target/alpha: Simplify gen_bcond_internal()

Richard Henderson explained on IRC:

  bcond_internal() used to insist that both branch
  destination and branch fallthrough are use_goto_tb;
  if not, we'd use movcond to compute an indirect jump.
  But it's perfectly fine for e.g. the branch fallthrough
  to use_goto_tb, and the branch destination to use
  an indirect branch.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240424234436.995410-4-richard.henderson@linaro.org>
[PMD: Split bigger patch, part 4/5]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20240503072014.24751-7-philmd@linaro.org>
This commit is contained in:
Philippe Mathieu-Daudé 2024-05-03 09:20:10 +02:00 committed by Richard Henderson
parent 9804ab26d0
commit 39482c2edc

View file

@ -461,23 +461,22 @@ static DisasJumpType gen_bcond_internal(DisasContext *ctx, TCGCond cond,
uint64_t dest = ctx->base.pc_next + disp;
TCGLabel *lab_true = gen_new_label();
if (use_goto_tb(ctx, dest)) {
tcg_gen_brcondi_i64(cond, cmp, imm, lab_true);
tcg_gen_brcondi_i64(cond, cmp, imm, lab_true);
if (use_goto_tb(ctx, ctx->base.pc_next)) {
tcg_gen_goto_tb(0);
tcg_gen_movi_i64(cpu_pc, ctx->base.pc_next);
tcg_gen_exit_tb(ctx->base.tb, 0);
gen_set_label(lab_true);
} else {
tcg_gen_movi_i64(cpu_pc, ctx->base.pc_next);
tcg_gen_lookup_and_goto_ptr();
}
gen_set_label(lab_true);
if (use_goto_tb(ctx, dest)) {
tcg_gen_goto_tb(1);
tcg_gen_movi_i64(cpu_pc, dest);
tcg_gen_exit_tb(ctx->base.tb, 1);
} else {
TCGv_i64 i = tcg_constant_i64(imm);
TCGv_i64 d = tcg_constant_i64(dest);
TCGv_i64 p = tcg_constant_i64(ctx->base.pc_next);
tcg_gen_movcond_i64(cond, cpu_pc, cmp, i, d, p);
tcg_gen_movi_i64(cpu_pc, dest);
tcg_gen_lookup_and_goto_ptr();
}