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

Make sure 'at' and an immediate operand can't be used together in cases
where 'at' would be overwritten by li.

BUG=
TEST=

Review URL: http://codereview.chromium.org/7791019

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9072 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 8e4b8ef9737624a6f6d723acf08e752284c8adda..c7f727bef604e1e0eff71ff0987b00b57f5d2c56 100644 (file)
--- 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);