target/hppa: Allow prior nullification in do_ibranch

Simplify the function by not attempting a conditional move
on the branch destination -- just use nullify_over normally.

Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 21 insertions, 54 deletions

diff --git a/target/hppa/translate.c b/target/hppa/translate.c
index 4c42b518c5..140dfb747a 100644
--- a/target/hppa/translate.c
+++ b/target/hppa/translate.c
@@ -1871,17 +1871,15 @@ static bool do_cbranch(DisasContext *ctx, int64_t disp, bool is_n,
 static bool do_ibranch(DisasContext *ctx, TCGv_i64 dest,
                        unsigned link, bool is_n)
 {
-    TCGv_i64 a0, a1, next, tmp;
-    TCGCond c;
+    TCGv_i64 next;
 
-    assert(ctx->null_lab == NULL);
+    if (ctx->null_cond.c == TCG_COND_NEVER && ctx->null_lab == NULL) {
+        next = tcg_temp_new_i64();
+        tcg_gen_mov_i64(next, dest);
 
-    if (ctx->null_cond.c == TCG_COND_NEVER) {
         if (link != 0) {
             copy_iaoq_entry(ctx, cpu_gr[link], ctx->iaoq_n, ctx->iaoq_n_var);
         }
-        next = tcg_temp_new_i64();
-        tcg_gen_mov_i64(next, dest);
         if (is_n) {
             if (use_nullify_skip(ctx)) {
                 copy_iaoq_entry(ctx, cpu_iaoq_f, -1, next);
@@ -1895,60 +1893,29 @@ static bool do_ibranch(DisasContext *ctx, TCGv_i64 dest,
         }
         ctx->iaoq_n = -1;
         ctx->iaoq_n_var = next;
-    } else if (is_n && use_nullify_skip(ctx)) {
-        /* The (conditional) branch, B, nullifies the next insn, N,
-           and we're allowed to skip execution N (no single-step or
-           tracepoint in effect).  Since the goto_ptr that we must use
-           for the indirect branch consumes no special resources, we
-           can (conditionally) skip B and continue execution.  */
-        /* The use_nullify_skip test implies we have a known control path.  */
-        tcg_debug_assert(ctx->iaoq_b != -1);
-        tcg_debug_assert(ctx->iaoq_n != -1);
-
-        /* We do have to handle the non-local temporary, DEST, before
-           branching.  Since IOAQ_F is not really live at this point, we
-           can simply store DEST optimistically.  Similarly with IAOQ_B.  */
+        return true;
+    }
+
+    nullify_over(ctx);
+
+    if (is_n && use_nullify_skip(ctx)) {
         copy_iaoq_entry(ctx, cpu_iaoq_f, -1, dest);
         next = tcg_temp_new_i64();
         tcg_gen_addi_i64(next, dest, 4);
         copy_iaoq_entry(ctx, cpu_iaoq_b, -1, next);
-
-        nullify_over(ctx);
-        if (link != 0) {
-            copy_iaoq_entry(ctx, cpu_gr[link], ctx->iaoq_n, ctx->iaoq_n_var);
-        }
-        tcg_gen_lookup_and_goto_ptr();
-        return nullify_end(ctx);
+        nullify_set(ctx, 0);
     } else {
-        c = ctx->null_cond.c;
-        a0 = ctx->null_cond.a0;
-        a1 = ctx->null_cond.a1;
-
-        tmp = tcg_temp_new_i64();
-        next = tcg_temp_new_i64();
-
-        copy_iaoq_entry(ctx, tmp, ctx->iaoq_n, ctx->iaoq_n_var);
-        tcg_gen_movcond_i64(c, next, a0, a1, tmp, dest);
-        ctx->iaoq_n = -1;
-        ctx->iaoq_n_var = next;
-
-        if (link != 0) {
-            tcg_gen_movcond_i64(c, cpu_gr[link], a0, a1, cpu_gr[link], tmp);
-        }
-
-        if (is_n) {
-            /* The branch nullifies the next insn, which means the state of N
-               after the branch is the inverse of the state of N that applied
-               to the branch.  */
-            tcg_gen_setcond_i64(tcg_invert_cond(c), cpu_psw_n, a0, a1);
-            cond_free(&ctx->null_cond);
-            ctx->null_cond = cond_make_n();
-            ctx->psw_n_nonzero = true;
-        } else {
-            cond_free(&ctx->null_cond);
-        }
+        copy_iaoq_entry(ctx, cpu_iaoq_f, ctx->iaoq_b, cpu_iaoq_b);
+        copy_iaoq_entry(ctx, cpu_iaoq_b, -1, dest);
+        nullify_set(ctx, is_n);
     }
-    return true;
+    if (link != 0) {
+        copy_iaoq_entry(ctx, cpu_gr[link], ctx->iaoq_n, ctx->iaoq_n_var);
+    }
+
+    tcg_gen_lookup_and_goto_ptr();
+    ctx->base.is_jmp = DISAS_NORETURN;
+    return nullify_end(ctx);
 }
 
 /* Implement