A bad try implementing overflow detection in C2 (2)

nogood_jump_if_overflow_x86.patch

diff --git a/src/cpu/x86/vm/x86_64.ad b/src/cpu/x86/vm/x86_64.ad
--- a/src/cpu/x86/vm/x86_64.ad
+++ b/src/cpu/x86/vm/x86_64.ad
@@ -10627,6 +10627,45 @@
   ins_pipe(pipe_jcc);
 %}
 
+instruct addI_ovf(rRegI dst, rRegI src, rFlagsReg cr)
+%{
+  effect(DEF cr, USE dst, USE src);
+
+  format %{ "addl    $dst, $src\t# int with overflow check" %}
+  opcode(0x03);
+  ins_encode(REX_reg_reg(dst, src), OpcP, reg_reg(dst, src));
+  ins_pipe(ialu_reg_reg);
+%}
+
+instruct jmpOvf(rFlagsReg cr, label labl)
+%{
+  effect(USE labl, USE cr);
+
+  format %{ "jo     $labl" %}
+  size(6);
+  ins_encode %{
+    Label* L = $labl$$label;
+    __ jcc(Assembler::overflow, *L, false); // Always long jump
+  %}
+  ins_pipe(pipe_jcc);
+%}
+
+// Jump Direct on Add Overflow
+instruct jmpAddOverflow(cmpOp cop, rRegI dst, rRegI src, rRegI sum, immI0 zero, label labl)
+%{
+  predicate( n->in(1)->as_Bool()->_test._test == BoolTest::lt &&
+             n->in(2)->in(1)->in(1)->in(2) == n->in(2)->in(1)->in(2)->in(2)
+            );
+  match(If cop (CmpI (AndI (XorI dst (AddI dst src)) (XorI src sum)) zero));
+
+  ins_cost(300);
+  expand %{
+    rFlagsReg cr;
+    addI_ovf(dst, src, cr);
+    jmpOvf(cr, labl);
+  %}
+%}
+
 // Jump Direct Conditional - Label defines a relative address from Jcc+1
 instruct jmpLoopEnd(cmpOp cop, rFlagsReg cr, label labl)
 %{
@@ -10828,6 +10867,20 @@
   ins_short_branch(1);
 %}
 
+instruct jmpOvf_short(rFlagsReg cr, label labl)
+%{
+  effect(USE labl, USE cr);
+
+  format %{ "jo,s     $labl" %}
+  size(2);
+  ins_encode %{
+    Label* L = $labl$$label;
+    __ jccb(Assembler::overflow, *L);
+  %}
+  ins_pipe(pipe_jcc);
+  ins_short_branch(1);
+%}
+
 // Jump Direct Conditional - Label defines a relative address from Jcc+1
 instruct jmpLoopEnd_short(cmpOp cop, rFlagsReg cr, label labl) %{
   match(CountedLoopEnd cop cr);