8319406: x86: Shorter movptr(reg, imm) for 32-bit immediates

Reviewed-by: qamai, kvn

Author: shipilev

src/hotspot/cpu/x86/assembler_x86.cpp

@@ -13450,17 +13450,6 @@ void Assembler::movsbq(Register dst, Register src) {
   emit_int24(0x0F, (unsigned char)0xBE, (0xC0 | encode));
 }
 
-void Assembler::movslq(Register dst, int32_t imm32) {
-  // dbx shows movslq(rcx, 3) as movq     $0x0000000049000000,(%rbx)
-  // and movslq(r8, 3); as movl     $0x0000000048000000,(%rbx)
-  // as a result we shouldn't use until tested at runtime...
-  ShouldNotReachHere();
-  InstructionMark im(this);
-  int encode = prefixq_and_encode(dst->encoding());
-  emit_int8(0xC7 | encode);
-  emit_int32(imm32);
-}
-
 void Assembler::movslq(Address dst, int32_t imm32) {
   assert(is_simm32(imm32), "lost bits");
   InstructionMark im(this);

src/hotspot/cpu/x86/assembler_x86.hpp

@@ -1656,7 +1656,6 @@ class Assembler : public AbstractAssembler  {
 
   // Move signed 32bit immediate to 64bit extending sign
   void movslq(Address  dst, int32_t imm64);
-  void movslq(Register dst, int32_t imm64);
 
   void movslq(Register dst, Address src);
   void movslq(Register dst, Register src);

src/hotspot/cpu/x86/macroAssembler_x86.cpp

@@ -1339,7 +1339,12 @@ void MacroAssembler::call(AddressLiteral entry, Register rscratch) {
 
 void MacroAssembler::ic_call(address entry, jint method_index) {
   RelocationHolder rh = virtual_call_Relocation::spec(pc(), method_index);
+#ifdef _LP64
+  // Needs full 64-bit immediate for later patching.
+  mov64(rax, (intptr_t)Universe::non_oop_word());
+#else
   movptr(rax, (intptr_t)Universe::non_oop_word());
+#endif
   call(AddressLiteral(entry, rh));
 }
 
@@ -2562,7 +2567,15 @@ void MacroAssembler::movptr(Register dst, Address src) {
 
 // src should NEVER be a real pointer. Use AddressLiteral for true pointers
 void MacroAssembler::movptr(Register dst, intptr_t src) {
-  LP64_ONLY(mov64(dst, src)) NOT_LP64(movl(dst, src));
+#ifdef _LP64
+  if (is_simm32(src)) {
+    movq(dst, checked_cast<int32_t>(src));
+  } else {
+    mov64(dst, src);
+  }
+#else
+  movl(dst, src);
+#endif
 }
 
 void MacroAssembler::movptr(Address dst, Register src) {