Re: [PATCH 1/3] target/mips: Use tcg_constant_tl() instead of tcg_gen_movi_tl()

[Richard Henderson]

On 10/4/24 13:26, Philippe Mathieu-Daudé wrote:

@@ -11428,17 +11415,12 @@ static void gen_compute_compact_branch(DisasContext 
*ctx, uint32_t opc,
  void gen_addiupc(DisasContext *ctx, int rx, int imm,
                   int is_64_bit, int extended)
  {
-    TCGv t0;
-
      if (extended && (ctx->hflags & MIPS_HFLAG_BMASK)) {
          gen_reserved_instruction(ctx);
          return;
      }

- t0 = tcg_temp_new();

-
-    tcg_gen_movi_tl(t0, pc_relative_pc(ctx));
-    tcg_gen_addi_tl(cpu_gpr[rx], t0, imm);
+    tcg_gen_addi_tl(cpu_gpr[rx], tcg_constant_tl(pc_relative_pc(ctx)), imm);
      if (!is_64_bit) {
          tcg_gen_ext32s_tl(cpu_gpr[rx], cpu_gpr[rx]);
      }

Oh dear.  All of this can be computed during translate.

    target_ulong val = pc_relative_pc(ctx) + imm;
    if (!is_64_bit) {
        val = (int32_t)val;
    }
    tcg_gen_movi_tl(cpu_gpr[rx], val);

diff --git a/target/mips/tcg/micromips_translate.c.inc 
b/target/mips/tcg/micromips_translate.c.inc
index 171508f7deb..d044592f83e 100644
--- a/target/mips/tcg/micromips_translate.c.inc
+++ b/target/mips/tcg/micromips_translate.c.inc
@@ -980,8 +980,7 @@ static void gen_ldst_pair(DisasContext *ctx, uint32_t opc, 
int rd,
          tcg_gen_qemu_ld_tl(t1, t0, ctx->mem_idx, mo_endian(ctx) | MO_SL |
                             ctx->default_tcg_memop_mask);
          gen_store_gpr(t1, rd);
-        tcg_gen_movi_tl(t1, 4);
-        gen_op_addr_add(ctx, t0, t0, t1);
+        gen_op_addr_add(ctx, t0, t0, tcg_constant_tl(4));

It might be useful to add a gen_op_addr_addi() helper.

Anyway, it's all an incremental improvement so,
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>


r~