Changeset 52977 in webkit for trunk/JavaScriptCore/assembler

Timestamp:

Jan 8, 2010, 12:01:40 AM (15 years ago)

Author:

[email protected]

Message:

Remove an unnecessary cacheFlush from ARM_TRADITIONAL JIT
​https://bugs.webkit.org/show_bug.cgi?id=33203

Reviewed by Gavin Barraclough.

• assembler/ARMAssembler.cpp: Remove obsolete linkBranch function.

(JSC::ARMAssembler::executableCopy): Inline a clean linkBranch code.

• assembler/ARMAssembler.h:

(JSC::ARMAssembler::getLdrImmAddress): Use inline function.
(JSC::ARMAssembler::getLdrImmAddressOnPool): Ditto.
(JSC::ARMAssembler::patchPointerInternal): Remove an unnecessary cacheFlush.
(JSC::ARMAssembler::linkJump): Use patchPointerInternal instead of linkBranch.
(JSC::ARMAssembler::linkCall): Ditto.
(JSC::ARMAssembler::relinkCall): Ditto.

Location:

trunk/JavaScriptCore/assembler

Files:

• ARMAssembler.cpp (modified) (2 diffs)
• ARMAssembler.h (modified) (5 diffs)

trunk/JavaScriptCore/assembler/ARMAssembler.cpp

@@ -35 +35 @@
 // Patching helpers
 
-ARMWord* ARMAssembler::getLdrImmAddress(ARMWord* insn, uint32_t* constPool)
-{
-    // Must be an ldr ..., [pc +/- imm]
-    ASSERT((*insn & 0x0f7f0000) == 0x051f0000);
-
-    if (constPool && (*insn & 0x1))
-        return reinterpret_cast<ARMWord*>(constPool + ((*insn & SDT_OFFSET_MASK) >> 1));
-
-    ARMWord addr = reinterpret_cast<ARMWord>(insn) + 2 * sizeof(ARMWord);
-    if (*insn & DT_UP)
-        return reinterpret_cast<ARMWord*>(addr + (*insn & SDT_OFFSET_MASK));
-    else
-        return reinterpret_cast<ARMWord*>(addr - (*insn & SDT_OFFSET_MASK));
-}
-
-void ARMAssembler::linkBranch(void* code, JmpSrc from, void* to, int useConstantPool)
-{
-    ARMWord* insn = reinterpret_cast<ARMWord*>(code) + (from.m_offset / sizeof(ARMWord));
-
-    if (!useConstantPool) {
-        int diff = reinterpret_cast<ARMWord*>(to) - reinterpret_cast<ARMWord*>(insn + 2);
-
-        if ((diff <= BOFFSET_MAX && diff >= BOFFSET_MIN)) {
-            *insn = B | getConditionalField(*insn) | (diff & BRANCH_MASK);
-            ExecutableAllocator::cacheFlush(insn, sizeof(ARMWord));
-            return;
-        }
-    }
-    ARMWord* addr = getLdrImmAddress(insn);
-    *addr = reinterpret_cast<ARMWord>(to);
-    ExecutableAllocator::cacheFlush(addr, sizeof(ARMWord));
-}
-
 void ARMAssembler::patchConstantPoolLoad(void* loadAddr, void* constPoolAddr)
 {
@@ -389 +356 @@
         int pos = (*iter) & (~0x1);
         ARMWord* ldrAddr = reinterpret_cast<ARMWord*>(data + pos);
-        ARMWord offset = *getLdrImmAddress(ldrAddr);
-        if (offset != 0xffffffff) {
-            JmpSrc jmpSrc(pos);
-            linkBranch(data, jmpSrc, data + offset, ((*iter) & 1));
+        ARMWord* addr = getLdrImmAddress(ldrAddr);
+        if (*addr != 0xffffffff) {
+            if (!(*iter & 1)) {
+                int diff = reinterpret_cast<ARMWord*>(data + *addr) - (ldrAddr + DefaultPrefetching);
+
+                if ((diff <= BOFFSET_MAX && diff >= BOFFSET_MIN)) {
+                    *ldrAddr = B | getConditionalField(*ldrAddr) | (diff & BRANCH_MASK);
+                    continue;
+                }
+            }
+            *addr = reinterpret_cast<ARMWord>(data + *addr);
         }
     }

trunk/JavaScriptCore/assembler/ARMAssembler.h

@@ -184 +184 @@
 
         static const ARMWord INVALID_IMM = 0xf0000000;
+        static const int DefaultPrefetching = 2;
 
         class JmpSrc {
@@ -633 +634 @@
         // Patching helpers
 
-        static ARMWord* getLdrImmAddress(ARMWord* insn, uint32_t* constPool = 0);
-        static void linkBranch(void* code, JmpSrc from, void* to, int useConstantPool = 0);
+        static ARMWord* getLdrImmAddress(ARMWord* insn)
+        {
+            // Must be an ldr ..., [pc +/- imm]
+            ASSERT((*insn & 0x0f7f0000) == 0x051f0000);
+
+            ARMWord addr = reinterpret_cast<ARMWord>(insn) + DefaultPrefetching * sizeof(ARMWord);
+            if (*insn & DT_UP)
+                return reinterpret_cast<ARMWord*>(addr + (*insn & SDT_OFFSET_MASK));
+            return reinterpret_cast<ARMWord*>(addr - (*insn & SDT_OFFSET_MASK));
+        }
+
+        static ARMWord* getLdrImmAddressOnPool(ARMWord* insn, uint32_t* constPool)
+        {
+            // Must be an ldr ..., [pc +/- imm]
+            ASSERT((*insn & 0x0f7f0000) == 0x051f0000);
+
+            if (*insn & 0x1)
+                return reinterpret_cast<ARMWord*>(constPool + ((*insn & SDT_OFFSET_MASK) >> 1));
+            return getLdrImmAddress(insn);
+        }
 
         static void patchPointerInternal(intptr_t from, void* to)
@@ -641 +660 @@
             ARMWord* addr = getLdrImmAddress(insn);
             *addr = reinterpret_cast<ARMWord>(to);
-            ExecutableAllocator::cacheFlush(addr, sizeof(ARMWord));
         }
 
@@ -686 +704 @@
         {
             ARMWord* insn = reinterpret_cast<ARMWord*>(m_buffer.data()) + (from.m_offset / sizeof(ARMWord));
-            *getLdrImmAddress(insn, m_buffer.poolAddress()) = static_cast<ARMWord>(to.m_offset);
+            ARMWord* addr = getLdrImmAddressOnPool(insn, m_buffer.poolAddress());
+            *addr = static_cast<ARMWord>(to.m_offset);
         }
 
         static void linkJump(void* code, JmpSrc from, void* to)
         {
-            linkBranch(code, from, to);
+            patchPointerInternal(reinterpret_cast<intptr_t>(code) + from.m_offset, to);
         }
 
@@ -701 +720 @@
         static void linkCall(void* code, JmpSrc from, void* to)
         {
-            linkBranch(code, from, to, true);
+            patchPointerInternal(reinterpret_cast<intptr_t>(code) + from.m_offset, to);
         }
 
         static void relinkCall(void* from, void* to)
         {
-            relinkJump(from, to);
+            patchPointerInternal(reinterpret_cast<intptr_t>(from) - sizeof(ARMWord), to);
         }