Aurelien Jarno <aurel...@aurel32.net> writes:
> Now that copies and constants are tracked separately, we can allow
> constant to have copies, deferring the choice to use a register or a
> constant to the register allocation pass. This prevent this kind of
> regular constant reloading:
>
> -OUT: [size=338]
> +OUT: [size=298]
> mov -0x4(%r14),%ebp
> test %ebp,%ebp
> jne 0x7ffbe9cb0ed6
> mov $0x40002219f8,%rbp
> mov %rbp,(%r14)
> - mov $0x40002219f8,%rbp
> mov $0x4000221a20,%rbx
> mov %rbp,(%rbx)
> mov $0x4000000000,%rbp
> mov %rbp,(%r14)
> - mov $0x4000000000,%rbp
> mov $0x4000221d38,%rbx
> mov %rbp,(%rbx)
> mov $0x40002221a8,%rbp
> mov %rbp,(%r14)
> - mov $0x40002221a8,%rbp
> mov $0x4000221d40,%rbx
> mov %rbp,(%rbx)
> mov $0x4000019170,%rbp
> mov %rbp,(%r14)
> - mov $0x4000019170,%rbp
> mov $0x4000221d48,%rbx
> mov %rbp,(%rbx)
> mov $0x40000049ee,%rbp
> mov %rbp,0x80(%r14)
> mov %r14,%rdi
> callq 0x7ffbe99924d0
> mov $0x4000001680,%rbp
> mov %rbp,0x30(%r14)
> mov 0x10(%r14),%rbp
> mov $0x4000001680,%rbp
> mov %rbp,0x30(%r14)
> mov 0x10(%r14),%rbp
> shl $0x20,%rbp
> mov (%r14),%rbx
> mov %ebx,%ebx
> mov %rbx,(%r14)
> or %rbx,%rbp
> mov %rbp,0x10(%r14)
> mov %rbp,0x90(%r14)
> mov 0x60(%r14),%rbx
> mov %rbx,0x38(%r14)
> mov 0x28(%r14),%rbx
> mov $0x4000220e60,%r12
> mov %rbx,(%r12)
> mov $0x40002219c8,%rbx
> mov %rbp,(%rbx)
> mov 0x20(%r14),%rbp
> sub $0x8,%rbp
> mov $0x4000004a16,%rbx
> mov %rbx,0x0(%rbp)
> mov %rbp,0x20(%r14)
> mov $0x19,%ebp
> mov %ebp,0xa8(%r14)
> mov $0x4000015110,%rbp
> mov %rbp,0x80(%r14)
> xor %eax,%eax
> jmpq 0x7ffbebcae426
> lea -0x5f6d72a(%rip),%rax # 0x7ffbe3d437b3
> jmpq 0x7ffbebcae426
>
> Cc: Richard Henderson <r...@twiddle.net>
> Signed-off-by: Aurelien Jarno <aurel...@aurel32.net>
> ---
> tcg/optimize.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/tcg/optimize.c b/tcg/optimize.c
> index f16eb1e..48103b2 100644
> --- a/tcg/optimize.c
> +++ b/tcg/optimize.c
> @@ -237,11 +237,6 @@ static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op,
> TCGArg *args,
> return;
> }
>
> - if (temp_is_const(src)) {
> - tcg_opt_gen_movi(s, op, args, dst, temps[src].val);
> - return;
> - }
> -
That looks suspicious, surely we only want to drop the move if we
already have the const somewhere else?
> TCGOpcode new_op = op_to_mov(op->opc);
> tcg_target_ulong mask;
>
> @@ -255,17 +250,15 @@ static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op,
> TCGArg *args,
> }
> temps[dst].mask = mask;
>
> - assert(!temp_is_const(src));
> -
> if (s->temps[src].type == s->temps[dst].type) {
> if (!temp_is_copy(src)) {
> - temps[src].is_const = false;
> temps[src].is_copy = true;
> temps[src].next_copy = src;
> temps[src].prev_copy = src;
> }
> - temps[dst].is_const = false;
> + temps[dst].is_const = temps[src].is_const;
> temps[dst].is_copy = true;
> + temps[dst].val = temps[src].val;
> temps[dst].next_copy = temps[src].next_copy;
> temps[dst].prev_copy = src;
> temps[temps[dst].next_copy].prev_copy = dst;
--
Alex Bennée
