PPC: Add new relocation type WASM_MEMORY_SIZE_REFERENCE, use relocatable pointers to update wasm memory size references in generated code.

Port 117a56b7c2

Original commit message:

     - Add new RelocInfo mode WASM_MEMORY_SIZE_REFERENCE in the assembler and add relocation information to immediates in compare instructions.
     - Use relocatable constants for MemSize/BoundsCheck in the wasm compiler

R=gdeepti@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=
LOG=N

Review-Url: https://codereview.chromium.org/1948263003
Cr-Commit-Position: refs/heads/master@{#36054}

src/compiler/ppc/code-generator-ppc.cc

@@ -1924,21 +1924,23 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
           destination->IsRegister() ? g.ToRegister(destination) : kScratchReg;
       switch (src.type()) {
         case Constant::kInt32:
-#if !V8_TARGET_ARCH_PPC64
+#if V8_TARGET_ARCH_PPC64
-          if (src.rmode() == RelocInfo::WASM_MEMORY_REFERENCE) {
+          if (src.rmode() == RelocInfo::WASM_MEMORY_SIZE_REFERENCE) {
+#else
+          if (src.rmode() == RelocInfo::WASM_MEMORY_REFERENCE ||
+              src.rmode() == RelocInfo::WASM_MEMORY_SIZE_REFERENCE) {
+#endif
             __ mov(dst, Operand(src.ToInt32(), src.rmode()));
           } else {
-#endif
             __ mov(dst, Operand(src.ToInt32()));
-#if !V8_TARGET_ARCH_PPC64
           }
-#endif
           break;
         case Constant::kInt64:
 #if V8_TARGET_ARCH_PPC64
           if (src.rmode() == RelocInfo::WASM_MEMORY_REFERENCE) {
             __ mov(dst, Operand(src.ToInt64(), src.rmode()));
           } else {
+            DCHECK(src.rmode() != RelocInfo::WASM_MEMORY_SIZE_REFERENCE);
 #endif
             __ mov(dst, Operand(src.ToInt64()));
 #if V8_TARGET_ARCH_PPC64

src/ppc/assembler-ppc-inl.h

@@ -89,11 +89,6 @@ Address RelocInfo::target_address() {
   return Assembler::target_address_at(pc_, host_);
 }
 
-Address RelocInfo::wasm_memory_reference() {
-  DCHECK(IsWasmMemoryReference(rmode_));
-  return Assembler::target_address_at(pc_, host_);
-}
-
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) ||
          rmode_ == EMBEDDED_OBJECT || rmode_ == EXTERNAL_REFERENCE);
@@ -183,19 +178,6 @@ Address Assembler::return_address_from_call_start(Address pc) {
   return pc + (len + 2) * kInstrSize;
 }
 
-void RelocInfo::update_wasm_memory_reference(
-    Address old_base, Address new_base, size_t old_size, size_t new_size,
-    ICacheFlushMode icache_flush_mode) {
-  DCHECK(IsWasmMemoryReference(rmode_));
-  DCHECK(old_base <= wasm_memory_reference() &&
-         wasm_memory_reference() < old_base + old_size);
-  Address updated_reference = new_base + (wasm_memory_reference() - old_base);
-  DCHECK(new_base <= updated_reference &&
-         updated_reference < new_base + new_size);
-  Assembler::set_target_address_at(isolate_, pc_, host_, updated_reference,
-                                   icache_flush_mode);
-}
-
 Object* RelocInfo::target_object() {
   DCHECK(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   return reinterpret_cast<Object*>(Assembler::target_address_at(pc_, host_));

src/ppc/assembler-ppc.cc

@@ -155,6 +155,43 @@ bool RelocInfo::IsInConstantPool() {
   return false;
 }
 
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Assembler::target_address_at(pc_, host_);
+}
+
+uint32_t RelocInfo::wasm_memory_size_reference() {
+  DCHECK(IsWasmMemorySizeReference(rmode_));
+  return static_cast<uint32_t>(
+     reinterpret_cast<intptr_t>(Assembler::target_address_at(pc_, host_)));
+}
+
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, uint32_t old_size, uint32_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_) || IsWasmMemorySizeReference(rmode_));
+  if (IsWasmMemoryReference(rmode_)) {
+    Address updated_memory_reference;
+    DCHECK(old_base <= wasm_memory_reference() &&
+           wasm_memory_reference() < old_base + old_size);
+    updated_memory_reference = new_base + (wasm_memory_reference() - old_base);
+    DCHECK(new_base <= updated_memory_reference &&
+           updated_memory_reference < new_base + new_size);
+    Assembler::set_target_address_at(
+        isolate_, pc_, host_, updated_memory_reference, icache_flush_mode);
+  } else if (IsWasmMemorySizeReference(rmode_)) {
+    uint32_t updated_size_reference;
+    DCHECK(wasm_memory_size_reference() <= old_size);
+    updated_size_reference =
+        new_size + (wasm_memory_size_reference() - old_size);
+    DCHECK(updated_size_reference <= new_size);
+    Assembler::set_target_address_at(
+        isolate_, pc_, host_, reinterpret_cast<Address>(updated_size_reference),
+        icache_flush_mode);
+  } else {
+    UNREACHABLE();
+  }
+}
 
 // -----------------------------------------------------------------------------
 // Implementation of Operand and MemOperand