PPC/s390: [wasm] No longer copy runtime stubs into each module.

Port a4b19dcc

Original Commit Message:

    This switches from copying entire runtime stubs into each module to only
    having small jump table slots in each module that act as a trampoline to
    the actual embedded builtin representing the runtime stub. This reduces
    the memory footprint of modules.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com, miladfar@ca.ibm.com
BUG=
LOG=N

Change-Id: Ibbe5fdf4d926b45582748ae8b15eb316107409dc
Reviewed-on: https://chromium-review.googlesource.com/c/1470455Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#59629}

src/wasm/jump-table-assembler.cc

@@ -146,6 +146,10 @@ void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
   b(r1);  // 2 bytes
 }
 
+void JumpTableAssembler::EmitRuntimeStubSlot(Address builtin_target) {
+  JumpToInstructionStream(builtin_target);
+}
+
 void JumpTableAssembler::EmitJumpSlot(Address target) {
   mov(r1, Operand(target));
   b(r1);
@@ -191,6 +195,10 @@ void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
   bctr();
 }
 
+void JumpTableAssembler::EmitRuntimeStubSlot(Address builtin_target) {
+  JumpToInstructionStream(builtin_target);
+}
+
 void JumpTableAssembler::EmitJumpSlot(Address target) {
   mov(r0, Operand(target));
   mtctr(r0);

src/wasm/jump-table-assembler.h

@@ -130,17 +130,13 @@ class JumpTableAssembler : public MacroAssembler {
   static constexpr int kJumpTableSlotSize = 3 * kInstrSize;
   static constexpr int kJumpTableStubSlotSize = 6 * kInstrSize;
 #elif V8_TARGET_ARCH_S390X
-  static constexpr int kJumpTableLineSize = 20;
+  static constexpr int kJumpTableLineSize = 128;
   static constexpr int kJumpTableSlotSize = 20;
-#elif V8_TARGET_ARCH_S390
-  static constexpr int kJumpTableLineSize = 14;
-  static constexpr int kJumpTableSlotSize = 14;
+  static constexpr int kJumpTableStubSlotSize = 14;
 #elif V8_TARGET_ARCH_PPC64
-  static constexpr int kJumpTableLineSize = 48;
+  static constexpr int kJumpTableLineSize = 64;
   static constexpr int kJumpTableSlotSize = 48;
-#elif V8_TARGET_ARCH_PPC
-  static constexpr int kJumpTableLineSize = 24;
-  static constexpr int kJumpTableSlotSize = 24;
+  static constexpr int kJumpTableStubSlotSize = 7 * kInstrSize;
 #elif V8_TARGET_ARCH_MIPS
   static constexpr int kJumpTableLineSize = 6 * kInstrSize;
   static constexpr int kJumpTableSlotSize = 6 * kInstrSize;