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target/hppa: Allow prior nullification in do_ibranch

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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>
This commit is contained in:
Richard Henderson 2024-03-21 14:33:28 -10:00
parent 2644f80ba5
commit d582c1faa3
1 changed files with 20 additions and 53 deletions
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73
target/hppa/translate.c
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@ -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);
return true;
}
/* 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. */
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