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>

diff --git a/target/alpha/translate.c b/target/alpha/translate.c
index 41151f002ea1b16b0c2e84231e7cd13105ae658b..b7b94cc378cbe635fd820dcfc7833ccfe1bd337a 100644 (file)
--- a/target/alpha/translate.c
+++ b/target/alpha/translate.c
@@ -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();
     }