MIPS: Added ASSERTs to BranchShort to detect bad use of 'at' register.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 8e4b8ef9737624a6f6d723acf08e752284c8adda..c7f727bef604e1e0eff71ff0987b00b57f5d2c56 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -1557,12 +1557,14 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
         b(offset);
         break;
       case eq:
+        ASSERT(!scratch.is(rs));
         r2 = scratch;
         li(r2, rt);
         offset = shifted_branch_offset(L, false);
         beq(rs, r2, offset);
         break;
       case ne:
+        ASSERT(!scratch.is(rs));
         r2 = scratch;
         li(r2, rt);
         offset = shifted_branch_offset(L, false);
@@ -1574,6 +1576,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           bgtz(rs, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           slt(scratch, r2, rs);
@@ -1590,6 +1593,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           beq(scratch, zero_reg, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           slt(scratch, rs, r2);
@@ -1606,6 +1610,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           bne(scratch, zero_reg, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           slt(scratch, rs, r2);
@@ -1618,6 +1623,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           blez(rs, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           slt(scratch, r2, rs);
@@ -1631,6 +1637,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           bgtz(rs, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           sltu(scratch, r2, rs);
@@ -1647,6 +1654,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           beq(scratch, zero_reg, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           sltu(scratch, rs, r2);
@@ -1663,6 +1671,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           bne(scratch, zero_reg, offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           sltu(scratch, rs, r2);
@@ -1675,6 +1684,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
           offset = shifted_branch_offset(L, false);
           b(offset);
         } else {
+          ASSERT(!scratch.is(rs));
           r2 = scratch;
           li(r2, rt);
           sltu(scratch, r2, rs);