[v4,04/19] tcg: Use tcg_constant_i32 with icount expander

Message ID 20200508182616.18318-5-richard.henderson@linaro.org
State Superseded
Headers show
Series
  • tcg: Better handling of constants
Related show

Commit Message

Richard Henderson May 8, 2020, 6:26 p.m.
We must do this before we adjust how tcg_out_movi_i32,
lest the under-the-hood poking that we do be broken.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 include/exec/gen-icount.h | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

-- 
2.20.1

Patch

diff --git a/include/exec/gen-icount.h b/include/exec/gen-icount.h
index 822c43cfd3..404732518a 100644
--- a/include/exec/gen-icount.h
+++ b/include/exec/gen-icount.h
@@ -34,7 +34,7 @@  static inline void gen_io_end(void)
 
 static inline void gen_tb_start(TranslationBlock *tb)
 {
-    TCGv_i32 count, imm;
+    TCGv_i32 count;
 
     tcg_ctx->exitreq_label = gen_new_label();
     if (tb_cflags(tb) & CF_USE_ICOUNT) {
@@ -48,15 +48,13 @@  static inline void gen_tb_start(TranslationBlock *tb)
                    offsetof(ArchCPU, env));
 
     if (tb_cflags(tb) & CF_USE_ICOUNT) {
-        imm = tcg_temp_new_i32();
-        /* We emit a movi with a dummy immediate argument. Keep the insn index
-         * of the movi so that we later (when we know the actual insn count)
-         * can update the immediate argument with the actual insn count.  */
-        tcg_gen_movi_i32(imm, 0xdeadbeef);
+        /*
+         * We emit a sub with a dummy immediate argument. Keep the insn index
+         * of the sub so that we later (when we know the actual insn count)
+         * can update the argument with the actual insn count.
+         */
+        tcg_gen_sub_i32(count, count, tcg_constant_i32(0));
         icount_start_insn = tcg_last_op();
-
-        tcg_gen_sub_i32(count, count, imm);
-        tcg_temp_free_i32(imm);
     }
 
     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label);
@@ -74,9 +72,12 @@  static inline void gen_tb_start(TranslationBlock *tb)
 static inline void gen_tb_end(TranslationBlock *tb, int num_insns)
 {
     if (tb_cflags(tb) & CF_USE_ICOUNT) {
-        /* Update the num_insn immediate parameter now that we know
-         * the actual insn count.  */
-        tcg_set_insn_param(icount_start_insn, 1, num_insns);
+        /*
+         * Update the num_insn immediate parameter now that we know
+         * the actual insn count.
+         */
+        tcg_set_insn_param(icount_start_insn, 2,
+                           tcgv_i32_arg(tcg_constant_i32(num_insns)));
     }
 
     gen_set_label(tcg_ctx->exitreq_label);