src/cpu/aarch64/vm/aarch64.ad

rev 12410 : 8171410: aarch64: long multiplyExact shifts by 31 instead of 63
Reviewed-by: aph

@@ -14084,19 +14084,19 @@
 %{
   match(Set cr (OverflowMulL op1 op2));
 
   format %{ "mul   rscratch1, $op1, $op2\t#overflow check long\n\t"
             "smulh rscratch2, $op1, $op2\n\t"
-            "cmp   rscratch2, rscratch1, ASR #31\n\t"
+            "cmp   rscratch2, rscratch1, ASR #63\n\t"
             "movw  rscratch1, #0x80000000\n\t"
             "cselw rscratch1, rscratch1, zr, NE\n\t"
             "cmpw  rscratch1, #1" %}
   ins_cost(6 * INSN_COST);
   ins_encode %{
     __ mul(rscratch1, $op1$$Register, $op2$$Register);   // Result bits 0..63
     __ smulh(rscratch2, $op1$$Register, $op2$$Register); // Result bits 64..127
-    __ cmp(rscratch2, rscratch1, Assembler::ASR, 31);    // Top is pure sign ext
+    __ cmp(rscratch2, rscratch1, Assembler::ASR, 63);    // Top is pure sign ext
     __ movw(rscratch1, 0x80000000);                    // Develop 0 (EQ),
     __ cselw(rscratch1, rscratch1, zr, Assembler::NE); // or 0x80000000 (NE)
     __ cmpw(rscratch1, 1);                             // 0x80000000 - 1 => VS
   %}
 

@@ -14110,19 +14110,19 @@
             || n->in(1)->as_Bool()->_test._test == BoolTest::no_overflow);
   effect(USE labl, KILL cr);
 
   format %{ "mul   rscratch1, $op1, $op2\t#overflow check long\n\t"
             "smulh rscratch2, $op1, $op2\n\t"
-            "cmp   rscratch2, rscratch1, ASR #31\n\t"
+            "cmp   rscratch2, rscratch1, ASR #63\n\t"
             "b$cmp $labl" %}
   ins_cost(4 * INSN_COST); // Branch is rare so treat as INSN_COST
   ins_encode %{
     Label* L = $labl$$label;
     Assembler::Condition cond = (Assembler::Condition)$cmp$$cmpcode;
     __ mul(rscratch1, $op1$$Register, $op2$$Register);   // Result bits 0..63
     __ smulh(rscratch2, $op1$$Register, $op2$$Register); // Result bits 64..127
-    __ cmp(rscratch2, rscratch1, Assembler::ASR, 31);    // Top is pure sign ext
+    __ cmp(rscratch2, rscratch1, Assembler::ASR, 63);    // Top is pure sign ext
     __ br(cond == Assembler::VS ? Assembler::NE : Assembler::EQ, *L);
   %}
 
   ins_pipe(pipe_serial);
 %}