MIPS64: Fix bugs in branches for unsigned conditions.

TEST=cctest/test-branch-combine
BUG=

Review URL: https://codereview.chromium.org/1017733002

Cr-Commit-Position: refs/heads/master@{#27245}

src/mips64/macro-assembler-mips64.cc

@@ -2122,7 +2122,7 @@ void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
       // Unsigned comparison.
       case Ugreater:
         if (r2.is(zero_reg)) {
-          bgtz(rs, offset);
+          bne(rs, zero_reg, offset);
         } else {
           sltu(scratch, r2, rs);
           bne(scratch, zero_reg, offset);
@@ -2130,7 +2130,7 @@ void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
         break;
       case Ugreater_equal:
         if (r2.is(zero_reg)) {
-          bgez(rs, offset);
+          b(offset);
         } else {
           sltu(scratch, rs, r2);
           beq(scratch, zero_reg, offset);
@@ -2147,7 +2147,7 @@ void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
         break;
       case Uless_equal:
         if (r2.is(zero_reg)) {
-          b(offset);
+          beq(rs, zero_reg, offset);
         } else {
           sltu(scratch, r2, rs);
           beq(scratch, zero_reg, offset);
@@ -2237,7 +2237,7 @@ void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
       // Unsigned comparison.
       case Ugreater:
         if (rt.imm64_ == 0) {
-          bgtz(rs, offset);
+          bne(rs, zero_reg, offset);
         } else {
           r2 = scratch;
           li(r2, rt);
@@ -2247,7 +2247,7 @@ void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
         break;
       case Ugreater_equal:
         if (rt.imm64_ == 0) {
-          bgez(rs, offset);
+          b(offset);
         } else if (is_int16(rt.imm64_)) {
           sltiu(scratch, rs, rt.imm64_);
           beq(scratch, zero_reg, offset);
@@ -2274,7 +2274,7 @@ void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
         break;
       case Uless_equal:
         if (rt.imm64_ == 0) {
-          b(offset);
+          beq(rs, zero_reg, offset);
         } else {
           r2 = scratch;
           li(r2, rt);
@@ -2376,7 +2376,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
       case Ugreater:
         if (r2.is(zero_reg)) {
           offset = shifted_branch_offset(L, false);
-           bgtz(rs, offset);
+          bne(rs, zero_reg, offset);
         } else {
           sltu(scratch, r2, rs);
           offset = shifted_branch_offset(L, false);
@@ -2386,7 +2386,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
       case Ugreater_equal:
         if (r2.is(zero_reg)) {
           offset = shifted_branch_offset(L, false);
-          bgez(rs, offset);
+          b(offset);
         } else {
           sltu(scratch, rs, r2);
           offset = shifted_branch_offset(L, false);
@@ -2406,7 +2406,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
       case Uless_equal:
         if (r2.is(zero_reg)) {
           offset = shifted_branch_offset(L, false);
-          b(offset);
+          beq(rs, zero_reg, offset);
         } else {
           sltu(scratch, r2, rs);
           offset = shifted_branch_offset(L, false);
@@ -2528,7 +2528,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
       case Ugreater_equal:
         if (rt.imm64_ == 0) {
           offset = shifted_branch_offset(L, false);
-          bgez(rs, offset);
+          b(offset);
         } else if (is_int16(rt.imm64_)) {
           sltiu(scratch, rs, rt.imm64_);
           offset = shifted_branch_offset(L, false);

src/mips64/simulator-mips64.cc

@@ -2976,7 +2976,7 @@ void Simulator::DecodeTypeImmediate(Instruction* instr) {
       alu_out = (rs < se_imm16) ? 1 : 0;
       break;
     case SLTIU:
-      alu_out = (rs_u < static_cast<uint32_t>(se_imm16)) ? 1 : 0;
+      alu_out = (rs_u < static_cast<uint64_t>(se_imm16)) ? 1 : 0;
       break;
     case ANDI:
         alu_out = rs & oe_imm16;