diff mbox series

[v3,01/13] accel/tcg: Reduce CF_COUNT_MASK to match TCG_MAX_INSNS

Message ID 20210717221851.2124573-2-richard.henderson@linaro.org
State New
Headers show
Series tcg: breakpoint reorg | expand

Commit Message

Richard Henderson July 17, 2021, 10:18 p.m. UTC 
The space reserved for CF_COUNT_MASK was overly large.
Reduce to free up cflags bits and eliminate an extra test.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/exec/exec-all.h   | 4 +++-
 accel/tcg/translate-all.c | 5 ++---
 2 files changed, 5 insertions(+), 4 deletions(-)

Comments

Peter Maydell July 17, 2021, 11:33 p.m. UTC | #1 
On Sat, 17 Jul 2021 at 23:18, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The space reserved for CF_COUNT_MASK was overly large.
> Reduce to free up cflags bits and eliminate an extra test.
>
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox series

Patch

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 754f4130c9..dfe82ed19c 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -492,7 +492,9 @@  struct TranslationBlock {
     target_ulong cs_base; /* CS base for this block */
     uint32_t flags; /* flags defining in which context the code was generated */
     uint32_t cflags;    /* compile flags */
-#define CF_COUNT_MASK  0x00007fff
+
+/* Note that TCG_MAX_INSNS is 512; we validate this match elsewhere. */
+#define CF_COUNT_MASK  0x000001ff
 #define CF_LAST_IO     0x00008000 /* Last insn may be an IO access.  */
 #define CF_MEMI_ONLY   0x00010000 /* Only instrument memory ops */
 #define CF_USE_ICOUNT  0x00020000
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 4df26de858..5cc01d693b 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1428,11 +1428,10 @@  TranslationBlock *tb_gen_code(CPUState *cpu,
 
     max_insns = cflags & CF_COUNT_MASK;
     if (max_insns == 0) {
-        max_insns = CF_COUNT_MASK;
-    }
-    if (max_insns > TCG_MAX_INSNS) {
         max_insns = TCG_MAX_INSNS;
     }
+    QEMU_BUILD_BUG_ON(CF_COUNT_MASK + 1 != TCG_MAX_INSNS);
+
     if (cpu->singlestep_enabled || singlestep) {
         max_insns = 1;
     }