[sh4] Refactor jumps in baseline JIT to return label after the jump.

https://bugs.webkit.org/show_bug.cgi?id=123734

Patch by Julien Brianceau <jbriance@cisco.com> on 2013-11-04
Reviewed by Michael Saboff.

Current implementation of jumps in sh4 baseline JIT returns a label on the jump itself
and not after it. This is not correct and leads to issues like infinite loop the DFG
(https://bugs.webkit.org/show_bug.cgi?id=122597 for instance). This refactor fixes this
and also simplifies the link and relink procedures for sh4 jumps.

* assembler/MacroAssemblerSH4.h:
(JSC::MacroAssemblerSH4::branchDouble):
(JSC::MacroAssemblerSH4::branchTrue):
(JSC::MacroAssemblerSH4::branchFalse):
* assembler/SH4Assembler.h:
(JSC::SH4Assembler::jmp):
(JSC::SH4Assembler::extraInstrForBranch):
(JSC::SH4Assembler::jne):
(JSC::SH4Assembler::je):
(JSC::SH4Assembler::bra):
(JSC::SH4Assembler::linkJump):
(JSC::SH4Assembler::relinkJump):

Change-Id: Ia31b326a1f3c41e9c913e513563ff1e6b8f8e55e
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158580 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>

1 files changed, 10 insertions, 15 deletions

diff --git a/Source/JavaScriptCore/assembler/MacroAssemblerSH4.h b/Source/JavaScriptCore/assembler/MacroAssemblerSH4.h
index ad5acfaeb..c2293ed14 100644
--- a/Source/JavaScriptCore/assembler/MacroAssemblerSH4.h
+++ b/Source/JavaScriptCore/assembler/MacroAssemblerSH4.h
@@ -1452,10 +1452,9 @@ public:
             m_assembler.dcmppeq(right, right);
             takeBranch.append(Jump(m_assembler.jne(), SH4Assembler::JumpNear));
             m_assembler.dcmppeq(left, right);
-            Jump m_jump = Jump(m_assembler.je());
+            m_assembler.branch(BF_OPCODE, 2);
             takeBranch.link(this);
-            m_assembler.extraInstrForBranch(scratchReg3);
-            return m_jump;
+            return Jump(m_assembler.extraInstrForBranch(scratchReg3));
         }
 
         if (cond == DoubleGreaterThanOrUnordered) {
@@ -1466,10 +1465,9 @@ public:
             m_assembler.dcmppeq(right, right);
             takeBranch.append(Jump(m_assembler.jne(), SH4Assembler::JumpNear));
             m_assembler.dcmppgt(right, left);
-            Jump m_jump = Jump(m_assembler.je());
+            m_assembler.branch(BF_OPCODE, 2);
             takeBranch.link(this);
-            m_assembler.extraInstrForBranch(scratchReg3);
-            return m_jump;
+            return Jump(m_assembler.extraInstrForBranch(scratchReg3));
         }
 
         if (cond == DoubleGreaterThanOrEqualOrUnordered) {
@@ -1485,10 +1483,9 @@ public:
             m_assembler.dcmppeq(right, right);
             takeBranch.append(Jump(m_assembler.jne(), SH4Assembler::JumpNear));
             m_assembler.dcmppgt(left, right);
-            Jump m_jump = Jump(m_assembler.je());
+            m_assembler.branch(BF_OPCODE, 2);
             takeBranch.link(this);
-            m_assembler.extraInstrForBranch(scratchReg3);
-            return m_jump;
+            return Jump(m_assembler.extraInstrForBranch(scratchReg3));
         }
 
         if (cond == DoubleLessThanOrEqualOrUnordered) {
@@ -1504,17 +1501,15 @@ public:
     Jump branchTrue()
     {
         m_assembler.ensureSpace(m_assembler.maxInstructionSize + 6, sizeof(uint32_t));
-        Jump m_jump = Jump(m_assembler.je());
-        m_assembler.extraInstrForBranch(scratchReg3);
-        return m_jump;
+        m_assembler.branch(BF_OPCODE, 2);
+        return Jump(m_assembler.extraInstrForBranch(scratchReg3));
     }
 
     Jump branchFalse()
     {
         m_assembler.ensureSpace(m_assembler.maxInstructionSize + 6, sizeof(uint32_t));
-        Jump m_jump = Jump(m_assembler.jne());
-        m_assembler.extraInstrForBranch(scratchReg3);
-        return m_jump;
+        m_assembler.branch(BT_OPCODE, 2);
+        return Jump(m_assembler.extraInstrForBranch(scratchReg3));
     }
 
     Jump branch32(RelationalCondition cond, BaseIndex left, TrustedImm32 right)