src/cpu/x86/vm/macroAssembler_x86.cpp

@@ -6655,11 +6655,11 @@
     jccb(Assembler::notZero, VECTOR_NOT_EQUAL);
     addptr(result, stride2);
     subl(cnt2, stride2);
     jccb(Assembler::notZero, COMPARE_WIDE_VECTORS_LOOP);
     // clean upper bits of YMM registers
-    vzeroupper();
+    vpxor(vec1, vec1);
 
     // compare wide vectors tail
     bind(COMPARE_WIDE_TAIL);
     testptr(result, result);
     jccb(Assembler::zero, LENGTH_DIFF_LABEL);

@@ -6670,11 +6670,11 @@
     jmpb(COMPARE_WIDE_VECTORS_LOOP);
 
     // Identifies the mismatching (higher or lower)16-bytes in the 32-byte vectors.
     bind(VECTOR_NOT_EQUAL);
     // clean upper bits of YMM registers
-    vzeroupper();
+    vpxor(vec1, vec1);
     lea(str1, Address(str1, result, scale));
     lea(str2, Address(str2, result, scale));
     jmp(COMPARE_16_CHARS);
 
     // Compare tail chars, length between 1 to 15 chars

@@ -6929,11 +6929,12 @@
 
   // That's it
   bind(DONE);
   if (UseAVX >= 2) {
     // clean upper bits of YMM registers
-    vzeroupper();
+    vpxor(vec1, vec1);
+    vpxor(vec2, vec2);
   }
 }
 
 void MacroAssembler::generate_fill(BasicType t, bool aligned,
                                    Register to, Register value, Register count,

@@ -7063,11 +7064,12 @@
         addptr(to, 32);
         subl(count, 8 << shift);
 
         BIND(L_check_fill_8_bytes);
         // clean upper bits of YMM registers
-        vzeroupper();
+        movdl(xtmp, value);
+        pshufd(xtmp, xtmp, 0);
       } else {
         // Fill 32-byte chunks
         pshufd(xtmp, xtmp, 0);
 
         subl(count, 8 << shift);

@@ -7226,11 +7228,15 @@
     jccb(Assembler::lessEqual, L_copy_16_chars);
 
     bind(L_copy_16_chars_exit);
     if (UseAVX >= 2) {
       // clean upper bits of YMM registers
-      vzeroupper();
+      vpxor(tmp2Reg, tmp2Reg);
+      vpxor(tmp3Reg, tmp3Reg);
+      vpxor(tmp4Reg, tmp4Reg);
+      movdl(tmp1Reg, tmp5);
+      pshufd(tmp1Reg, tmp1Reg, 0);
     }
     subptr(len, 8);
     jccb(Assembler::greater, L_copy_8_chars_exit);
 
     bind(L_copy_8_chars);