Mercurial > hg > truffle
diff src/cpu/x86/vm/x86_32.ad @ 671:d0994e5bebce
6822204: volatile fences should prefer lock:addl to actual mfence instructions
Reviewed-by: kvn, phh
author | never |
---|---|
date | Thu, 26 Mar 2009 14:31:45 -0700 |
parents | bd441136a5ce |
children | fbde8ec322d0 |
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--- a/src/cpu/x86/vm/x86_32.ad Tue Mar 24 15:09:52 2009 -0700 +++ b/src/cpu/x86/vm/x86_32.ad Thu Mar 26 14:31:45 2009 -0700 @@ -4288,24 +4288,6 @@ emit_opcode(cbuf, 0xC8 + $src2$$reg); %} - enc_class enc_membar_acquire %{ - // Doug Lea believes this is not needed with current Sparcs and TSO. - // MacroAssembler masm(&cbuf); - // masm.membar(); - %} - - enc_class enc_membar_release %{ - // Doug Lea believes this is not needed with current Sparcs and TSO. - // MacroAssembler masm(&cbuf); - // masm.membar(); - %} - - enc_class enc_membar_volatile %{ - MacroAssembler masm(&cbuf); - masm.membar(Assembler::Membar_mask_bits(Assembler::StoreLoad | - Assembler::StoreStore)); - %} - // Atomically load the volatile long enc_class enc_loadL_volatile( memory mem, stackSlotL dst ) %{ emit_opcode(cbuf,0xDF); @@ -7498,9 +7480,9 @@ ins_cost(400); size(0); - format %{ "MEMBAR-acquire" %} - ins_encode( enc_membar_acquire ); - ins_pipe(pipe_slow); + format %{ "MEMBAR-acquire ! (empty encoding)" %} + ins_encode(); + ins_pipe(empty); %} instruct membar_acquire_lock() %{ @@ -7519,9 +7501,9 @@ ins_cost(400); size(0); - format %{ "MEMBAR-release" %} - ins_encode( enc_membar_release ); - ins_pipe(pipe_slow); + format %{ "MEMBAR-release ! (empty encoding)" %} + ins_encode( ); + ins_pipe(empty); %} instruct membar_release_lock() %{ @@ -7535,12 +7517,22 @@ ins_pipe(empty); %} -instruct membar_volatile() %{ +instruct membar_volatile(eFlagsReg cr) %{ match(MemBarVolatile); + effect(KILL cr); ins_cost(400); - format %{ "MEMBAR-volatile" %} - ins_encode( enc_membar_volatile ); + format %{ + $$template + if (os::is_MP()) { + $$emit$$"LOCK ADDL [ESP + #0], 0\t! membar_volatile" + } else { + $$emit$$"MEMBAR-volatile ! (empty encoding)" + } + %} + ins_encode %{ + __ membar(Assembler::StoreLoad); + %} ins_pipe(pipe_slow); %}