[tor-commits] [tor-browser/esr24] Bug 1012694 - IonMonkey (ARM): Use the second scratch register to avoid clobbering the scratch register. r=dougc, a=abillings

[mikeperry at torproject.org]

commit 8acbe105e17e37d23712925261926f04363f7b22
Author: Douglas Crosher <dtc-moz at scieneer.com>
Date:   Tue Jun 17 11:47:45 2014 +1000

    Bug 1012694 - IonMonkey (ARM): Use the second scratch register to avoid clobbering the scratch register. r=dougc, a=abillings
---
 js/src/jit/arm/MacroAssembler-arm.h |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/js/src/jit/arm/MacroAssembler-arm.h b/js/src/jit/arm/MacroAssembler-arm.h
index 04d68af..7bc0da0 100644
--- a/js/src/jit/arm/MacroAssembler-arm.h
+++ b/js/src/jit/arm/MacroAssembler-arm.h
@@ -763,8 +763,9 @@ class MacroAssemblerARMCompat : public MacroAssemblerARM
         if (lhs.getTag() == Operand::OP2) {
             branch32(cond, lhs.toReg(), rhs, label);
         } else {
-            ma_ldr(lhs, ScratchRegister);
-            branch32(cond, ScratchRegister, rhs, label);
+            // branch32 will use ScratchRegister.
+            ma_ldr(lhs, secondScratchReg_);
+            branch32(cond, secondScratchReg_, rhs, label);
         }
     }
     void branch32(Condition cond, const Address &lhs, Register rhs, Label *label) {
@@ -772,8 +773,9 @@ class MacroAssemblerARMCompat : public MacroAssemblerARM
         branch32(cond, ScratchRegister, rhs, label);
     }
     void branch32(Condition cond, const Address &lhs, Imm32 rhs, Label *label) {
-        load32(lhs, ScratchRegister);
-        branch32(cond, ScratchRegister, rhs, label);
+        // branch32 will use ScratchRegister.
+        load32(lhs, secondScratchReg_);
+        branch32(cond, secondScratchReg_, rhs, label);
     }
     void branchPtr(Condition cond, const Address &lhs, Register rhs, Label *label) {
         branch32(cond, lhs, rhs, label);
@@ -856,8 +858,9 @@ class MacroAssemblerARMCompat : public MacroAssemblerARM
         ma_b(label, cond);
     }
     void branchTest32(Condition cond, const Address &address, Imm32 imm, Label *label) {
-        ma_ldr(Operand(address.base, address.offset), ScratchRegister);
-        branchTest32(cond, ScratchRegister, imm, label);
+        // branchTest32 will use ScratchRegister.
+        load32(address, secondScratchReg_);
+        branchTest32(cond, secondScratchReg_, imm, label);
     }
     void branchTestPtr(Condition cond, const Register &lhs, const Register &rhs, Label *label) {
         branchTest32(cond, lhs, rhs, label);