Fix lots of crashes because of 4th argument register trampling.

https://bugs.webkit.org/show_bug.cgi?id=123421

Reviewed by Michael Saboff.

r3 register is the 4th argument register for ARM and also a scratch
register in the baseline JIT for this architecture. We can use r6
instead, as this used to be the timeoutCheckRegister and it is no
longer used since r148119.

* assembler/ARMAssembler.h: Temp register is now r6 instead of r3 for ARM.
* assembler/MacroAssemblerARMv7.h: Temp register is now r6 instead of r3 for ARMv7.
* dfg/DFGGPRInfo.h: Add r3 properly in GPRInfo for ARM.
* jit/JITStubs.cpp: Remove obsolete timeoutCheckRegister init.
* yarr/YarrJIT.cpp: Use r3 and not the new scratch register r6 and r8 register
doesn't need to be saved.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158208 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Change-Id: I5198a158e5e69d4e3a05b353abb60f28c0ab095e
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>

1 files changed, 3 insertions, 11 deletions

diff --git a/Source/JavaScriptCore/yarr/YarrJIT.cpp b/Source/JavaScriptCore/yarr/YarrJIT.cpp
index 1b2b03131..d337cf797 100644
--- a/Source/JavaScriptCore/yarr/YarrJIT.cpp
+++ b/Source/JavaScriptCore/yarr/YarrJIT.cpp
@@ -46,10 +46,10 @@ class YarrGenerator : private MacroAssembler {
     static const RegisterID input = ARMRegisters::r0;
     static const RegisterID index = ARMRegisters::r1;
     static const RegisterID length = ARMRegisters::r2;
-    static const RegisterID output = ARMRegisters::r4;
+    static const RegisterID output = ARMRegisters::r3;
 
-    static const RegisterID regT0 = ARMRegisters::r5;
-    static const RegisterID regT1 = ARMRegisters::r6;
+    static const RegisterID regT0 = ARMRegisters::r4;
+    static const RegisterID regT1 = ARMRegisters::r5;
 
     static const RegisterID returnRegister = ARMRegisters::r0;
     static const RegisterID returnRegister2 = ARMRegisters::r1;
@@ -2553,11 +2553,6 @@ class YarrGenerator : private MacroAssembler {
         push(ARMRegisters::r4);
         push(ARMRegisters::r5);
         push(ARMRegisters::r6);
-#if CPU(ARM_TRADITIONAL)
-        push(ARMRegisters::r8); // scratch register
-#endif
-        if (compileMode == IncludeSubpatterns)
-            move(ARMRegisters::r3, output);
 #elif CPU(SH4)
         push(SH4Registers::r11);
         push(SH4Registers::r13);
@@ -2583,9 +2578,6 @@ class YarrGenerator : private MacroAssembler {
         pop(X86Registers::ebx);
         pop(X86Registers::ebp);
 #elif CPU(ARM)
-#if CPU(ARM_TRADITIONAL)
-        pop(ARMRegisters::r8); // scratch register
-#endif
         pop(ARMRegisters::r6);
         pop(ARMRegisters::r5);
         pop(ARMRegisters::r4);