OutputRegister(0), i.InputRegister(0), imm);
+            imm = 32 - imm;
+            __ sll(kScratchReg, i.InputRegister(1), imm);
+            __ Or(i.OutputRegister(0), i.OutputRegister(0), kScratchReg);
+          }
+        } else {
+          if (imm == 32) {
+            __ sra(i.OutputRegister(1), i.InputRegister(1), 31);
+            __ mov(i.OutputRegister(0), i.InputRegister(1));
+          } else {
+            imm = imm - 32;
+            __ sra(i.OutputRegister(1), i.InputRegister(1), 31);
+            __ sra(i.OutputRegister(0), i.InputRegister(1), imm);
+          }
+        }
+      }
+    } break;
     case kMipsExt:
       __ Ext(i.OutputRegister(), i.InputRegister(0), i.InputInt8(1),
              i.InputInt8(2));
       break;
     case kMipsIns:
       if (instr->InputAt(1)->IsImmediate() && i.InputInt8(1) == 0) {
         __ Ins(i.OutputRegister(), zero_reg, i.InputInt8(1), i.InputInt8(2));
       } else {
         __ Ins(i.OutputRegister(), i.InputRegister(0), i.InputInt8(1),
                i.InputInt8(2));
@@ skipping 64 matching lines @@
       __ max_s(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
                i.InputDoubleRegister(1));
       break;
     case kMipsMinS:
       __ min_s(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
                i.InputDoubleRegister(1));
       break;
     case kMipsCmpD:
       // Psuedo-instruction used for FP cmp/branch. No opcode emitted here.
       break;
+    case kMipsAddPair: {
+      Label no_overflow;
+      // Add lower word
+      __ Addu(i.OutputRegister(0), i.InputRegister(0), i.InputRegister(2));
+      __ Addu(i.OutputRegister(1), i.InputRegister(1), i.InputRegister(3));
+      // Check for lower word overflow

[akos.palfi.imgtec, 2016/03/24 12:10:19]

Instead of manual overflow checking here, can you use the AddBranchOvf() macro?

[Marija Antic, 2016/03/25 11:17:58]

Simple switching to AddBranchOvf() causes test failures. Investigating this
currently.

On 2016/03/24 12:10:19, akos.palfi.imgtec wrote:

+      __ Sltu(kScratchReg, i.OutputRegister(0), i.InputRegister(0));
+      __ Sltu(kScratchReg2, i.OutputRegister(0), i.InputRegister(2));
+      __ Or(kScratchReg, kScratchReg2, kScratchReg);
+      __ Branch(&no_overflow, eq, kScratchReg, Operand(zero_reg));
+      // Increment higher word if there was overflow
+      __ Addu(i.OutputRegister(1), i.OutputRegister(1), 0x1);
+      __ bind(&no_overflow);
+    } break;
+    case kMipsSubPair: {
+      Label no_overflow;
+      // Subtract lower word
+      __ Subu(i.OutputRegister(0), i.InputRegister(0), i.InputRegister(2));
+      __ Subu(i.OutputRegister(1), i.InputRegister(1), i.InputRegister(3));
+      // Check for lower word underflow

[akos.palfi.imgtec, 2016/03/24 12:10:19]

Same question here with SubBranchOvf().

+      __ Sltu(kScratchReg, i.InputRegister(0), i.OutputRegister(0));
+      __ Branch(&no_overflow, eq, kScratchReg, Operand(zero_reg));
+      // Decrement higher word if there was underflow
+      __ Subu(i.OutputRegister(1), i.OutputRegister(1), 0x1);
+      __ bind(&no_overflow);
+    } break;
     case kMipsAddD:
       // TODO(plind): add special case: combine mult & add.
       __ add_d(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
                i.InputDoubleRegister(1));
       break;
     case kMipsSubD:
       __ sub_d(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
                i.InputDoubleRegister(1));
       break;
     case kMipsMulD:
@@ skipping 938 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8