From d7f425fdea991f052241c6479acd9feae834063b Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 6 Oct 2018 09:05:30 -0700 Subject: [PATCH] tcg: Implement CPU_LOG_TB_NOCHAIN during expansion Rather than test NOCHAIN before linking, do not emit the goto_tb opcode at all. We already do this for goto_ptr. Signed-off-by: Richard Henderson --- accel/tcg/cpu-exec.c | 2 +- tcg/tcg-op.c | 9 ++++++++- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 6bcb6d99bd..870027d435 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -416,7 +416,7 @@ static inline TranslationBlock *tb_find(CPUState *cpu, } #endif /* See if we can patch the calling TB. */ - if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { + if (last_tb) { tb_add_jump(last_tb, tb_exit, tb); } return tb; diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c index daa416a143..7a8015c5a9 100644 --- a/tcg/tcg-op.c +++ b/tcg/tcg-op.c @@ -2586,6 +2586,10 @@ void tcg_gen_exit_tb(TranslationBlock *tb, unsigned idx) seen this numbered exit before, via tcg_gen_goto_tb. */ tcg_debug_assert(tcg_ctx->goto_tb_issue_mask & (1 << idx)); #endif + /* When not chaining, exit without indicating a link. */ + if (qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { + val = 0; + } } else { /* This is an exit via the exitreq label. */ tcg_debug_assert(idx == TB_EXIT_REQUESTED); @@ -2603,7 +2607,10 @@ void tcg_gen_goto_tb(unsigned idx) tcg_debug_assert((tcg_ctx->goto_tb_issue_mask & (1 << idx)) == 0); tcg_ctx->goto_tb_issue_mask |= 1 << idx; #endif - tcg_gen_op1i(INDEX_op_goto_tb, idx); + /* When not chaining, we simply fall through to the "fallback" exit. */ + if (!qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { + tcg_gen_op1i(INDEX_op_goto_tb, idx); + } } void tcg_gen_lookup_and_goto_ptr(void) -- 2.42.0